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Sample records for ground state rotational

  1. Optical cooling of AlH+ to the rotational ground state

    NASA Astrophysics Data System (ADS)

    Lien, Chien-Yu; Seck, Christopher; Odom, Brian

    2014-05-01

    We demonstrate cooling of the rotational degree of freedom of trapped diatomic molecular ions to the rotational ground state. The molecule of interested, AlH+, is co-trapped and sympathetically cooled with Ba+ to milliKelvin temperatures in its translational degree of freedom. The nearly diagonal Franck-Condon-Factors between the electronic X and A states of AlH+ create semi-closed cycling transitions between the vibrational ground states of X and A states. A spectrally filtered femtosecond laser is used to optically pump the population to the two lowest rotational levels, with opposite parities, in as fast as 100 μs via driving the A-X transition. In addition, a cooling scheme relying on vibrational relaxation brings the population to the N = 0 positive-parity level in as fast as 100 ms. The population distribution among the rotational levels is detected by resonance-enhanced multiphoton dissociation (REMPD) and time-of-flight mass-spectrometry (TOFMS). Although the current two-photon state readout scheme is destructive, a scheme of single-molecule fluorescence detection is also considered.

  2. Coulomb excitation of ground band rotational states in /sup 249/Bk

    SciTech Connect

    Bemis, C.E. Jr.; McGowan, F.K.; Ford, J.L.C. Jr.; Milner, W.T.; Robinson, R.L.; Stelson, P.H.

    1982-03-01

    Coulomb-excitation probabilities for the first few members of the 7/2/sup +/(633up-arrow) ground-state rotational band in /sup 249/Bk have been determined with 17.06-MeV /sup 4/He ions. These previously know excited states include the 9/2/sup +/ (41.8-keV), 11/2/sup +/ (93.7-keV), and 13/2/sup +/ (155.8-keV) members of the 7/2/sup +/(633up-arrow) band. Within experimental uncertainties, the Coulomb-excitation probabilities for these rotational states are reproduced by calculated values when only E2 excitations are considered with an intrinsic quadrupole moment, Q/sub 20/, of 12.70 +- 0.24 eb in the rigid rotor limit. The deduced ground-state spectroscopic quadrupole moment is 5.93 +- 0.11 eb. Intraband M1 transition rates have been deduced by combining the Q/sub 20/ result with other experimental data. Within the rotational model, a ground-state magnetic moment of +3.45 +- 0.10 ..mu../sub N/ is indicated.

  3. Laboratory rotational ground state transitions of NH3D+ and CF+

    NASA Astrophysics Data System (ADS)

    Stoffels, A.; Kluge, L.; Schlemmer, S.; Brünken, S.

    2016-09-01

    Aims: This paper reports accurate laboratory frequencies of the rotational ground state transitions of two astronomically relevant molecular ions, NH3D+ and CF+. Methods: Spectra in the millimetre-wave band were recorded by the method of rotational state-selective attachment of He atoms to the molecular ions stored and cooled in a cryogenic ion trap held at 4 K. The lowest rotational transition in the A state (ortho state) of NH3D+ (JK = 10-00), and the two hyperfine components of the ground state transition of CF+ (J = 1-0) were measured with a relative precision better than 10-7. Results: For both target ions, the experimental transition frequencies agree with recent observations of the same lines in different astronomical environments. In the case of NH3D+ the high-accuracy laboratory measurements lend support to its tentative identification in the interstellar medium. For CF+ the experimentally determined hyperfine splitting confirms previous quantum-chemical calculations and the intrinsic spectroscopic nature of a double-peaked line profile observed in the J = 1-0 transition towards the Horsehead photon-dominated region (PDR).

  4. The infrared rotation-vibration spectrum of dicyanoacetylene: The ground and v9 = 1 state rotational constants

    NASA Astrophysics Data System (ADS)

    Winther, F.; Schönhoff, M.; LePrince, R.; Guarnieri, A.; Bruget, D. N.; McNaughton, D.

    1992-03-01

    The bands ν5, ν6 + ν8, ν7 + ν8, ν6 + ν9, and ν8 of NCCCCN have been investigated in the gas phase with a resolution of 0.003 cm -1. The ground state rotational constants B0 = 0.04458699(10) cm -1 and D0 = 1.049(4) × 10 -9 cm -1 have been determined, together with the constants and the vibrational frequencies for the above bands. Several hot bands from the v9 = 1 state were analyzed to give B9 = 0.04468316(18) cm -1, D9 = 1.117(5) × 10 -9 cm -1, q9 = 3.85(2) × 10 -5 cm -1, and q9 J = 2.4(7) × 10 -11 cm -1. The bond lengths of NCCCCN correspond very closely to those of HCCCCCN.

  5. Rotational Spectra of Urea in its Ground and First Excited Vibrational States

    NASA Astrophysics Data System (ADS)

    Thomas, Jessica; Medvedev, Ivan; Kisiel, Zbigniew

    2014-06-01

    Urea is an important terrestrial bio-molecule, which has been tentatively detected in the interstellar medium. To match the much improved range and sensitivities of modern sub-millimeter telescopes a broad laboratory assay of rotational transitions needs to be recorded in order to aid in the definitive identification of this molecule. This paper focuses on the spectroscopic assignment of the rotational transitions of urea in the 207-500 GHz range which belong to its ground and first excited vibrational states. Remijan, A.J., L.E. Snyder, B.A. McGuire, H.-L. Kuo, L.W. Looney, D.N. Friedel, G.Y. Golubiatnikov, F.J. Lovas, V.V. Ilyushin, E.A. Alekseev, S.F. Dyubko, B.J. McCall, and J.M. Hollis, Observational Results of a Multi-Telescope Campaign in Search of Interstellar Urea [NH22CO]. The Astrophysical Journal, 2014. 783(2): p. 77

  6. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    SciTech Connect

    David R. Farley

    2010-08-19

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N≥3, with a rotational temperature between the wall and feed gas temperatures. The N=0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  7. Rotation vibration energy level clustering in the XB1 ground electronic state of PH2

    NASA Astrophysics Data System (ADS)

    Yurchenko, S. N.; Thiel, W.; Jensen, Per; Bunker, P. R.

    2006-10-01

    We use previously determined potential energy surfaces for the Renner-coupled XB1 and AA1 electronic states of the phosphino (PH 2) free radical in a calculation of the energies and wavefunctions of highly excited rotational and vibrational energy levels of the X˜ state. We show how spin-orbit coupling, the Renner effect, rotational excitation, and vibrational excitation affect the clustered energy level patterns that occur. We consider both 4-fold rotational energy level clustering caused by centrifugal distortion, and vibrational energy level pairing caused by local mode behaviour. We also calculate ab initio dipole moment surfaces for the X˜ and A˜ states, and the X˜-A˜ transition moment surface, in order to obtain spectral intensities.

  8. Classification of the ground states and topological defects in a rotating two-component Bose-Einstein condensate

    SciTech Connect

    Mason, Peter; Aftalion, Amandine

    2011-09-15

    We classify the ground states and topological defects of a rotating two-component condensate when varying several parameters: the intracomponent coupling strengths, the intercomponent coupling strength, and the particle numbers. No restriction is placed on the masses or trapping frequencies of the individual components. We present numerical phase diagrams which show the boundaries between the regions of coexistence, spatial separation, and symmetry breaking. Defects such as triangular coreless vortex lattices, square coreless vortex lattices, and giant skyrmions are classified. Various aspects of the phase diagrams are analytically justified thanks to a nonlinear {sigma} model that describes the condensate in terms of the total density and a pseudo-spin representation.

  9. Ab initio ground-state potential energy function and vibration-rotation energy levels of imidogen, NH.

    PubMed

    Koput, Jacek

    2015-06-30

    The accurate ground-state potential energy function of imidogen, NH, has been determined from ab initio calculations using the multireference averaged coupled-pair functional (MR-ACPF) method in conjunction with the correlation-consistent core-valence basis sets up to octuple-zeta quality. The importance of several effects, including electron correlation beyond the MR-ACPF level of approximation, the scalar relativistic, adiabatic, and nonadiabatic corrections were discussed. Along with the large one-particle basis set, all of these effects were found to be crucial to attain "spectroscopic" accuracy of the theoretical predictions of vibration-rotation energy levels of NH.

  10. The rotational spectra of the ground and first excited bending states of deuterium isocyanide, DNC, up to 2 THz

    NASA Astrophysics Data System (ADS)

    Brünken, S.; Müller, H. S. P.; Thorwirth, S.; Lewen, F.; Winnewisser, G.

    2006-01-01

    The pure rotational spectrum of deuterium isocyanide (DNC) was recorded in the frequency range from approximately 680 to 1985 GHz. Twenty-one new transitions in the vibrational ground and first excited bending states (01e,f 0) have been assigned, namely R-branch transitions from J=9-8 to 25-24. In a least squares analysis of these new transition frequencies together with previously reported millimeter-wave data, spectroscopic parameters up to sextic order could be derived with high precision for both states. Furthermore, the l-type doubling constant q and its centrifugal distortion terms qJ and qJJ were obtained for the first excited bending state.

  11. Rotationally resolved IR-diode laser studies of ground-state CO2 excited by collisions with vibrationally excited pyridine.

    PubMed

    Johnson, Jeremy A; Kim, Kilyoung; Mayhew, Maurine; Mitchell, Deborah G; Sevy, Eric T

    2008-03-27

    Relaxation of highly vibrationally excited pyridine (C5NH5) by collisions with carbon dioxide has been investigated using diode laser transient absorption spectroscopy. Vibrationally hot pyridine (E' = 40,660 cm(-1)) was prepared by 248 nm excimer laser excitation followed by rapid radiationless relaxation to the ground electronic state. Pyridine then collides with CO2, populating the high rotational CO2 states with large amounts of translational energy. The CO2 nascent rotational population distribution of the high-J (J = 58-80) tail of the 00(0)0 state was probed at short times following the excimer laser pulse to measure rate constants and probabilities for collisions populating these CO2 rotational states. Doppler spectroscopy was used to measure the CO2 recoil velocity distribution for J = 58-80 of the 00(0)0 state. The energy-transfer distribution function, P(E,E'), from E' - E approximately 1300-7000 cm(-1) was obtained by re-sorting the state-indexed energy-transfer probabilities as a function of DeltaE. P(E,E') is fit to an exponential or biexponential function to determine the average energy transferred in a single collision between pyridine and CO2. Also obtained are fit parameters that can be compared to previously studied systems (pyrazine, C6F6, methylpyrazine, and pyrimidine/CO2). Although the rotational and translational temperatures that describe pyridine/CO2 energy transfer are similar to previous systems, the energy-transfer probabilities are much smaller. P(E,E') fit parameters for pyridine/CO2 and the four previously studied systems are compared to various donor molecular properties. Finally, P(E,E') is analyzed in the context of two models, one indicating that P(E,E') shape is primarily determined by the low-frequency out-of-plane donor vibrational modes, and the other that indicates that P(E,E') shape can be determined from how the donor molecule final density of states changes with DeltaE.

  12. Torsion - Rotation - Vibration Effects in the Ground and First Excited States of Methacrolein and Methyl Vinyl Ketone

    NASA Astrophysics Data System (ADS)

    Zakharenko, Olena; Motiyenko, R. A.; Aviles Moreno, Juan-Ramon; Huet, T. R.

    2016-06-01

    Methacrolein and methyl vinyl ketone are the two major oxidation products of isoprene emitted in the troposphere. New spectroscopic information is provided with the aim to allow unambiguous identification of these molecules, characterized by a large amplitude motion associated with the methyl top. State-of-the-art millimeter-wave spectroscopy experiments coupled to quantum chemical calculations have been performed. Comprehensive sets of molecular parameters have been obtained. The torsion-rotation-vibration effects will be discussed in detail. From the atmospheric application point of view the results provide precise ground state molecular constants essential as a foundation (by using the Ground State Combination Differences method) for the analysis of high resolution spectrum, recorded from 600 to 1600 wn. The infrared range can be then refitted using appropriate Hamiltonian parameters. The present work is funded by the French ANR through the PIA under contract ANR-11-LABX-0005-01 (Labex CaPPA), by the Regional Council Nord-Pas de Calais and by the European Funds for Regional Economic Development (FEDER).

  13. The Rotational Spectrum of Chloryl Chloride, CICIO(sub 2), in its Ground Vibrational State

    NASA Technical Reports Server (NTRS)

    Cohen, E.; Muller, H.; Christen, D.

    1999-01-01

    Rotational spectra of the four main isotopomers of CICIO(sub 2) which together span the quantum numbers 10 < or = J < or = 77 and 0 < or = K(sub a) < or = 34 have been studied in selected regions between 10 and 417 GHz.

  14. Rotational energy surface and quasiclassical analysis of the rotational energy level cluster formation in the ground vibrational state of PH 3

    NASA Astrophysics Data System (ADS)

    Petrov, Sergey V.; Kozlovskii, Borislav M.

    2007-06-01

    We report and substantiate a method for constructing the rotational energy surface (RES) of a molecule as a pure classical object. For an arbitrary molecule we start from the potential energy surface rather than from a conventional "effective Hamiltonian". The method is used for constructing the RES of the PH 3 molecule in its ground vibrational state. We have used an ab initio potential energy surface [D. Wang, Q. Shi, Q.-S. Zhu, J. Chem. Phys. 112 (2000) 9624-9631; S.N. Yurchenko, M. Carvajal, P. Jensen, F. Herregodts, T.R. Huet, Chem. Phys. 290 (2003) 59-67.]. The shape of the RES is shown not to change for J from 0 to 120. The procedure of quasiclassical quantization of the RES was also undertaken, yielding a set of quasiclassical critical values of the angular momentum. The results explain the structure of quantum rotational energy levels obtained by variational calculations [S.N. Yurchenko, W. Thiel, S. Patchkovskii, P. Jensen, Phys. Chem. Chem. Phys. 7 (2005) 573-582].

  15. Torsional Splitting in the Rotational Spectrum from 8 TO 650 GHz of the Ground State of 1,1-DIFLUOROACETONE

    NASA Astrophysics Data System (ADS)

    Margules, L.; Motiyenko, R. A.; Groner, P.; De Chirico, F.; Turk, A.; Cooke, S. A.

    2013-06-01

    Measurements on the rotational spectrum of 1,1-difluoroacetone have been extended from the cm-wave region into the mm-wave region. Measurements between 150 GHz and 600 GHz were performed a t Lille at room temperature. About 2000 transitions have been added to the known line listing for the ground state. The range of J and K_{-1} values, for both the A and E torsional substates, now span 1 - 60 and 0 - 30, respectively. Analysis of the cm-wave spectrum was only possible using the Watson S-reduced Hamiltonian, with the A-reduction producing a poor spectral fit. For that analysis only quartic centrifugal distortion terms were required. With the newly recorded higher J and K_{-1} measurements it is necessary to expand the Hamiltonian to now include sextic and octic centrifugal distortion terms. This should allow us to extend the assignment to even higher J and K_{-1} and perhaps to shed more light into failure of the A-reduction Hamiltonian to achieve a satisfactory fit for the cm-wave transitions. The effective barrier to methyl group internal rotation has been determined more accurately. G. S. Grubbs II, P. Groner, S. E. Novick and S. A. Cooke J. Mol. Spectrosc. {280} 21-26, 2012.

  16. Progress in the Rotational Analysis of the Ground and Low-Lying Vibrationally Excited States of Malonaldehyde

    NASA Astrophysics Data System (ADS)

    Goudreau, E. S.; Tokaryk, Dennis W.; Ross, Stephen Cary; Billinghurst, Brant E.

    2016-06-01

    Despite being an important prototype molecule for intramolecular proton tunnelling, the far-IR spectrum of the internally hydrogen-bonded species malonaldehyde (C_3O_2H_4) is not yet well understood. In the talk I gave at the ISMS meeting in 2015 I discussed the high-resolution spectra we obtained at the Canadian Light Source synchrotron in Saskatoon, Saskatchewan. These spectra include a number of fundamental vibrational bands in the 100-2000 cm-1 region. In our efforts to analyze these bands we have noticed that our ground state combination differences show a large drift (up to an order of magnitude larger than our experimental error) away from those calculated using constants established by Baba et al., particularly in regions of high J (above 30) and low Ka (below 5). An examination of the previous microwave and far-IR studies reveals that this region of J-Ka space was not represented in the lines that Baba et al. used to generate the values for their fitting parameters. By including our own measurements in the fitting, we were able to improve the characterization of the ground state so that it is now consistent with all of the existing data. This characterization now covers a much larger range of J-Ka space and has enabled us to make significant progress in analyzing our far-IR synchrotron spectra. These include an excited vibrational state at 241 cm-1 as well as several states split by the tunnelling effect at higher wavenumber. T. Baba, T. Tanaka, I. Morino, K. M. T. Yamada, K. Tanaka. Detection of the tunneling-rotation transitions of malonaldehyde in the submillimeter-wave region. J. Chem. Phys., 110. 4131-4133 (1999) P. Turner, S. L. Baughcum, S. L. Coy, Z. Smith. Microwave Spectroscopic Study of Malonaldehyde. 4. Vibration-Rotation Interaction in Parent Species. J. Am. Chem. Soc., 106. 2265-2267 (1984) D. W. Firth, K. Beyer, M. A. Dvorak, S. W. Reeve, A. Grushow, K. R. Leopold. Tunable far-infrared spectroscopy of malonaldehyde. J. Chem. Phys., 94. 1812

  17. On the ground states and dynamics of space fractional nonlinear Schrödinger/Gross-Pitaevskii equations with rotation term and nonlocal nonlinear interactions

    NASA Astrophysics Data System (ADS)

    Antoine, Xavier; Tang, Qinglin; Zhang, Yong

    2016-11-01

    In this paper, we propose some efficient and robust numerical methods to compute the ground states and dynamics of Fractional Schrödinger Equation (FSE) with a rotation term and nonlocal nonlinear interactions. In particular, a newly developed Gaussian-sum (GauSum) solver is used for the nonlocal interaction evaluation [31]. To compute the ground states, we integrate the preconditioned Krylov subspace pseudo-spectral method [4] and the GauSum solver. For the dynamics simulation, using the rotating Lagrangian coordinates transform [14], we first reformulate the FSE into a new equation without rotation. Then, a time-splitting pseudo-spectral scheme incorporated with the GauSum solver is proposed to simulate the new FSE. In parallel to the numerical schemes, we also prove some existence and nonexistence results for the ground states. Dynamical laws of some standard quantities, including the mass, energy, angular momentum and the center of mass, are stated. The ground states properties with respect to the fractional order and/or rotating frequencies, dynamics involving decoherence and turbulence together with some interesting phenomena are reported.

  18. Rotational Spectrum of SO_3 and Theoretical Evidence for the Formation of Rotational Energy Level Clusters in its Vibrational Ground State

    NASA Astrophysics Data System (ADS)

    Underwood, Daniel S.; Yurchenko, Sergei N.; Tennyson, Jonathan; Jensen, Per

    2014-06-01

    The structure of the purely rotational spectrum of sulphur trioxide SO_3 is investigated using a new synthetic line list. The list combines line positions from an empirical model with line intensities determined, in the form of Einstein coefficients, from variationally computed ro-vibrational wavefunctions in conjunction with an ab initio dipole moment surface. The empirical model providing the line positions involves an effective, Watsonian-type rotational Hamiltonian with literature parameter values resulting from least-squares fittings to observed transition frequencies. The formation of so-called rotational energy clusters at high rotational excitation are investigated. The SO_3 molecule is planar at equilibrium and exhibits a unique type of rotational-energy clustering associated with unusual stabilization axes perpendicular to the S--O bonds. This behaviour is characterized theoretically in the J range from 100 through 250. The wavefunctions for these cluster states are analysed, and the results are compared to those of a classical analysis in terms of the rotational-energy-surface formalism.

  19. Effect of molecular-orbital rotations on ground-state energies in the parametric two-electron reduced density matrix method.

    PubMed

    Sand, Andrew M; Mazziotti, David A

    2013-06-28

    Different sets of molecular orbitals and the rotations connecting them are of great significance in molecular electronic structure. Most electron correlation methods depend on a reference wave function that separates the orbitals into occupied and unoccupied spaces. Energies and properties from these methods depend upon rotations between the spaces. Some electronic structure methods, such as modified coupled electron pair approximations and the recently developed parametric two-electron reduced density matrix (2-RDM) methods [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)], also depend upon rotations between occupied orbitals and rotations between unoccupied orbitals. In this paper, we explore the sensitivity of the ground-state energies from the parametric 2-RDM method to rotations within the occupied space and within the unoccupied space. We discuss the theoretical origin of the rotational dependence and provide computational examples at both equilibrium and non-equilibrium geometries. We also study the effect of these rotations on the size extensivity of the parametric 2-RDM method. Computations show that the orbital rotations have a small effect upon the parametric 2-RDM energies in comparison to the energy differences observed between methodologies such as coupled cluster and parametric 2-RDM. Furthermore, while the 2-RDM method is rigorously size extensive in a local molecular orbital basis set, calculations reveal negligible deviations in nonlocal molecular orbital basis sets such as those from canonical Hartree-Fock calculations.

  20. Rotational, steric, and coriolis effects on the F + HCl --> HF + Cl reaction on the 1(2)A' ground-state surface.

    PubMed

    Defazio, Paolo; Petrongolo, Carlo

    2009-04-23

    We present a quantum study of the reaction F((2)P) + HCl(X(1)Sigma(+)) --> HF(X(1)Sigma(+)) + Cl((2)P) on a recently computed 1(2)A' ground-state surface, considering HCl in the ground vibrational state, with up to 16 rotational quanta j(0). We employ the real wavepacket (WP) and flux methods for calculating coupled-channel (CC) and centrifugal-sudden (CS) initial-state probabilities up to J = 80 and 140, respectively. We also report CC and CS ground-state cross sections and CS excited-state cross sections and discuss the dynamics analyzing WP time evolutions. The HCl rotation highly enhances reaction probabilities and cross sections, as it was previously found for probabilities at J rotation to the F-H---Cl reactive vibration. WP snapshots confirm and explain the HCl rotational effects, because the density into the nearly collinear F-H---Cl product channel increases remarkably with j(0). Finally, our CS rate constant is underestimated with respect to the experiment, pointing out the need of more accurate multisurface and CC calculations.

  1. The ground states and pseudospin textures of rotating two-component Bose-Einstein condensates trapped in harmonic plus quartic potential

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Zhang, Su-Ying

    2016-09-01

    The ground states of two-component miscible Bose-Einstein condensates (BECs) confined in a rotating annular trap are obtained by using the Thomas-Fermi (TF) approximation method. The ground state density distribution of the condensates experiences a transition from a disc shape to an annulus shape either when the angular frequency increases and the width and the center height of the trap are fixed, or when the width and the center height of the trap increase and the angular frequency is fixed. Meantime the numerical solutions of the ground states of the trapped two-component miscible BECs with the same condition are obtained by using imaginary-time propagation method. They are in good agreement with the solutions obtained by the TF approximation method. The ground states of the trapped two-component immiscible BECs are also given by using the imaginary-time propagation method. Furthermore, by introducing a normalized complex-valued spinor, three kinds of pseudospin textures of the BECs, i.e., giant skyrmion, coaxial double-annulus skyrmion, and coaxial three-annulus skyrmion, are found. Project supported by the National Natural Science Foundation of China (Grant Nos. 91430109 and 11404198), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20111401110004), and the Natural Science Foundation of Shanxi Province, China (Grant No. 2014011005-3).

  2. Torsion-rotation-vibration effects in the ground and first excited states of methacrolein, a major atmospheric oxidation product of isoprene

    SciTech Connect

    Zakharenko, O.; Motiyenko, R. A.; Aviles Moreno, J.-R.; Huet, T. R.; Jabri, A.; Kleiner, I.

    2016-01-14

    Methacrolein is a major oxidation product of isoprene emitted in the troposphere. New spectroscopy information is provided with the aim to allow unambiguous identification of this complex molecule, characterized by a large amplitude motion associated with the methyl top. State-of-the-art millimeter-wave spectroscopy experiments coupled to quantum chemical calculations have been performed. For the most stable s-trans conformer of atmospheric interest, the torsional and rotational structures have been characterized for the ground state, the first excited methyl torsional state (ν{sub 27}), and the first excited skeletal torsional state (ν{sub 26}). The inverse sequence of A and E tunneling sub-states as well as anomalous A-E splittings observed for the rotational lines of v{sub 26} = 1 state clearly indicates a coupling between methyl torsion and skeletal torsion. A comprehensive set of molecular parameters has been obtained. The far infrared spectrum of Durig et al. [Spectrochim. Acta, Part A 42, 89–103 (1986)] was reproduced, and a Fermi interaction between ν{sub 25} and 2ν{sub 27} was evidenced.

  3. Examining Rotational Ground Motion Induced by Tornados

    NASA Astrophysics Data System (ADS)

    Kessler, Elijah; Dunn, Robert

    2016-03-01

    Ring lasers are well known for their ability to detect rotation and to serve as replacements for mechanical gyroscopes. The sensitivity of large ring lasers to various forms of ground motion is less familiar. Since ring lasers preferentially measure rotational ground motion and a standard seismograph is designed to measure translational and vertical ground motion, each device responds to different aspects of ground movement. Therefore, the two instruments will be used to explore responses to microseisms, earthquake generated shear waves, and in particular tornado generated ground movement. On April 27, 2014 an EF4 tornado devastated Vilonia, AR a small town ~ 21 km from the Hendrix College ring laser. The proximity of the tornado's path to the ring laser interferometer and to a seismograph located in Vilonia provided the opportunity to examine the response of these instruments to tornadic generated ground motion. Our measurements suggest tornadic weather systems can produce both rotational and lateral ground motion. This contention is supported by an after the fact damage survey which found that the tornado flattened a forest in which trees were uprooted and laid down in a pair of converging arcs with the centerline pointed in the direction of the tornado's path.

  4. Portable sensor technology for rotational ground motions

    NASA Astrophysics Data System (ADS)

    Bernauer, Felix; Wassermann, Joachim; Guattari, Frédéric; Igel, Heiner

    2016-04-01

    In this contribution we present performance characteristics of a single component interferometric fiber-optic gyroscope (IFOG). The prototype sensor is provided by iXBlue, France. It is tested in the framework of the European Research Council Project, ROMY (Rotational motions - a new observable for seismology), on its applicability as a portable and field-deployable sensor for rotational ground motions. To fully explore the benefits of this new seismic observable especially in the fields of vulcanology, ocean generated noise and geophysical exploration, such a sensor has to fulfill certain requirements regarding portability, power consumption, time stamping stability and dynamic range. With GPS-synchronized time stamping and miniseed output format, data acquisition is customized for the use in seismology. Testing time stamping accuracy yields a time shift of less than 0.0001 s and a correlation coefficient of 0.99 in comparison to a commonly used data acquisition system, Reftek 120. Sensor self-noise is below 5.0 ṡ 10-8 rads-1Hz-1/2 for a frequency band from 0.001 Hz to 5.0 Hz. Analysis of Allan deviation shows an angle random walk of 3.5 ṡ 10-8 rads-1Hz-1/2. Additionally, the operating range diagram is shown and ambient noise analysis is performed. The sensitivity of sensor self-noise to variations in surrounding temperature and magnetic field is tested in laboratory experiments. With a power consumption of less than 10 W, the whole system (single component sensor + data acquisition) is appropriate for field use with autonomous power supply.

  5. Impacts of Rotation Schemes on Ground-Dwelling Beneficial Arthropods.

    PubMed

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2016-10-01

    Crop rotation alters agroecosystem diversity temporally, and increasing the number of crops in rotation schemes can increase crop yields and reduce reliance on pesticides. We hypothesized that increasing the number of crops in annual rotation schemes would positively affect ground-dwelling beneficial arthropod communities. During 2012 and 2013, pitfall traps were used to measure activity-density and diversity of ground-dwelling communities within three previously established, long-term crop rotation studies located in Wisconsin and Illinois. Rotation schemes sampled included continuous corn, a 2-yr annual rotation of corn and soybean, and a 3-yr annual rotation of corn, soybean, and wheat. Insects captured were identified to family, and non-insect arthropods were identified to class, order, or family, depending upon the taxa. Beneficial arthropods captured included natural enemies, granivores, and detritivores. The beneficial community from continuous corn plots was significantly more diverse compared with the community in the 2-yr rotation, whereas the community in the 3-yr rotation did not differ from either rotation scheme. The activity-density of the total community and any individual taxa did not differ among rotation schemes in either corn or soybean. Crop species within all three rotation schemes were annual crops, and are associated with agricultural practices that make infield habitat subject to anthropogenic disturbances and temporally unstable. Habitat instability and disturbance can limit the effectiveness and retention of beneficial arthropods, including natural enemies, granivores, and detritivores. Increasing non-crop and perennial species within landscapes in conjunction with more diverse rotation schemes may increase the effect of biological control of pests by natural enemies.

  6. The effect of the earth's rotation on ground water motion.

    PubMed

    Loáiciga, Hugo A

    2007-01-01

    The average pore velocity of ground water according to Darcy's law is a function of the fluid pressure gradient and the gravitational force (per unit volume of ground water) and of aquifer properties. There is also an acceleration exerted on ground water that arises from the Earth's rotation. The magnitude and direction of this rotation-induced force are determined in exact mathematical form in this article. It is calculated that the gravitational force is at least 300 times larger than the largest rotation-induced force anywhere on Earth, the latter force being maximal along the equator and approximately equal to 34 N/m(3) there. This compares with a gravitational force of approximately 10(4) N/m(3).

  7. Control of Rotational Dynamics for Ground and Aerial Behavior.

    PubMed

    Zordan, Victor; Brown, David; Macchietto, Adriano; Yin, KangKang

    2014-10-01

    This paper proposes a physics-based framework to control rolling, flipping and other behaviors with significant rotational components. The proposed technique is a general approach for guiding coordinated action that can be layered over existing control architectures through the purposeful regulation of specific whole-body features. Namely, we apply control for rotation through the specification and execution of specific desired `rotation indices' for whole-body orientation, angular velocity and angular momentum control and highlight the use of the angular excursion as a means for whole-body rotation control. We account for the stylistic components of behaviors through reference posture control. The novelty of the described work includes control over behaviors with considerable rotational components, both on the ground and in the air as well as a number of characteristics useful for general control, such as flight planning with inertia modeling, compliant posture tracking, and contact control planning.

  8. Ground states of holographic superconductors

    SciTech Connect

    Gubser, Steven S.; Nellore, Abhinav

    2009-11-15

    We investigate the ground states of the Abelian Higgs model in AdS{sub 4} with various choices of parameters, and with no deformations in the ultraviolet other than a chemical potential for the electric charge under the Abelian gauge field. For W-shaped potentials with symmetry-breaking minima, an analysis of infrared asymptotics suggests that the ground state has emergent conformal symmetry in the infrared when the charge of the complex scalar is large enough. But when this charge is too small, the likeliest ground state has Lifshitz-like scaling in the infrared. For positive mass quadratic potentials, Lifshitz-like scaling is the only possible infrared behavior for constant nonzero values of the scalar. The approach to Lifshitz-like scaling is shown in many cases to be oscillatory.

  9. Software for inference of dynamic ground strains and rotations and their errors from short baseline array observations of ground motions

    USGS Publications Warehouse

    Spudich, Paul; Fletcher, Jon B.

    2009-01-01

    In two previous articles we presented a formulation for inferring the strains and rotations of the ground beneath a seismic array having a finite footprint. In this article we derive expressions for the error covariance matrices of the inferred strains and rotations, and we present software for the calculation of ground strains, rotations, and their variances from short baseline array ground-motion data.

  10. Ground-state Dirac monopole

    SciTech Connect

    Ruokokoski, E.; Moettoenen, M.

    2011-12-15

    We show theoretically that a monopole defect, analogous to the Dirac magnetic monopole, may exist as the ground state of a dilute spin-1 Bose-Einstein condensate. The ground-state monopole is not attached to a single semi-infinite Dirac string but forms a point where the circulation of a single vortex line is reversed. Furthermore, the three-dimensional dynamics of this monopole defect is studied after the magnetic field pinning the monopole is removed and the emergence of antimonopoles is observed. Our scheme is realizable with the current experimental facilities.

  11. Electronic ground state of Ni2+

    NASA Astrophysics Data System (ADS)

    Zamudio-Bayer, V.; Lindblad, R.; Bülow, C.; Leistner, G.; Terasaki, A.; v. Issendorff, B.; Lau, J. T.

    2016-11-01

    The 9/2 4Φ ground state of the Ni2+ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of 7.4 ±0.2 K was reached by buffer gas cooling of the molecular ion. The contribution of the spin dipole operator to the x-ray magnetic circular dichroism spin sum rule amounts to 7 Tz =0.17 ± 0.06 μB per atom, approximately 11% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of 3d transition metals seem to adopt maximum spin magnetic moments in their electronic ground states.

  12. Strongly Correlated States of Ultracold Rotating Dipolar Fermi Gases

    SciTech Connect

    Osterloh, Klaus; Barberan, Nuria; Lewenstein, Maciej

    2007-10-19

    We study strongly correlated ground and excited states of rotating quasi-2D Fermi gases constituted of a small number of dipole-dipole interacting particles with dipole moments polarized perpendicular to the plane of motion. As the number of atoms grows, the system enters an intermediate regime, where ground states are subject to a competition between distinct bulk-edge configurations. This effect obscures their description in terms of composite fermions and leads to the appearance of novel quasihole ground states. In the presence of dipolar interactions, the principal Laughlin state at filling {nu}=1/3 exhibits a substantial energy gap for neutral (total angular momentum conserving) excitations and is well-described as an incompressible Fermi liquid. Instead, at lower fillings, the ground state structure favors crystalline order.

  13. Can earthquake source inversion benefit from rotational ground motion observations?

    NASA Astrophysics Data System (ADS)

    Igel, H.; Donner, S.; Reinwald, M.; Bernauer, M.; Wassermann, J. M.; Fichtner, A.

    2015-12-01

    With the prospects of instruments to observe rotational ground motions in a wide frequency and amplitude range in the near future we engage in the question how this type of ground motion observation can be used to solve seismic inverse problems. Here, we focus on the question, whether point or finite source inversions can benefit from additional observations of rotational motions. In an attempt to be fair we compare observations from a surface seismic network with N 3-component translational sensors (classic seismometers) with those obtained with N/2 6-component sensors (with additional colocated 3-component rotational motions). Thus we keep the overall number of traces constant. Synthetic seismograms are calculated for known point- or finite-source properties. The corresponding inverse problem is posed in a probabilistic way using the Shannon information content as a measure how the observations constrain the seismic source properties. The results show that with the 6-C subnetworks the source properties are not only equally well recovered (even that would be benefitial because of the substantially reduced logistics installing N/2 sensors) but statistically significant some source properties are almost always better resolved. We assume that this can be attributed to the fact the (in particular vertical) gradient information is contained in the additional rotational motion components. We compare these effects for strike-slip and normal-faulting type sources. Thus the answer to the question raised is a definite "yes". The challenge now is to demonstrate these effects on real data.

  14. Rotational Spectra in 29 Vibrationally Excited States of Interstellar Aminoacetonitrile

    NASA Astrophysics Data System (ADS)

    Kolesniková, L.; Alonso, E. R.; Mata, S.; Alonso, J. L.

    2017-04-01

    We report a detailed spectroscopic investigation of the interstellar aminoacetonitrile, a possible precursor molecule of glycine. Using a combination of Stark and frequency-modulation microwave and millimeter wave spectroscopies, we observed and analyzed the room-temperature rotational spectra of 29 excited states with energies up to 1000 cm‑1. We also observed the 13C isotopologues in the ground vibrational state in natural abundance (1.1%). The extensive data set of more than 2000 new rotational transitions will support further identifications of aminoacetonitrile in the interstellar medium.

  15. Dynamics of molecules in extreme rotational states

    PubMed Central

    Yuan, Liwei; Teitelbaum, Samuel W.; Robinson, Allison; Mullin, Amy S.

    2011-01-01

    We have constructed an optical centrifuge with a pulse energy that is more than 2 orders of magnitude larger than previously reported instruments. This high pulse energy enables us to create large enough number densities of molecules in extreme rotational states to perform high-resolution state-resolved transient IR absorption measurements. Here we report the first studies of energy transfer dynamics involving molecules in extreme rotational states. In these studies, the optical centrifuge drives CO2 molecules into states with J ∼ 220 and we use transient IR probing to monitor the subsequent rotational, translational, and vibrational energy flow dynamics. The results reported here provide the first molecular insights into the relaxation of molecules with rotational energy that is comparable to that of a chemical bond.

  16. Rotational Spectra of Symmetric Top Molecules in Ground and Different Vibrational Excited States, and Phenomenon of Resonance – Applying in CF3CCH

    PubMed Central

    Motamedi, Masoud

    2007-01-01

    This paper deals with review of exploration of resonance in symmetric top molecules in different vibrational excited states, vt = n (n =1, 2, 3, 4). Calculations for CF3CCH shows that resonance take place at k=xℓℓ+(A-B)-2AζAζ-(A-B) and k=xℓℓ+(A-B)-2AζAζ-(A-B) for v10 = 2 and v10 = 3 respectively. In order to account for splitting about 3 MHz for the − 2 series in v10 = 4 is necessary to introduce the element 〈 J,k, ℓ|f24| J,k + 2, ℓ − 4〉 in fitting program.

  17. The Torsional Fundamental Band and Rotational Spectra up to 940 GHz of the Ground, First and Second Excited Torsional States of Acetone

    NASA Astrophysics Data System (ADS)

    Ilyushin, V.; Armieieva, Iuliia; Dorovskaya, Olga; Alekseev, E. A.; Tudorie, Marcela; Motiyenko, R. A.; Margulès, L.; Pirali, Olivier; Drouin, Brian

    2016-06-01

    A new global study of the acetone (CH_3)_2CO spectrum is reported. The new microwave measurements covering the frequency range from 34 GHz to 940 GHz have been carried out using spectrometers in IRA NASU (Ukraine) and PhLAM Lille (France). The far infrared spectrum of acetone has been recorded on the AILES beamline of the synchrotron SOLEIL using a Fourier transform infrared spectrometer coupled to a long path cell. The transitions belonging to the three lowest torsional states as well as to the observed fundamental band associated with the methyl-top torsion mode (νb{17} = 1) have been analyzed using recently developed model for the molecules with two equivalent methyl rotors and C2v symmetry at equilibrium (PAM_C2v_2tops program). The dataset consisting of more than 26100 microwave and 1100 FIR line frequencies and including transitions with J up to 89 was fit using a model consisting of 119 parameters and weighted root-mean-square deviation of 0.89 has been achieved. In the talk the details of this new study will be discussed. V. Ilyushin, J.T. Hougen J. Mol. Spectrosc. 289 (2013) 41-49.

  18. Toward Triplet Ground State NaLi Molecules

    NASA Astrophysics Data System (ADS)

    Ebadi, Sepehr; Jamison, Alan; Rvachov, Timur; Jing, Li; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2016-05-01

    The NaLi molecule is expected to have a long lifetime in the triplet ground-state due to its fermionic nature, large rotational constant, and weak spin-orbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. We have mapped the excited state NaLi triplet potential by means of photoassociation spectroscopy. We report on this and our further progress toward the creation of the triplet ground-state molecules using STIRAP. NSF, ARO-MURI, Samsung, NSERC.

  19. Ground-state stability and rotational activation parameters for individual rotamers of (R,S,S,R)-(N,N'-dimethyl-2,3-diaminobutane)PtG(2) complexes (G = 9-EtG, 3'-GMP, and 5'-GMP).

    PubMed

    Colonna, Gianpiero; Di Masi, Nicola G; Marzilli, Luigi G; Natile, Giovanni

    2003-02-24

    Rate constants for guanine rotation about the Pt-N7 bond in (R,S,S,R)-Me(2)DABPtG(2) complexes (Me(2)DAB = N,N'-dimethyl-2,3-diaminobutane; G = 9-EtG, 3'-GMP, and 5'-GMP) were evaluated from line-shape analysis of H8 resonances. Three diastereomers, two in head-to-tail (DeltaHT and LambdaHT) and one in head-to-head (HH) conformations, exist in equilibrium in solution. The two guanines are equivalent in DeltaHT and LambdaHT conformers and nonequivalent in the HH form; therefore, four rate constants (k(Delta)(HT), k(Lambda)(HT), k(HH)()s, and k(HH)()d; sub-subscripts s and d stand for H8-shielded and -deshielded guanine, respectively) were evaluated. Activation parameters (DeltaH and DeltaS) were evaluated from the rate constant dependence on temperature. High values of DeltaH (78-93 kJ mol(-)(1)) and DeltaS (51-71 J K(-)(1) mol(-)(1)) were found for G rotation in the preferred DeltaHT rotamer having the six-membered ring of each guanine more canted toward the cis-G and a favorable dipole-dipole internucleotide interaction. Lower values of DeltaH() (64-76 kJ mol(-)(1)) and very small values of DeltaS() (-7-11 J K(-)(1) mol(-)(1)) were found for G rotation in the less favorable LambdaHT rotamer, indicating that the ground-state entropy of this rotamer is close to that of the activated complex and the ground-state enthalpy closer to that of the activated complex than for the DeltaHT rotamer. For the two guanines in the HH rotamer there is no large difference in activation parameters. In general DeltaH falls in the range 66-84 kJ mol(-)(1) (rather close to the values for the LambdaHT rotamer) and DeltaS in the range 14-41 J K(-)(1) mol(-)(1). The equilibrium constant between HT and HH rotamers was also evaluated together with the corresponding thermodynamic parameters (DeltaH and DeltaS). It is found that the low enthalpy is the major stabilizing factor for DeltaHT as compared to HH, while the entropy factor would favor the latter rotamer. In contrast the greater

  20. The ground state of molecular hydrogen

    NASA Astrophysics Data System (ADS)

    Jennings, D. E.; Brault, J. W.

    1983-12-01

    The v = 0-0 quadrupole spectrum of H2 has been recorded using a 0.005-cm-1 resolution Fourier transform spectrometer. The rotational lines S(1) through S(5) are observable in the spectra, in the region 587 to 1447 cm-1. The spectral position for S(0) was also obtained from its v = 1-0 ground-state combination difference. The high accuracy of the H2 measurements has permitted a determination of four rotational constants. These are (in cm-1) B0 = 59.33455(6); D0 = 0.045682(4); H0 = 4.854(12) × 10-5 L0 = -5.41(12) × 10-8. The hydrogen line positions will facilitate studies of structure and dynamics in astrophysical objects exhibiting infrared H2 spectra. The absolute accuracy of frequency calibration over wide spectral ranges was verified using 10-μm CO2 and 3.39-μm CH4 laser frequencies. Standard frequencies for 5-μm CO were found to be high by 12 MHz (3.9 × 10-4 cm-1).

  1. Mono-deuterated dimethyl ether: laboratory spectrum up to 1 THz. Torsion-rotational spectrum within the vibrational ground-state for the symmetric and asymmetric conformers and first detection in IRAS 16293-2422

    NASA Astrophysics Data System (ADS)

    Richard, C.; Margulès, L.; Caux, E.; Kahane, C.; Ceccarelli, C.; Guillemin, J.-C.; Motiyenko, R. A.; Vastel, C.; Groner, P.

    2013-04-01

    Context. Dimethyl ether is one of the most abundant complex organic molecules (COMs) in star-forming regions. Like other COMs, its formation process is not yet clearly established, but the relative abundances of its deuterated isotopomers may provide crucial hints in studying its chemistry and tracing the source history. The mono-deuterated species (CHDOCH) is still a relatively light molecule compared to other COMs. Its spectrum is the most intense in the THz domain in the 100-150 K temperature regime, tracing the inner parts of the low-mass star-forming region. Therefore, it is necessary to measure and assign its transitions in this range in order to be able to compute accurate predictions required by astronomical observations, in particular with the telescope operating in the submm range, such as ALMA. Aims: We present the analysis of mono-deuterated dimethyl ether in its ground-vibrational state, based on an effective Hamiltonian for an asymmetric rotor molecules with internal rotors. The analysis covers the frequency range 150-990 GHz. Methods: The laboratory rotational spectrum of this species was measured with a submillimeter spectrometer (50-990 GHz) using solid-state sources. For the astronomical detection, we used the IRAM 30 m telescope to observe a total range of 27 GHz, in 4 frequency bands from 100 GHz to 219 GHz. Results: New sets of spectroscopic parameters have been determined by a least squares fit with the ERHAM code for both conformers. These parameters have permitted the first identification in space of both mono-deuterated DME isomers via detection of twenty transitions in the solar-type protostar IRAS 16293-2422 with the IRAM 30 m telescope. The DME deuteration ratio in this source appears as high as observed for methanol and formaldehyde, two species known to play an important role in the COMs formation history. Full Tables A.1, A.2, B.1, and B.2, which respectively give the measured (in laboratory) and predicted frequencies, are only

  2. Rotational spectra of the X 2Sigma(+) states of CaH and CaD

    NASA Technical Reports Server (NTRS)

    Frum, C. I.; Oh, J. J.; Cohen, E. A.; Pickett, H. M.

    1993-01-01

    The rotational spectra of the 2Sigma(2+) ground states of calcium monohydride and monodeuteride have been recorded in absorption between 250 and 700 GHz. The gas phase free radicals have been produced in a ceramic furnace by the reaction of elemental calcium with molecular hydrogen or deuterium in the presence of an electrical discharge. The molecular constants including the rotational constant, centrifugal distortion constants, spin-rotation constants, and magnetic hyperfine interaction constants have been extracted from the spectra.

  3. Effects of rotational states on the c/a ratio in solid hydrogens

    DOE PAGES

    Strzhemechny, Mikhail A.; Hemley, Russell J.

    2015-04-08

    We propose an approach to the problem of lattice distortions at low temperatures and ambient pressure in the solid hydrogens in their rotational ground states that explicitly accounts for the molecular nature of the constituent particles. The model is based on the idea that the second-order rotation-related correction to the ground-state energy depends on the lattice parameters. The calculated ground-state rotation-related contributions, δgs = c/a–(8/3)1/2, are negative for all species, amounting to about –1.5×10–5 for H2 and D2, whereas for HD this contribution is about –0.6×10–3, which is roughly 50 times larger. This substantial difference stems from the fact thatmore » the rotational dynamics in the homonuclear solids and in HD differ appreciably. Furthermore, the approach can be generalized to high pressures.« less

  4. Terahertz spectroscopy of ground state HD18O

    NASA Astrophysics Data System (ADS)

    Yu, Shanshan; Pearson, John C.; Drouin, Brian J.; Miller, Charles E.; Kobayashi, Kaori; Matsushima, Fusakazu

    2016-10-01

    Terahertz absorption spectroscopy was employed to measure the ground state pure rotational transitions of the water isotopologue HD18O . A total of 105 pure rotational transitions were observed in the 0.5-5.0 THz region with ∼ 100 kHz accuracy for the first time. The observed positions were fit to experimental accuracy using the Euler series expansion of the asymmetric-top Hamiltonian together with the literature Microwave, Far-IR and IR data in the ground state and ν2 . The new measurements and predictions reported here support the analysis of astronomical observations by high-resolution spectroscopic telescopes such as SOFIA and ALMA where laboratory rest frequencies with uncertainties of 1 MHz or less are required for proper analysis of velocity resolved astrophysical data.

  5. Ground states for nonuniform periodic Ising chains.

    PubMed

    Martínez-Garcilazo, J P; Ramírez, C

    2015-04-01

    We generalize Morita's works [J. Phys. A 7, 289 (1974); J. Phys. A 7, 1613 (1974)] on ground states of Ising chains, for chains with a periodic structure and different spins, to any interaction order. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. If there is parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular ground states. We illustrate the results and give the ground state diagrams in several cases.

  6. QED effects in molecules: test on rotational quantum states of H2.

    PubMed

    Salumbides, E J; Dickenson, G D; Ivanov, T I; Ubachs, W

    2011-07-22

    Quantum electrodynamic effects have been systematically tested in the progression of rotational quantum states in the X 1Σ(g)(+), v=0 vibronic ground state of molecular hydrogen. High-precision Doppler-free spectroscopy of the EF 1Σ(g)(+)-X 1Σ(g)(+) (0,0) band was performed with 0.005  cm(-1) accuracy on rotationally hot H2 (with rotational quantum states J up to 16). QED and relativistic contributions to rotational level energies as high as 0.13  cm(-1) are extracted, and are in perfect agreement with recent calculations of QED and high-order relativistic effects for the H2 ground state.

  7. Triplet (S = 1) Ground State Aminyl Diradical

    SciTech Connect

    Rajca, Andrzej; Shiraishi, Kouichi; Pink, Maren; Rajca, Suchada

    2008-04-02

    Aminyl diradical, which is stable in solution at low temperatures, is prepared. EPR spectra and SQUID magnetometry indicate that the diradical is planar and it possesses triplet ground state, with strong ferromagnetic coupling.

  8. On the ground state of metallic hydrogen

    NASA Technical Reports Server (NTRS)

    Chakravarty, S.; Ashcroft, N. W.

    1978-01-01

    A proposed liquid ground state of metallic hydrogen at zero temperature is explored and a variational upper bound to the ground state energy is calculated. The possibility that the metallic hydrogen is a liquid around the metastable point (rs = 1.64) cannot be ruled out. This conclusion crucially hinges on the contribution to the energy arising from the third order in the electron-proton interaction which is shown here to be more significant in the liquid phase than in crystals.

  9. Mimicking time evolution within a quantum ground state: Ground-state quantum computation, cloning, and teleportation

    SciTech Connect

    Mizel, Ari

    2004-07-01

    Ground-state quantum computers mimic quantum-mechanical time evolution within the amplitudes of a time-independent quantum state. We explore the principles that constrain this mimicking. A no-cloning argument is found to impose strong restrictions. It is shown, however, that there is flexibility that can be exploited using quantum teleportation methods to improve ground-state quantum computer design.

  10. Rotational state-dependent attachment of He atoms to cold molecular ions: An action spectroscopic scheme for rotational spectroscopy

    NASA Astrophysics Data System (ADS)

    Brünken, Sandra; Kluge, Lars; Stoffels, Alexander; Pérez-Ríos, Jesús; Schlemmer, Stephan

    2017-02-01

    We present a kinetics model description of a newly developed action spectroscopic method for rotational spectroscopy based on rotational state-dependent three-body attachment of He atoms to cold molecular ions stored in a cryogenic 22-pole ion trap. The model results from numerical simulations and an approximate analytical expression are compared to measurements of the J = 1- 0 rotational transition of CD+, for which we obtain a refined transition frequency of 453.5218509(7) GHz. From the analysis of the spectroscopic data recorded at varying experimental conditions, e.g. over a wide range of He number densities and excitation powers, we deduce that the ternary rate coefficient in the first excited rotational state of CD+ is reduced to (55 ± 5) % of the rotational ground state value. This decrease in the rate coefficient can be rationalized as an increase of the redissociation probability in the ternary collision process. A summary of rotational spectroscopy measurements of other molecular ions using the new method will be given, and its general applicability is discussed.

  11. Ground states for nonuniform periodic Ising chains

    NASA Astrophysics Data System (ADS)

    Martínez-Garcilazo, J. P.; Ramírez, C.

    2015-04-01

    We generalize Morita's works [J. Phys. A 7, 289 (1974), 10.1088/0305-4470/7/2/014; J. Phys. A 7, 1613 (1974), 10.1088/0305-4470/7/13/015] on ground states of Ising chains, for chains with a periodic structure and different spins, to any interaction order. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. If there is parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular ground states. We illustrate the results and give the ground state diagrams in several cases.

  12. Numerical Evaluation of 2D Ground States

    NASA Astrophysics Data System (ADS)

    Kolkovska, Natalia

    2016-02-01

    A ground state is defined as the positive radial solution of the multidimensional nonlinear problem \\varepsilon propto k_ bot 1 - ξ with the function f being either f(u) =a|u|p-1u or f(u) =a|u|pu+b|u|2pu. The numerical evaluation of ground states is based on the shooting method applied to an equivalent dynamical system. A combination of fourth order Runge-Kutta method and Hermite extrapolation formula is applied to solving the resulting initial value problem. The efficiency of this procedure is demonstrated in the 1D case, where the maximal difference between the exact and numerical solution is ≈ 10-11 for a discretization step 0:00025. As a major application, we evaluate numerically the critical energy constant. This constant is defined as a functional of the ground state and is used in the study of the 2D Boussinesq equations.

  13. Cavity optomechanics -- beyond the ground state

    NASA Astrophysics Data System (ADS)

    Meystre, Pierre

    2011-05-01

    The coupling of coherent optical systems to micromechanical devices, combined with breakthroughs in nanofabrication and in ultracold science, has opened up the exciting new field of cavity optomechanics. Cooling of the vibrational motion of a broad range on oscillating cantilevers and mirrors near their ground state has been demonstrated, and the ground state of at least one such system has now been reached. Cavity optomechanics offers much promise in addressing fundamental physics questions and in applications such as the detection of feeble forces and fields, or the coherent control of AMO systems and of nanoscale electromechanical devices. However, these applications require taking cavity optomechanics ``beyond the ground state.'' This includes the generation and detection of squeezed and other non-classical states, the transfer of squeezing between electromagnetic fields and motional quadratures, and the development of measurement schemes for the characterization of nanomechanical structures. The talk will present recent ``beyond ground state'' developments in cavity optomechanics. We will show how the magnetic coupling between a mechanical membrane and a BEC - or between a mechanical tuning fork and a nanoscale cantilever - permits to control and monitor the center-of-mass position of the mechanical system, and will comment on the measurement back-action on the membrane motion. We will also discuss of state transfer between optical and microwave fields and micromechanical devices. Work done in collaboration with Dan Goldbaum, Greg Phelps, Keith Schwab, Swati Singh, Steve Steinke, Mehmet Tesgin, and Mukund Vengallatore and supported by ARO, DARPA, NSF, and ONR.

  14. Steady States of the Parametric Rotator and Pendulum

    ERIC Educational Resources Information Center

    Bouzas, Antonio O.

    2010-01-01

    We discuss several steady-state rotation and oscillation modes of the planar parametric rotator and pendulum with damping. We consider a general elliptic trajectory of the suspension point for both rotator and pendulum, for the latter at an arbitrary angle with gravity, with linear and circular trajectories as particular cases. We treat the…

  15. NEW GROUND-STATE MEASUREMENTS OF ETHYL CYANIDE

    SciTech Connect

    Brauer, Carolyn S.; Pearson, John C.; Drouin, Brian J.; Yu, Shanshan

    2009-09-01

    The spectrum of ethyl cyanide, or propionitrile (CH{sub 3}CH{sub 2}CN), has been repeatedly observed in the interstellar medium with large column densities and surprisingly high temperatures in hot core sources. The construction of new, more sensitive, observatories accessing higher frequencies such as Herschel, ALMA, and SOFIA have made it important to extend the laboratory data for ethyl cyanide to coincide with the capabilities of the new instruments. We report extensions of the laboratory measurements of the rotational spectrum of ethyl cyanide in its ground vibrational state to 1.6 THz. A global analysis of the ground state, which includes all of the previous data and 3356 newly assigned transitions, has been fitted to within experimental error to J = 132, K = 36, using both Watson A-reduced and Watson S-reduced Hamiltonians.

  16. Measuring both Rotational and Translational Ground-Motions from Explosions and Local Earthquakes in Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, B.; Lee, W.; Lin, C.; Liu, C.; Shin, T.; Teng, T.; Wu, C.

    2008-12-01

    Since rotational motions can "contaminate" translational ground-motion measurements due to the induced perturbation of the Earth's gravitational field, we started a program to measure rotational ground motions near Hualien (Taiwan) in December, 2000. However, no useful data were obtained after 3 years, until a rotational sensor of much higher sensitivity was deployed at the HGSD station in eastern Taiwan in December, 2004. Rotational and translational seismograms were obtained from several hundred local earthquakes. As noted by several authors before, we found a linear relationship between peak rotational rate (PRR in mrad/s) and peak ground acceleration (PGA in m/s2) from local earthquakes in Taiwan: PRR = 0.002 + 1.301 PGA, with a correlation coefficient of 0.988. Taking advantage of two large explosions of the TAIGER Active Seismic Experiment, we deployed 13 accelerometers and 8 rotational sensors within 600 m from the N3 shot points and obtained some interesting results, which will be presented by Langston et al. in this Session. In December, 2007, we began an instrument array deployment along the Meishan fault in southwestern Taiwan, where a major earthquake occurred in 1906 with surface rupture of more than 12 km long. The deployed instruments are: (1) a 32-element seismic array in free-field, (2) a 32-element accelerometer array in a building, (3) a six-channel unit with a low-gain broadband seismometer and an accelerometer, and (4) two six-channel units with an accelerometer and an external rotational senor. We have 8 rotational sensors now deployed in Taiwan and seven new rotational sensors are scheduled for deployment soon in a program to assess the effect of ground rotation on traditional measurements of translational strong ground motions.

  17. Mass coefficient and Grodzins relation for the ground-state band and {gamma} band

    SciTech Connect

    Jolos, R. V.; Brentano, P. von

    2006-12-15

    It is shown that the available experimental data on the energies of the first and the {gamma}-vibrational 2{sup +} states and the reduced E2 transition probabilities from these states to the ground state require for the explanation significantly different values of the mass coefficients for the rotational motion and {gamma}-vibrations.

  18. Solid state replacement of rotating mirror cameras

    NASA Astrophysics Data System (ADS)

    Frank, Alan M.; Bartolick, Joseph M.

    2007-01-01

    Rotating mirror cameras have been the mainstay of mega-frame per second imaging for decades. There is still no electronic camera that can match a film based rotary mirror camera for the combination of frame count, speed, resolution and dynamic range. The rotary mirror cameras are predominantly used in the range of 0.1 to 100 micro-seconds per frame, for 25 to more than a hundred frames. Electron tube gated cameras dominate the sub microsecond regime but are frame count limited. Video cameras are pushing into the microsecond regime but are resolution limited by the high data rates. An all solid state architecture, dubbed 'In-situ Storage Image Sensor' or 'ISIS', by Prof. Goji Etoh has made its first appearance into the market and its evaluation is discussed. Recent work at Lawrence Livermore National Laboratory has concentrated both on evaluation of the presently available technologies and exploring the capabilities of the ISIS architecture. It is clear though there is presently no single chip camera that can simultaneously match the rotary mirror cameras, the ISIS architecture has the potential to approach their performance.

  19. Solid State Replacement of Rotating Mirror Cameras

    SciTech Connect

    Frank, A M; Bartolick, J M

    2006-08-25

    Rotating mirror cameras have been the mainstay of mega-frame per second imaging for decades. There is still no electronic camera that can match a film based rotary mirror camera for the combination of frame count, speed, resolution and dynamic range. The rotary mirror cameras are predominantly used in the range of 0.1 to 100 micro-seconds per frame, for 25 to more than a hundred frames. Electron tube gated cameras dominate the sub microsecond regime but are frame count limited. Video cameras are pushing into the microsecond regime but are resolution limited by the high data rates. An all solid state architecture, dubbed ''In-situ Storage Image Sensor'' or ''ISIS'', by Prof. Goji Etoh, has made its first appearance into the market and its evaluation is discussed. Recent work at Lawrence Livermore National Laboratory has concentrated both on evaluation of the presently available technologies and exploring the capabilities of the ISIS architecture. It is clear though there is presently no single chip camera that can simultaneously match the rotary mirror cameras, the ISIS architecture has the potential to approach their performance.

  20. Individual Atoms in their Quantum Ground State

    NASA Astrophysics Data System (ADS)

    Schwartz, Eyal; Sompet, Pimonpan; Fung, Yin Hsien; Andersen, Mikkel F.

    2016-05-01

    An ultimate control of pure quantum states is an excellent platform for various quantum science and engineering. In this work, we perform quantum manipulation of individual Rubidium atoms in a tightly focus optical tweezer in order to cool them into their vibrational ground state via Raman sideband cooling. Our experimental scheme involves a combination of Raman sideband transitions and optical pumping of the atoms that couples two magnetic field sublevels indifferent to magnetic noise thus providing a much longer atomic coherence time compared to previous cooling schemes. By installing most of the atoms in their ground state, we managed to achieve two-dimensional cooling on the way to create a full nil entropy quantum state of single atoms and single molecules. We acknowledge the Marsden Fund, CORE and DWC for their support.

  1. Short Rotation Crops in the United States

    SciTech Connect

    Wright, L L

    1998-06-04

    The report is based primarily on the results of survey questions sent to approximately 60 woody and 20 herbaceous crop researchers in the United States and on information from the U.S. Department of Energy's Bioenergy Feedstock Development Program. Responses were received from 13 individuals involved in woody crops research or industrial commercialization (with 5 of the responses coming from industry). Responses were received from 11 individuals involved in herbaceous crop research. Opinions on market incentives, technical and non-technical barriers, and highest priority research and development areas are summarized in the text. Details on research activities of the survey responders are provided as appendices to the paper. Woody crops grown as single-stem systems (primarily Populus and Eucalyptus species) are perceived to have strong pulp fiber and oriented strand board markets, and the survey responders anticipated that energy will comprise 25% or less of the utilization of single-stem short-rotation woody crops between now and 2010. The only exception was a response from California where a substantial biomass energy market does currently exist. Willows (Salix species) are only being developed for energy and only in one part of the United States at present. Responses from herbaceous crop researchers suggested frustration that markets (including biomass energy markets) do not currently exist for the crop, and it was the perception of many that federal incentives will be needed to create such markets. In all crops, responses indicate that a wide variety of research and development activities are needed to enhance the yields and profitability of the crops. Ongoing research activities funded by the U.S. Department of Energy's Bioenergy Feedstock Development Program are described in an appendix to the paper.

  2. A high precision, compact electromechanical ground rotation sensor.

    PubMed

    Dergachev, V; DeSalvo, R; Asadoor, M; Bhawal, A; Gong, P; Kim, C; Lottarini, A; Minenkov, Y; Murphy, C; O'Toole, A; Peña Arellano, F E; Rodionov, A V; Shaner, M; Sobacchi, E

    2014-05-01

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10⁻¹¹ m/√Hz. We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10⁻⁹ rad/√Hz at 10 mHz and 6.4 × 10⁻¹⁰ rad/√Hz at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

  3. A high precision, compact electromechanical ground rotation sensor

    SciTech Connect

    Dergachev, V.; DeSalvo, R.; Asadoor, M.; Bhawal, A.; Gong, P.; Kim, C.; Lottarini, A.; Minenkov, Y.; Murphy, C.; O'Toole, A.; Peña Arellano, F. E.; and others

    2014-05-15

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10{sup −11}m/√( Hz ). We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10{sup −9} rad /√( Hz ) at 10 mHz and 6.4 × 10{sup −10} rad /√( Hz ) at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

  4. Trapping cold ground state argon atoms.

    PubMed

    Edmunds, P D; Barker, P F

    2014-10-31

    We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).

  5. Ground state structures in ferrofluid monolayers.

    PubMed

    Prokopieva, Taisia A; Danilov, Victor A; Kantorovich, Sofia S; Holm, Christian

    2009-09-01

    A combination of analytical calculations and Monte Carlo simulations is used to find the ground state structures in monodisperse ferrofluid monolayers. Taking into account the magnetic dipole-dipole interaction between all particles in the system we observe different topological structures that are likely to exist at low temperatures. The most energetically favored structures we find are rings, embedded rings, and rings side by side, and we are able to derive analytical expressions for the total energy of these structures. A detailed analysis of embedded rings and rings side by side shows that the interring interactions are negligible. We furthermore find that a single ideal ring is the ground state structure for a ferrofluid monolayer. We compared our theoretical predictions to the results of simulated annealing data and found them to be in excellent agreement.

  6. Approximate theoretical model for the five electronic states ( Ω = 5/2, 3/2, 3/2, 1/2, 1/2) arising from the ground 3d 9 configuration in nickel halide molecules and for rotational levels of the two Ω = 1/2 states in that manifold

    NASA Astrophysics Data System (ADS)

    Hougen, Jon T.

    2011-05-01

    In the first part of this paper an effective Hamiltonian for a non-rotating diatomic molecule containing only crystal-field and spin-orbit operators is set up to describe the energies of the five spin-orbit components that arise in the ground electronic configuration of the nickel monohalides. The model assumes that bonding in the nickel halides has the approximate form Ni +X -, with an electronic 3d 9 configuration plus closed shells on the Ni + moiety and a closed shell configuration on the X - moiety. From a crystal-field point of view, interactions of the positive d-hole with the cylindrically symmetrical electric charge distribution of the hypothetical NiX - closed-shell core can then be parameterized by three terms in a traditional expansion in spherical harmonics: C0 + C2Y20( θ, ϕ) + C4Y40( θ, ϕ). Interaction of the hole with the magnetic field generated by its own orbital motion can be parameterized by a traditional spin-orbit interaction operator A L · S. The Hamiltonian matrix is set up in a basis set consisting of the 10 Hund's case (a) basis functions | L, Λ; S , Σ> that arise when L = 2 and S = 1/2. Least-squares fits of the observed five spin-orbit components of the three lowest electronic states in NiF and NiCl are then carried out in terms of the four parameters C0, C2, C4, and A which lead to good agreement, except for the two | Ω| = 1/2 states. The large equal and opposite residuals of the | Ω| = 1/2 states can be reduced to values comparable with those for the | Ω| = 3/2 and | Ω| = 5/2 states by fixing A to its value in Ni + and then introducing an empirical correction factor for one off-diagonal orbital matrix element. In the second part of this paper the usual effective Hamiltonian B( J- L- S) 2 for a rotating diatomic molecule is used to derive expressions for the Ω-type doubling parameter p in the two | Ω| = 1/2 states. These expressions show (for certain sign conventions) that the sum of the two p values should be -2 B, but that

  7. Ground state searches in fcc intermetallics

    SciTech Connect

    Wolverton, C.; de Fontaine, D. ); Ceder, G. ); Dreysse, H. . Lab. de Physique du Solide)

    1991-12-01

    A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.

  8. Optical Characterization of Deep-Space Object Rotation States

    DTIC Science & Technology

    2014-09-01

    characterize non-resolvable object rotation states, focusing on objects well above low- Earth orbit altitudes. 3 OBSERVATIONS OF NON-RESOLVED ROTATING...OBJECTS This analysis focuses on broad-band temporal photometry of Earth -orbiting satellites (i.e., time-series measurements of whole-object...order. Upper-stages from rockets that have launched satellites into orbit represent one of the most common types of rotating object in Earth orbit

  9. Rotating columns: relating structure-from-motion, accretion/deletion, and figure/ground.

    PubMed

    Froyen, Vicky; Feldman, Jacob; Singh, Manish

    2013-08-14

    We present a novel phenomenon involving an interaction between accretion deletion, figure-ground interpretation, and structure-from-motion. Our displays contain alternating light and dark vertical regions in which random-dot textures moved horizontally at constant speed but in opposite directions in alternating regions. This motion is consistent with all the light regions in front, with the dark regions completing amodally into a single large surface moving in the background, or vice versa. Surprisingly, the regions that are perceived as figural are also perceived as 3-D volumes rotating in depth (like rotating columns)-despite the fact that dot motion is not consistent with 3-D rotation. In a series of experiments, we found we could manipulate which set of regions is perceived as rotating volumes simply by varying known geometric cues to figure ground, including convexity, parallelism, symmetry, and relative area. Subjects indicated which colored regions they perceived as rotating. For our displays we found convexity to be a stronger cue than either symmetry or parallelism. We furthermore found a smooth monotonic decay of the proportion by which subjects perceive symmetric regions as figural, as a function of their relative area. Our results reveal an intriguing new interaction between accretion-deletion, figure-ground, and 3-D motion that is not captured by existing models. They also provide an effective tool for measuring figure-ground perception.

  10. Reducing collective quantum state rotation errors with reversible dephasing

    SciTech Connect

    Cox, Kevin C.; Norcia, Matthew A.; Weiner, Joshua M.; Bohnet, Justin G.; Thompson, James K.

    2014-12-29

    We demonstrate that reversible dephasing via inhomogeneous broadening can greatly reduce collective quantum state rotation errors, and observe the suppression of rotation errors by more than 21 dB in the context of collective population measurements of the spin states of an ensemble of 2.1×10{sup 5} laser cooled and trapped {sup 87}Rb atoms. The large reduction in rotation noise enables direct resolution of spin state populations 13(1) dB below the fundamental quantum projection noise limit. Further, the spin state measurement projects the system into an entangled state with 9.5(5) dB of directly observed spectroscopic enhancement (squeezing) relative to the standard quantum limit, whereas no enhancement would have been obtained without the suppression of rotation errors.

  11. Rotationally resolved state-to-state photoelectron study of niobium carbide radical

    SciTech Connect

    Luo, Zhihong; Huang, Huang; Zhang, Zheng; Chang, Yih-Chung; Ng, C. Y.

    2014-07-14

    By employing the two-color visible (VIS)-ultraviolet (UV) laser photoexcitation scheme and the pulsed field ionization-photoelectron (PFI-PE) detection, we have obtained rovibronically selected and resolved photoelectron spectra for niobium carbide cation (NbC{sup +}). The fully rotationally resolved state-to-state VIS-UV-PFI-PE spectra thus obtained allow the unambiguous assignments of rotational photoionization transitions, indicating that the electronic configuration and term symmetry of NbC{sup +}(X{sup ~}) ground state are …10σ{sup 2} 5π{sup 4} 11σ{sup 2} (X{sup ~1}Σ{sup +}). Furthermore, the rotational analysis of these spectra yields the ionization energy of NbC [IE(NbC)] to be 56 369.2 ± 0.8 cm{sup −1} (6.9889 ± 0.0001 eV) and the rotation constant B{sub 0}{sup +} = 0.5681 ± 0.0007 cm{sup −1}. The latter value allows the determination of the bond distance r{sub 0}{sup +} = 1.671 ± 0.001 Å for NbC{sup +}(X{sup ~1}Σ{sup +}). Based on conservation of energy, the IE(NbC) determined in the present study along with the known IE(Nb) gives the difference of 0 K bond dissociation energies (D{sub 0}’s) for NbC{sup +} and NbC, D{sub 0}(NbC{sup +}) − D{sub 0}(NbC) = −1855.4 ± 0.9 cm{sup −1} (−0.2300 ± 0.0001 eV). The energetic values and the B{sub 0}{sup +} constant determined in this work are valuable for benchmarking state-of-the-art ab initio quantum calculations of 4d transition metal-containing molecules.

  12. Microwave lens effect for the J = 0 rotational state of CH3CN

    NASA Astrophysics Data System (ADS)

    Spieler, Steffen; Zhong, Wei; Djuricanin, Pavle; Nourbakhsh, Omid; Gerhardt, Ilja; Enomoto, Katsunari; Stienkemeier, Frank; Momose, Takamasa

    2013-07-01

    We demonstrate the manipulation of the translational motion of a polar molecule in its J = 0 rotational ground state by the microwave (MW) dipole force combined with a counter-rotating nozzle. A cold molecular beam of CH3CN seeded in Kr with a longitudinal velocity of about 100 m s-1 was created by a pulsed counter-rotating nozzle. The cold beam was then introduced into a cylindrical MW cavity, in which a standing wave, TM01p mode MW field, nearly resonant to the |J, K> = |1, 0> ← |0, 0> rotational transition of CH3CN was created. By choosing an appropriate MW frequency, we successfully observed focusing and deflection of the cold beam of CH3CN due to the lens effect of the MW standing wave. The present result indicates that the combination of a counter-rotating nozzle and an MW cavity will be a versatile method for making cold and ultracold ensembles of various polar molecules in their rotational ground state.

  13. Rigid rotators. [deriving the time-independent energy states associated with rotational motions of the molecule

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The two-particle, steady-state Schroedinger equation is transformed to center of mass and internuclear distance vector coordinates, leading to the free particle wave equation for the kinetic energy motion of the molecule and a decoupled wave equation for a single particle of reduced mass moving in a spherical potential field. The latter describes the vibrational and rotational energy modes of the diatomic molecule. For fixed internuclear distance, this becomes the equation of rigid rotator motion. The classical partition function for the rotator is derived and compared with the quantum expression. Molecular symmetry effects are developed from the generalized Pauli principle that the steady-state wave function of any system of fundamental particles must be antisymmetric. Nuclear spin and spin quantum functions are introduced and ortho- and para-states of rotators, along with their degeneracies, are defined. Effects of nuclear spin on entropy are deduced. Next, rigid polyatomic rotators are considered and the partition function for this case is derived. The patterns of rotational energy levels for nonlinear molecules are discussed for the spherical symmetric top, for the prolate symmetric top, for the oblate symmetric top, and for the asymmetric top. Finally, the equilibrium energy and specific heat of rigid rotators are derived.

  14. Rotational state detection of electrically trapped polyatomic molecules

    NASA Astrophysics Data System (ADS)

    Glöckner, Rosa; Prehn, Alexander; Rempe, Gerhard; Zeppenfeld, Martin

    2015-05-01

    Detecting the internal state of polar molecules is a substantial challenge when standard techniques such as resonance-enhanced multiphoton ionization or laser-induced fluorescense do not work. As this is the case for most polyatomic molecule species, in this paper we investigate an alternative based on state-selective removal of molecules from an electrically trapped ensemble. Specifically, we deplete molecules by driving rotational and/or vibrational transitions to untrapped states. Fully resolving the rotational state with this method can be a considerable challenge, as the frequency differences between various transitions are easily substantially less than the Stark broadening in an electric trap. However, by using a unique trap design that provides homogeneous fields in a large fraction of the trap volume, we successfully discriminate all rotational quantum numbers, including the rotational M-substate.

  15. Ground beetle (Coleoptera: Carabidae) assemblages in conventional and diversified crop rotation systems.

    PubMed

    O'Rourke, Megan E; Liebman, Matt; Rice, Marlin E

    2008-02-01

    Ground beetles (Coleoptera: Carabidae) are important in agro-ecosystems as generalist predators of invertebrate pests and weed seeds and as prey for larger animals. However, it is not well understood how cropping systems affect ground beetles. Over a 2-yr period, carabids were monitored two times per month using pitfall traps in a conventional chemical input, 2-yr, corn/soybean rotation system and a low input, 4-yr, corn/soybean/triticale-alfalfa/alfalfa rotation system. Carabid assemblages were largely dominated by a few species across all cropping treatments with Poecilus chalcites Say comprising >70% of pitfall catches in both years of study. Overall carabid activity density and species richness were higher in the low input, 4-yr rotation compared with the conventionally managed, 2-yr rotation. There were greater differences in the temporal activity density and species richness of carabids among crops than within corn and soybean treatments managed with different agrichemical inputs and soil disturbance regimes. Detrended correspondence analysis showed strong yearly variation in carabid assemblages in all cropping treatments. The increase in carabid activity density and species richness observed in the 4-yr crop rotation highlights the potential benefits of diverse crop habitats for carabids and the possibility for managing natural enemies by manipulating crop rotations.

  16. The Millimeter-Wave Spectrum of Methacrolein. Torsion-Rotation Effects in the Excited States

    NASA Astrophysics Data System (ADS)

    Zakharenko, Olena; Motiyenko, R. A.; Aviles Moreno, Juan-Ramon; Huet, T. R.

    2015-06-01

    Last year we reported the analysis of the rotational spectrum of s-trans conformer of methacrolein CH2=C(CH3)CHO in the ground vibrational state. In this talk we report the study of its low lying excited vibrational states. The study is based on room-temperature absorption spectra of methacrolein recorded in the frequency range 150 - 465 GHz using the spectrometer in Lille. The new results include assignment of the first excited torsional state (131 cm-1), and the joint analysis of the vt = 0 and vt = 1 states, that allowed us to improve the model in the frame of Rho-Axis-Method (RAM) Hamiltonian and to remove some strong correlations between parameters. Also we assigned the first excited vibrational state of the skeletal torsion mode (170 cm-1). The inverse sequence of A and E tunneling substates as well as anomalous A-E splittings observed for the rotational lines of vsk = 1 state clearly indicate a coupling between methyl torsion and skeletal torsion. However we were able to fit within experimental accuracy the rotational lines of vsk = 1 state using the RAM Hamiltonian. Because of the inversion of the A and E tunneling substates the rotational lines of the vsk = 1 states were assumed to belong to a virtual first excited torsional state. Finally, we assigned several low-Ka rotational transitions of the excited vibrational states above 200 cm-1 but their analysis is complicated by different rotation-vibration interactions. In particular there is an evidence of the Fermi-type resonance between the second excited torsional state and the first excited state of the in-plane skeletal bending mode (265 cm-1). Support from the French Laboratoire d'Excellence CaPPA (Chemical and Physical Properties of the Atmosphere) through contract ANR-10-LABX-0005 of the Programme d'Investissements d'Avenir is acknowledged. Zakharenko O. et al., 69th ISMS, 2014, TI01

  17. Rotationally Inelastic Scattering of Quantum-State-Selected ND3 with Ar.

    PubMed

    Tkáč, Ondřej; Saha, Ashim K; Loreau, Jérôme; Parker, David H; van der Avoird, Ad; Orr-Ewing, Andrew J

    2015-06-11

    Rotationally inelastic scattering of ND3 with Ar is studied at mean collision energies of 410 and 310 cm(–1). In the experimental component of the study, ND3 molecules are prepared by supersonic expansion and subsequent hexapole state selection in the ground electronic and vibrational levels and in the jk(±) = 1(1) rotational level. A beam of state-selected ND3 molecules is crossed with a beam of Ar, and scattered ND3 molecules are detected in single final j′k′(±) quantum states using resonance enhanced multiphoton ionization spectroscopy. State-to-state differential cross sections for rotational-level changing collisions are obtained by velocity map imaging. The experimental measurements are compared with close-coupling quantum-mechanical scattering calculations performed using an ab initio potential energy surface. The computed DCSs agree well with the experimental measurements, confirming the high quality of the potential energy surface. The angular distributions are dominated by forward scattering for all measured final rotational and vibrational inversion symmetry states. This outcome is in contrast to our recent results for inelastic scattering of ND3 with He, where we observed significant amount of sideways and backward scattering for some final rotational levels of ND3. The differences between He and Ar collision partners are explained by differences in the potential energy surfaces that govern the scattering dynamics.

  18. Ground-state structures of Hafnium clusters

    SciTech Connect

    Ng, Wei Chun; Yoon, Tiem Leong; Lim, Thong Leng

    2015-04-24

    Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the ground-state structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-energy structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the ground-state.

  19. The Ground and First Excited Torsional States of Acetic Acid.

    PubMed

    Ilyushin, V. V.; Alekseev, E. A.; Dyubko, S. F.; Podnos, S. V.; Kleiner, I.; Margulès, L.; Wlodarczak, G.; Demaison, J.; Cosléou, J.; Maté, B.; Karyakin, E. N.; Golubiatnikov, G. Yu.; Fraser, G. T.; Suenram, R. D.; Hougen, J. T.

    2001-02-01

    A global fit of microwave and millimeter-wave rotational transitions in the ground and first excited torsional states (v(t) = 0 and 1) of acetic acid (CH(3)COOH) is reported, which combines older measurements from the literature with new measurements from Kharkov, Lille, and NIST. The fit uses a model developed initially for acetaldehyde and methanol-type internal rotor molecules. It requires 34 parameters to achieve a unitless weighted standard deviation of 0.84 for a total of 2518 data and includes A- and E-species transitions with J

  20. Thermodynamic ground states of platinum metal nitrides

    SciTech Connect

    Aberg, D; Sadigh, B; Crowhurst, J; Goncharov, A

    2007-10-09

    We have systematically studied the thermodynamic stabilities of various phases of the nitrides of the platinum metal elements using density functional theory. We show that for the nitrides of Rh, Pd, Ir and Pt two new crystal structures, in which the metal ions occupy simple tetragonal lattice sites, have lower formation enthalpies at ambient conditions than any previously proposed structures. The region of stability can extend up to 17 GPa for PtN{sub 2}. Furthermore, we show that according to calculations using the local density approximation, these new compounds are also thermodynamically stable at ambient pressure and thus may be the ground state phases for these materials. We further discuss the fact that the local density and generalized gradient approximations predict different values of the absolute formation enthalpies as well different relative stabilities between simple tetragonal and the pyrite or marcasite structures.

  1. Ground state of high-density matter

    NASA Technical Reports Server (NTRS)

    Copeland, ED; Kolb, Edward W.; Lee, Kimyeong

    1988-01-01

    It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.

  2. Ground state energy of N Frenkel excitons

    NASA Astrophysics Data System (ADS)

    Pogosov, W.; Combescot, M.

    2009-03-01

    By using the composite many-body theory for Frenkel excitons we have recently developed, we here derive the ground state energy of N Frenkel excitons in the Born approximation through the Hamiltonian mean value in a state made of N identical Q = 0 excitons. While this quantity reads as a density expansion in the case of Wannier excitons, due to many-body effects induced by fermion exchanges between N composite particles, we show that the Hamiltonian mean value for N Frenkel excitons only contains a first order term in density, just as for elementary bosons. Such a simple result comes from a subtle balance, difficult to guess a priori, between fermion exchanges for two or more Frenkel excitons appearing in Coulomb term and the ones appearing in the N exciton normalization factor - the cancellation being exact within terms in 1/Ns where Ns is the number of atomic sites in the sample. This result could make us naively believe that, due to the tight binding approximation on which Frenkel excitons are based, these excitons are just bare elementary bosons while their composite nature definitely appears at various stages in the precise calculation of the Hamiltonian mean value.

  3. On the Stable Ground State of Mackinawite

    NASA Astrophysics Data System (ADS)

    Kwon, K.; Refson, K.; Sposito, G.

    2009-12-01

    Mackinawite is a layer type iron monosulfide (FeS) with stacked sheets of edge-sharing FeS4 tetrahedra. An important player in iron and sulfur cycles, mackinawite is one of the first-formed metastable iron sulfides in anoxic environments, transforming into greigite (Fe3S4) and pyrite (FeS2) minerals or elemental sulfur (S0) and iron (Fe0) depending on redox conditions. Mackinawite also affects the mobility and oxidation states of toxic metals such as As, Hg, and Se. The mineral, typically found as a nanoparticle, has been characterized experimentally. Its fundamental conducting and magnetic properties, however, are still controversial; e.g., whether mackinawite is metallic and whether it has magnetic order. Mackinawite is believed to be metallic and without magnetic ordering down at 4 K based on Mössbauer spectroscopy studies. We examined these two issues by applying plane-wave density functional theory (DFT) to FeS geometry optimization under different magnetic orderings. We found that antiferromagnetic ordering among the Fe atoms is the stable ground state of mackinawite. In this presentation, we shall discuss this result and how it relates to previous experimental work.

  4. Strangeness in the baryon ground states

    NASA Astrophysics Data System (ADS)

    Semke, A.; Lutz, M. F. M.

    2012-10-01

    We compute the strangeness content of the baryon octet and decuplet states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-Nc sum rule estimates of the counter terms relevant for the baryon masses at N3LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. From a global fit we determine the axial coupling constants F ≃ 0.45 and D ≃ 0.80 in agreement with their values extracted from semi-leptonic decays of the baryons. Moreover, various flavor symmetric limits of baron octet and decuplet masses as obtained by the QCDSF-UKQCD group are recovered. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.

  5. Rotational State Microwave Mixing for Laser Cooling of Complex Diatomic Molecules

    NASA Astrophysics Data System (ADS)

    Yeo, Mark; Hummon, Matthew T.; Collopy, Alejandra L.; Yan, Bo; Hemmerling, Boerge; Chae, Eunmi; Doyle, John M.; Ye, Jun

    2015-06-01

    We demonstrate the mixing of rotational states in the ground electronic state using microwave radiation to enhance optical cycling in the molecule yttrium (II) monoxide (YO). This mixing technique is used in conjunction with a frequency modulated and chirped continuous wave laser to slow longitudinally a cryogenic buffer-gas beam of YO. We generate a flux of YO below 10 m /s , directly loadable into a three-dimensional magneto-optical trap. This technique opens the door for laser cooling of diatomic molecules with more complex loss channels due to intermediate states.

  6. Is the ground state of Yang-Mills theory Coulombic?

    SciTech Connect

    Heinzl, T.; Ilderton, A.; Langfeld, K.; Lavelle, M.; McMullan, D.; Lutz, W.

    2008-08-01

    We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-Abelian Coulomb fields is found to have a good overlap with the ground state for all charge separations. In fact, the overlap increases as the lattice regulator is removed. This opens up the possibility that the Coulomb state is the true ground state in the continuum limit.

  7. Rotational and neutron-hole states in {sup 43}S via the neutron knockout and fragmentation reactions

    SciTech Connect

    Riley, L. A.; Hosier, K. E.; Adrich, P.; Baugher, T. R.; Bazin, D.; Diget, C. A.; Weisshaar, D.; Brown, B. A.; Cook, J. M.; Gade, A.; Garland, D. A.; Glasmacher, T.; Ratkiewicz, A.; Siwek, K. P.; Cottle, P. D.; Kemper, K. W.; Tostevin, J. A.

    2009-09-15

    The recent assertion that shape coexistence occurs in the neutron-rich isotope {sup 43}S implies that a state observed at 940 keV in a previous study is a rotational excitation of the deformed ground state. Here we use results from two intermediate-energy reactions to demonstrate that this state--assigned an energy of 971 keV in the present work--is indeed a rotational state. This result strengthens the case for shape coexistence in {sup 43}S.

  8. An efficient magic state approach to small angle rotations

    NASA Astrophysics Data System (ADS)

    Campbell, Earl T.; O'Gorman, Joe

    2016-12-01

    Standard error-correction techniques only provide a quantum memory and need extra gadgets to perform computation. Central to quantum algorithms are small angle rotations, which can be fault-tolerantly implemented given a supply of an unconventional species of magic state. We present a low-cost distillation routine for preparing these small angle magic states. Our protocol builds on the work of Duclos-Cianci and Poulin (2015 Phys. Rev. A 91 042315) by compressing their circuit. Additionally, we present a method of diluting magic states that reduces costs associated with very small angle rotations. We quantify performance by the expected number of noisy magic states consumed per rotation, and compare with other protocols. For modest-sized angles, our protocols offer a factor 24 improvement over the best-known gate synthesis protocols and a factor 2 over the Duclos-Cianci and Poulin protocol. For very small angle rotations, the dilution protocol dramatically reduces costs, giving several orders magnitude improvement over competitors. There also exists an intermediary regime of small, but not very small, angles where our approach gives a marginal improvement over gate synthesis. We discuss how different performance metrics may alter these conclusions.

  9. Rotational and rotationless states of weakly bound molecules

    SciTech Connect

    Lemeshko, Mikhail; Friedrich, Bretislav

    2009-05-15

    By making use of the quantization rule of Raab and Friedrich [Phys. Rev. A 78, 022707 (2008)], we derive simple and accurate formulae for the number of rotational states supported by a weakly bound vibrational level of a diatomic molecule and the rotational constants of any such levels up to the threshold, and provide a criterion for determining whether a given weakly bound vibrational level is rotationless. The results depend solely on the long-range part of the molecular potential and are applicable to halo molecules.

  10. Rotation-vibration states of H3+ at dissociation

    NASA Astrophysics Data System (ADS)

    Kostin, Maxim A.; Polyansky, Oleg L.; Tennyson, Jonathan; Mussa, Hamse Y.

    2003-02-01

    Calculations are presented which estimate energies for all the bound rotation-vibration energy levels of H3+ with rotation angular momentum J=0, 2 and 8. The calculations, which use Radau coordinates with z-axis of the molecule embedded perpendicular to the molecular plane, are performed on 128 nodes of a massively parallel computer. It is found that convergence with respect to basis set size of the higher J states is fairly slow and that further improvements are beyond the capabilities of the current computational set-up.

  11. Probabilistic rotational state preparation of a single molecular ion though consecutive partial projection measurements

    NASA Astrophysics Data System (ADS)

    Drewsen, Michael

    2016-05-01

    Fully quantum state prepared molecular ions are of interest for a wide range of research fields, including ultra-cold chemistry, ultra-high resolution spectroscopy for test of fundamental physics, and quantum information science. Cooling of the translational degrees of freedom of trapped molecular ions into the millikelvin range has become routine through Coulomb interactions with simultaneously trapped and Doppler laser-cooled atomic ions, and recently it has even become possible to prepare a single molecular ion in its absolute ground state with respect to its quantized motion in the external trapping potential. With respect to the internal rovibrational degrees of freedom, significant progress towards single quantum state preparation has as well recently been realized by a series of complementary methods. In the talk, a novel method for probabilistic rotational state preparation of polar molecular ions based on consecutive partial projection measurements will be discussed. Results of state preparation of vibrational cold single MgH+ ions in the rotational ground or first excited state with maximum likelihood estimated populations of 0.98 and 0.95, respectively, will be presented.

  12. On the ground state of Yang-Mills theory

    SciTech Connect

    Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

    2011-08-15

    Highlights: > The ground state overlap for sets of meson potential trial states is measured. > Non-uniform gluonic distributions are probed via Wilson loop operator. > The locally UV-regulated flux-tube operators can optimize the ground state overlap. - Abstract: We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

  13. Ground based studies of the vibrational and rotational dynamics of acoustically levitated drops and shells

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Leung, E.

    1990-01-01

    A substantial amount of experimental data can be gathered on the dynamics of acoustically positioned liquids in a ground-based laboratory and during short duration low-gravity parabolic flights of the KC-135. The preliminary results of a set of measurements of the static shape, of the vibrational spectrum, and the rotation equilibrium shapes of simple drops and liquid shells carried out using ultrasonic levitators working between 19 and 40 kHz is presented. The droplet diameter ranges between 1 and 5 mm, the surface tension of the liquid used varies between 25 and 70 dynes/cm, and the viscosity is changed between 1 to 1,000 cP. Of particular interest is the variation of the frequency of the fundamental mode of shape oscillation with various factors, and the effects of static drop shape deformation on the limit of stability of the axisymmetric shape of a drop in solid-body rotation.

  14. Enhanced optical cycling and slowing of YO through rotational state microwave mixing

    NASA Astrophysics Data System (ADS)

    Yan, Bo; Hummon, Matthew; Yeo, Mark; Collopy, Alejandra; Hemmerling, Boerge; Chae, Eunmi; Anderegg, Loic; Ravi, Aakash; Doyle, John; Ye, Jun

    2015-05-01

    In order to address rotational dark states in the molecule yttrium (II) monoxide (YO) and to enhance optical cycling, we demonstrate the remixing of ground electronic state rotational levels using microwave radiation. This mixing technique, in conjunction with a broadband modulated and frequency chirped laser, is used to decelerate a beam of YO from a cryogenic buffer gas cell. The result is a population of molecules with velocities less than 10 m/s, which are sufficiently slow to be loaded into a magneto-optical trap. With two vibrational repump lasers, the cycling transition is closed to the 10-6 level. Additionally, we present progress towards a three dimensional implementation of a magneto-optical trap for YO. This work was supported in part by the Gordon and Betty Moore Foundation through Grant GBMF3852. We also acknowledge support from ARO, AFOSR (MURI), NIST, and NSF.

  15. Infrared spectroscopy of molecular ions in selected rotational and spin-orbit states

    NASA Astrophysics Data System (ADS)

    Jacovella, U.; Agner, J. A.; Schmutz, H.; Deiglmayr, J.; Merkt, F.

    2016-07-01

    First results are presented obtained with an experimental setup developed to record IR spectra of rotationally state-selected ions. The method we use is a state-selective version of a method developed by Schlemmer et al. [Int. J. Mass Spectrom. 185, 589 (1999); J. Chem. Phys. 117, 2068 (2002)] to record IR spectra of ions. Ions are produced in specific rotational levels using mass-analyzed-threshold-ionization spectroscopy. The state-selected ions generated by pulsed-field ionization of Rydberg states of high principal quantum number (n ≈ 200) are extracted toward an octupole ion guide containing a neutral target gas. Prior to entering the octupole, the ions are excited by an IR laser. The target gas is chosen so that only excited ions react to form product ions. These product ions are detected mass selectively as a function of the IR laser wavenumber. To illustrate this method, we present IR spectra of C 2 H2 + in selected rotational levels of the 2Πu,3/2 and 2Πu,1/2 spin-orbit components of the vibronic ground state.

  16. Ground state configurations in two-mode quantum Rabi models

    NASA Astrophysics Data System (ADS)

    Chilingaryan, Suren; Rodríguez-Lara, B. M.

    We study two models describing a single two-level system coupled to two boson field modes in either a parallel or orthogonal configuration. Both models may be feasible for experimental realization through Raman adiabatic driving in cavity QED. We study their ground state configurations; that is, we find the quantum precursors of the corresponding semi-classical phase transitions. We found that the ground state configurations of both models present the same critical coupling as the quantum Rabi model. Around this critical coupling, the ground state goes from the so-called normal configuration with no excitation, the qubit in the ground state and the fields in the quantum vacuum state, to a ground state with excitations, the qubit in a superposition of ground and excited state, while the fields are not in the vacuum anymore, for the first model. The second model shows a more complex ground state configuration landscape where we find the normal configuration mentioned above, two single-mode configurations, where just one of the fields and the qubit are excited, and a dual-mode configuration, where both fields and the qubit are excited. S A Chilingaryan acknowledges financial support from CONACYT.

  17. Design of tailored microwave pulses to create rotational coherent states for an asymmetric-top molecule

    NASA Astrophysics Data System (ADS)

    Ortigoso, Juan

    1998-06-01

    Tailored microwave pulses, to guide asymmetric-top molecules from selected rotational states belonging to the vibronic ground state to generalized angular-momentum coherent states, are designed by using optimal control theory. Characteristics that the molecules have to fulfill in order to achieve the goal with feasible pulses are discussed. Properties of the pulses are discussed as well. The further dephasing among the components of the wave packet which, for the simplest coherent state, is a form of dynamical tunneling, can be locked by exploiting the changes that energy levels and eigenfunctions undergo in the presence of an external static electric field with appropriate intensity. For the special case with M=0, periodic fields are more flexible in avoiding dephasing. This is shown by examining properties of quasienergies and dressed states resulting from the diagonalization of a truncated Floquet matrix.

  18. Parafermionic states in rotating Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Regnault, N.; Jolicoeur, Th.

    2007-12-01

    We investigate some properties of the parafermionic states, which may occur in rapidly rotating ultracold bosonic atomic gases at lowest Landau level filling factor ν=k/2 (with k integer ⩾2 ). These states have manifolds of quasihole states, which are expected to display non-Abelian statistics. We use exact diagonalizations in the spherical geometry to investigate the quasihole manifolds for quantum Hall states at ν=1 , 3/2 , 2, and 5/2 . We show that there is a perfect agreement between numerical findings and the prediction of conformal field theory concerning the number of orbital angular momentum multiplets as a function of added vorticity. The overlap between quasihole candidate wave functions and the corresponding states for realistic delta function interactions between bosons is computed. This allows us to discuss the possible relevance of non-Abelian degeneracy in the physical situation of ultracold atoms.

  19. Ground state energy fluctuations in the nuclear shell model

    NASA Astrophysics Data System (ADS)

    Velázquez, Víctor; Hirsch, Jorge G.; Frank, Alejandro; Barea, José; Zuker, Andrés P.

    2005-05-01

    Statistical fluctuations of the nuclear ground state energies are estimated using shell model calculations in which particles in the valence shells interact through well-defined forces, and are coupled to an upper shell governed by random 2-body interactions. Induced ground-state energy fluctuations are found to be one order of magnitude smaller than those previously associated with chaotic components, in close agreement with independent perturbative estimates based on the spreading widths of excited states.

  20. Rotational Energy Transfer in Metastable States of Heteronuclear Molecules

    DTIC Science & Technology

    1989-01-01

    developed by Polanyi and Woodall1 1 in their studies of HF(v) relaxation and has been applied to a number of other species. Pritchard and co-workers 12 ,13...Chemiluminescence from the3 F + 12F Reaction," J. Chem. Phys. 74, 6508 (1981). 8. Clyne, Michael A.A. and McDermid, I. Stuart, "B3 H(0+ ) States of IF, ICI, and...State of ICI," 1984. 11. Polanyi , J.E. and Woodall, K.B., "Mechanisms of Rotational Relaxation," J. Chem. Phys. 56, 1563 (1972). 12. Pritchard, D.E

  1. Infrared Spectroscopy of Ions in Selected Rotational and Spin-Orbit States

    NASA Astrophysics Data System (ADS)

    Jacovella, Ugo; Agner, Josef A.; Schmutz, Hansjürg; Merkt, Frederic

    2016-06-01

    First results are presented obtained using an experimental setup developed to record IR spectra of rotationally state-selected ions. The method we use is a state-selective version of a method developed by Schlemmer et al. to record IR spectra of ions. Ions are produced in specific rotational levels using mass-analysed threshold ionisation (MATI) spectroscopy combined with single-photon excitation of neutral molecules in supersonic expansions with a vacuum-ultraviolet laser. The ions generated by pulsed-field ionisation of Rydberg states of high principal quantum number (n ≈ 200) are extracted toward an octupole ion guide containing a neutral target gas. Prior to entering the octupole the ions are excited by an IR laser. The target gas is chosen so that only excited ions react to form product ions. These product ions are detected mass selectively as function of the IR laser wavenumber. To illustrate this method, we present IR spectra of C_2H_2^+ in selected rotational levels of the ^2Π3/2 and ^2Π1/2 spin-orbit components of the electronic ground state. Schlemmer et al., J. Chem. Phys. 117, 2068 (2002)

  2. Handbook for state ground water managers

    SciTech Connect

    Not Available

    1992-05-01

    ;Table of Contents: Nonpoint Source Implementation; State Public Water System Supervision; State Underground Water Source Protection (Underground Injection Control); Water Pollution Control -- State and Interstate Program Support (106 Grants); Water Quality Management Planning; Agriculture in Concert with the Environment; Consolidated Pesticide Compliance Monitoring and Program Cooperative Agreements; Pollution Prevention Incentives for States; Hazardous Substance Response Trust Fund; Hazardous Waste Financial Assistance; Underground Storage Tank Program; Leaking Underground Storage Tank Trust Fund; State/EPA Data Management Financial Assistance Program; Environmental Education; and Multi-Media Assistance Agreements for Indian Tribes.

  3. Analysis of ground state in random bipartite matching

    NASA Astrophysics Data System (ADS)

    Shi, Gui-Yuan; Kong, Yi-Xiu; Liao, Hao; Zhang, Yi-Cheng

    2016-02-01

    Bipartite matching problems emerge in many human social phenomena. In this paper, we study the ground state of the Gale-Shapley model, which is the most popular bipartite matching model. We apply the Kuhn-Munkres algorithm to compute the numerical ground state of the model. For the first time, we obtain the number of blocking pairs which is a measure of the system instability. We also show that the number of blocking pairs formed by each person follows a geometric distribution. Furthermore, we study how the connectivity in the bipartite matching problems influences the instability of the ground state.

  4. Evaluation of fault-normal/fault-parallel directions rotated ground motions for response history analysis of an instrumented six-story building

    USGS Publications Warehouse

    Kalkan, Erol; Kwong, Neal S.

    2012-01-01

    According to regulatory building codes in United States (for example, 2010 California Building Code), at least two horizontal ground-motion components are required for three-dimensional (3D) response history analysis (RHA) of buildings. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHA analyses should be performed separately (when FN and then FP are aligned with the transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all nonredundant rotation angles. This assumption is examined here using a 3D computer model of a six-story reinforced-concrete instrumented building subjected to an ensemble of bidirectional near-fault ground motions. Peak responses of engineering demand parameters (EDPs) were obtained for rotation angles ranging from 0° through 180° for evaluating the FN/FP directions. It is demonstrated that rotating ground motions to FN/FP directions (1) does not always lead to the maximum responses over all angles, (2) does not always envelope the range of possible responses, and (3) does not provide maximum responses for all EDPs simultaneously even if it provides a maximum response for a specific EDP.

  5. Inversion of ground-motion data from a seismometer array for rotation using a modification of Jaeger's method

    USGS Publications Warehouse

    Chi, W.-C.; Lee, W.H.K.; Aston, J.A.D.; Lin, C.J.; Liu, C.-C.

    2011-01-01

    We develop a new way to invert 2D translational waveforms using Jaeger's (1969) formula to derive rotational ground motions about one axis and estimate the errors in them using techniques from statistical multivariate analysis. This procedure can be used to derive rotational ground motions and strains using arrayed translational data, thus providing an efficient way to calibrate the performance of rotational sensors. This approach does not require a priori information about the noise level of the translational data and elastic properties of the media. This new procedure also provides estimates of the standard deviations of the derived rotations and strains. In this study, we validated this code using synthetic translational waveforms from a seismic array. The results after the inversion of the synthetics for rotations were almost identical with the results derived using a well-tested inversion procedure by Spudich and Fletcher (2009). This new 2D procedure can be applied three times to obtain the full, three-component rotations. Additional modifications can be implemented to the code in the future to study different features of the rotational ground motions and strains induced by the passage of seismic waves.

  6. Antifreeze acceptability for ground-coupled heat pump ground loops in the United States

    SciTech Connect

    Den Braven, K.R.

    1998-10-01

    When designing and installing closed-loop ground-coupled heat pumps systems, it is necessary to be aware of applicable environmental regulations. Within the United States, nearly half of the states have regulations specifying or restricting the use of particular antifreezes or other fluids within the ground loop of a ground-coupled heat pump system. A number of other states have regulations pending. While all of these regulations are based on the need to preserve groundwater and/or aquifer quality, the list of acceptable antifreezes varies among those states with specified fluids. Typical antifreezes in use include ethylene glycol, propylene glycol, brines, alcohols, and potassium acetate. Each of these has its benefits and drawbacks. The status of the regulations has been determined for all of the states. An overview of the regulations is presented in this paper, along with a summary of the states` concerns.

  7. The Rotation State of Comet 103P/Hartley 2

    NASA Astrophysics Data System (ADS)

    Farnham, Tony; Knight, Matthew M.; Schleicher, David G.

    2016-10-01

    On November 4, 2010, the Deep Impact (DI) spacecraft made its closest approach to comet 103P/Hartley 2, passing only 694 km from the nucleus. Observations of the coma produced a lightcurve that shows the nucleus is in a state of non-principal axis rotation that evolves with time, while other observations revealed a nucleus that has concentrated collimated jets driven by CO2 emission (A'Hearn et al., 2011), large variability in the production of H2O and CO2 (Besse et al. 2016), and ice patches on the surface (Sunshine et al. 2011). To properly interpret the significance of these phenomena, it is necessary to understand the rotation of the nucleus, so that its thermal history can be derived and properly modeled, while at the same time, it is likely that the comet's high activity levels play an important role in the nucleus dynamics.An analysis of the lightcurve by Belton et al (2013) described the comet's rotation state, with two periodicities (primary of 18 h, secondary of 28 or 55 h) that change with time. Although their solution describes the periodicities observed around closest approach, it is insufficient to reproduce the changes in coma morphology with time. We are performing an analysis of the structures in the coma (Farnham 2009), using Monte Carlo routines to model the outflowing dust produced by active sources on the nucleus, to derive a comprehensive solution for the nucleus' rotation.We are also obtaining new observations of Hartley 2 in June/July 2016 (r~3.2 AU) to measure the nucleus' primary component period before the comet becomes highly active. This will provide an end-state measure of the rotation from the 2010 apparition, as well as a starting value for the current apparition, to allow its continuing evolution to be monitored. We will present an update on the status and preliminary results of these analyses.This work is funded by NASA Grant NNX12AQ64G.A'Hearn, M.F., et al. (2011) Science 332, 1396-1400Belton M.J.S., et al. (2013) Icarus 222, 595

  8. Toward Rotational State-Selective Photoionization of ThF+ Ions

    NASA Astrophysics Data System (ADS)

    Zhou, Yan; Ng, Kia Boon; Gresh, Dan; Cairncross, William; Grau, Matt; Ni, Yiqi; Cornell, Eric; Ye, Jun

    2016-06-01

    ThF+ has been chosen to replace HfF+ for a second-generation measurement of the electric dipole moment of the electron (eEDM). Compared to the currently running HfF+ eEDM experiment, ThF+ has several advantages: (i) the eEDM-sensitive state (3Δ1) is the ground state, which facilitates a long coherence time [1]; (ii) its effective electric field (35 GV/cm) is 50% larger than that of HfF+, which promises a direct increase of the eEDM sensitivity [2]; and (iii) the ionization energy of neutral ThF is lower than its dissociation energy, which introduces greater flexibility in rotational state-selective photoionization via core-nonpenetrating Rydberg states [3]. In this talk, we first present our strategy of preparing and utilizing core-nonpenetrating Rydberg states for rotational state-selective ionization. Then, we report spectroscopic data of laser-induced fluorescence of neutral ThF, which provides critical information for multi-photon ionization spectroscopy. [1] D. N. Gresh, K. C. Cossel, Y. Zhou, J. Ye, E. A. Cornell, Journal of Molecular Spectroscopy, 319 (2016), 1-9 [2] M. Denis, M. S. Nørby, H. J. A. Jensen, A. S. P. Gomes, M. K. Nayak, S. Knecht, T. Fleig, New Journal of Physics, 17 (2015) 043005. [3] Z. J. Jakubek, R. W. Field, Journal of Molecular Spectroscopy 205 (2001) 197-220.

  9. Theory of ground state factorization in quantum cooperative systems.

    PubMed

    Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio

    2008-05-16

    We introduce a general analytic approach to the study of factorization points and factorized ground states in quantum cooperative systems. The method allows us to determine rigorously the existence, location, and exact form of separable ground states in a large variety of, generally nonexactly solvable, spin models belonging to different universality classes. The theory applies to translationally invariant systems, irrespective of spatial dimensionality, and for spin-spin interactions of arbitrary range.

  10. Ground states of the spin-1 Bose-Hubbard model.

    PubMed

    Katsura, Hosho; Tasaki, Hal

    2013-03-29

    We prove basic theorems about the ground states of the S=1 Bose-Hubbard model. The results are quite universal and depend only on the coefficient U2 of the spin-dependent interaction. We show that the ground state exhibits saturated ferromagnetism if U2<0, is spin-singlet if U2>0, and exhibits "SU(3)-ferromagnetism" if U2=0, and completely determine the degeneracy in each region.

  11. STATE WATER RESOURCES RESEARCH INSTITUTE PROGRAM: GROUND WATER RESEARCH.

    USGS Publications Warehouse

    Burton, James S.; ,

    1985-01-01

    This paper updates a review of the accomplishments of the State Water Resources Research Program in ground water contamination research. The aim is to assess the progress made towards understanding the mechanisms of ground water contamination and based on this understanding, to suggest procedures for the prevention and control of ground water contamination. The following research areas are covered: (1) mechanisms of organic contaminant transport in the subsurface environment; (2) bacterial and viral contamination of ground water from landfills and septic tank systems; (3) fate and persistence of pesticides in the subsurface; (4) leachability and transport of ground water pollutants from coal production and utilization; and (5) pollution of ground water from mineral mining activities.

  12. Ground-based observations of Phoebe (S9) and its rotational dynamics

    NASA Astrophysics Data System (ADS)

    Aleshkina, Ekaterina Yu.; Devyatkin, Alexandr V.; Gorshanov, Denis L.

    Analysis of CCD observations of Phoebe, the 9th satellite of Saturn (visual magnitude of about 16.5), with a mirror astrograph ZA-320M at Pulkovo Observatory in Saint-Petersburg are presented. Photometric observations are performed both in the integral band of the telescope and in bands BVR of the Johnson system. Reference catalogues USNO-A2.0 (for R - filter and integral observations) and Ticho-2 (for V and B - filters) were used. Rotational light-curve data for Phoebe taken over a short time span (2 - 8 hours) for several nights are presented. Numerical investigation of the evolution of Phoebe's rotational dynamics is carried out. The probability of Phoebe's capture in resonant states that are distinct from 1:1 is estimated.

  13. Probable Rotation States of Rocket Bodies in Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Ojakangas, Gregory W.; Anz-Meador, P.; Cowardin, H.

    2012-01-01

    In order for Active Debris Removal to be accomplished, it is critically important to understand the probable rotation states of orbiting, spent rocket bodies. As compared to the question of characterizing small unresolved debris, in this problem there are several advantages: (1) objects are of known size, mass, shape and color, (2) they have typically been in orbit for a known period of time, (3) they are large enough that resolved images may be obtainable for verification of predicted orientation, and (4) the dynamical problem is simplified to first order by largely cylindrical symmetry. It is also nearly certain for realistic rocket bodies that internal friction is appreciable in the case where residual liquid or, to a lesser degree, unconsolidated solid fuels exist. Equations of motion have been developed for this problem in which internal friction as well as torques due to solar radiation, magnetic induction, and gravitational gradient are included. In the case of pure cylindrical symmetry, the results are compared to analytical predictions patterned after the standard approach for analysis of symmetrical tops. This is possible because solar radiation and gravitational torques may be treated as conservative. Agreement between results of both methods ensures their mutual validity. For monotone symmetric cylinders, solar radiation torque vanishes if the center of mass resides at the geometric center of the object. Results indicate that in the absence of solar radiation effects, rotation states tend toward an equilibrium configuration in which rotation is about the axis of maximum inertia, with the axis of minimum inertia directed toward the center of the earth. Solar radiation torque introduces a modification to this orientation. The equilibrium state is asymptotically approached within a characteristic timescale given by a simple ratio of relevant characterizing parameters for the body in question. Light curves are simulated for the expected asymptotic final

  14. Pulsed-field ionization zero electron kinetic energy spectrum of the ground electronic state of BeOBe+.

    PubMed

    Antonov, Ivan O; Barker, Beau J; Heaven, Michael C

    2011-01-28

    The ground electronic state of BeOBe(+) was probed using the pulsed-field ionization zero electron kinetic energy photoelectron technique. Spectra were rotationally resolved and transitions to the zero-point level, the symmetric stretch fundamental and first two bending vibrational levels were observed. The rotational state symmetry selection rules confirm that the ground electronic state of the cation is (2)Σ(g)(+). Detachment of an electron from the HOMO of neutral BeOBe results in little change in the vibrational or rotational constants, indicating that this orbital is nonbonding in nature. The ionization energy of BeOBe [65480(4) cm(-1)] was refined over previous measurements. Results from recent theoretical calculations for BeOBe(+) (multireference configuration interaction) were found to be in good agreement with the experimental data.

  15. The structure of the Hoyle state via a measurement of the 'Hoyle Rotational Band' in 12C

    NASA Astrophysics Data System (ADS)

    Gai, M.; UConn-Yale-TUNL-Weizmann-PTB-UCL Collaboration

    2013-04-01

    We have measured the 12C(γ, 3α) reaction with an Optical Time Projection Chamber (O-TPC) detector operating with the CO2(80%) + N2(20%) gas mixture and gamma-ray beams from the HIγS facility of the TUNL at Duke. We measured complete angular distributions (between 9.1 - 10.7 MeV) from which we determine the cross section yield curve and E1-E2 relative phases leading to an unambiguous identification of the second 2+ state in 12C at 10.03(11) MeV. The observed spectrum of 12C below 12 MeV including the 2+2 observed in this work resembles the rotation-vibration spectrum predicted for a triangular shape oblate spinning top in which the Hoyle state is the first vibrational breathing mode of the triangular three alpha particle system. The predicted rotation-vibration spectrum of a triangular shape oblate spinning top (with a D3h symmetry) allows us to compare the moment of inertia of the predicted Hoyle rotational band to the ground state rotational band and in this way extract the model radius parameter of the Hoyle state of 3.22(8) fm ( time the r.m.s. radius of the ground state) which is close to the radius extracted from 12C(x,x') data.

  16. Estimation of ground state pentaquark masses

    NASA Astrophysics Data System (ADS)

    Xu, K.; Ritjoho, N.; Srisuphaphon, S.; Yan, Y.

    2014-04-01

    Permutation groups are applied to analyze the symmetries of multiquark systems and wave functions of pentaquark states are constructed systematically in the language of Yamanouchi basis. We estimate the mass of baryons in the constituent quark model with one-gluon-exchange interaction, assuming that baryons consist of the q3 component as well as the q4/line q pentaquark component.

  17. Nature of ground and electronic excited states of higher acenes

    PubMed Central

    Yang, Yang; Yang, Weitao

    2016-01-01

    Higher acenes have drawn much attention as promising organic semiconductors with versatile electronic properties. However, the nature of their ground state and electronic excited states is still not fully clear. Their unusual chemical reactivity and instability are the main obstacles for experimental studies, and the potentially prominent diradical character, which might require a multireference description in such large systems, hinders theoretical investigations. Here, we provide a detailed answer with the particle–particle random-phase approximation calculation. The 1Ag ground states of acenes up to decacene are on the closed-shell side of the diradical continuum, whereas the ground state of undecacene and dodecacene tilts more to the open-shell side with a growing polyradical character. The ground state of all acenes has covalent nature with respect to both short and long axes. The lowest triplet state 3B2u is always above the singlet ground state even though the energy gap could be vanishingly small in the polyacene limit. The bright singlet excited state 1B2u is a zwitterionic state to the short axis. The excited 1Ag state gradually switches from a double-excitation state to another zwitterionic state to the short axis, but always keeps its covalent nature to the long axis. An energy crossing between the 1B2u and excited 1Ag states happens between hexacene and heptacene. Further energetic consideration suggests that higher acenes are likely to undergo singlet fission with a low photovoltaic efficiency; however, the efficiency might be improved if a singlet fission into multiple triplets could be achieved. PMID:27528690

  18. Ground-Water Availability in the United States

    USGS Publications Warehouse

    Reilly, Thomas E.; Dennehy, Kevin F.; Alley, William M.; Cunningham, William L.

    2008-01-01

    Ground water is among the Nation's most important natural resources. It provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. Large-scale development of ground-water resources with accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. The challenges in determining ground-water availability are many. This report examines what is known about the Nation's ground-water availability and outlines a program of study by the U.S. Geological Survey Ground-Water Resources Program to improve our understanding of ground-water availability in major aquifers across the Nation. The approach is designed to provide useful regional information for State and local agencies who manage ground-water resources, while providing the building blocks for a national assessment. The report is written for a wide audience interested or involved in the management, protection, and sustainable use of the Nation's water resources.

  19. Mars' rotational state and tidal deformations from radio interferometry of a network of landers.

    NASA Astrophysics Data System (ADS)

    Iess, L.; Giuliani, S.; Dehant, V.

    2012-04-01

    The precise determination of the rotational state of solar system bodies is one of the main tools to investigate their interior structure. Unfortunately the accuracies required for geophysical interpretations are very stringent, and generally unattainable from orbit using optical or radar tracking of surface landmarks. Radio tracking of a lander from ground or from a spacecraft orbiting the planet offers substantial improvements, especially if the lander lifetime is adequately long. The optimal configuration is however attained when two or more landers can be simultaneously tracked from a ground antenna in an interferometric mode. ESA has been considering a network of landers on Mars since many years, and recently this concept has been revived by the study of the Mars Network Science Mission (MNSM). The scientific rationale of MNSM is the investigation of the Mars' interior and atmosphere by means of a network of two or three landers, making it especially suitable for interferometric observations. In order to synthesize an interferometer, the MNSN landers must be tracked simultaneously from a single ground antenna in a coherent two-way mode. The uplink radio signal (at X- or Ka-band) is received by the landers' transponders and retransmitted to ground in the same frequency band. The signals received at ground station are then recorded (typically at few tens of kHz) and beaten against each other to form the output of the interferometer, a complex phasor. The differential phase retain information on Mars' rotational parameters and tidal deformations. A crucial aspect of the interferometric configuration is the rejection of common noise and error sources. Errors in the station location, Earth orientation parameters and ephemerides, path delays due to the Earth troposphere and ionosphere, and, to a good extent, interplanetary plasma are cancelled out. The main residual errors are due to differential path delays from Mars' atmosphere and differential drifts of the

  20. Production of Ultracold, Absolute Vibrational Ground State Sodium-Cesium Molecules

    NASA Astrophysics Data System (ADS)

    Zabawa, Patrick J.

    This dissertation describes a progression of experiments that are based on the association of ultracold (˜250 muK) Na and Cs atoms with laser light. One of the primary goals of the experiment is to form molecules in the absolute vibrational ground state. The work begins with our attempts to label, with certainty, spectral lines obtained from tuning either the photoassociation (PA formation) and Resonance Enhanced Multi-Photon Ionization (REMPI detection) lasers. To this end, we develop a technique that has heretofore never been used in the ultracold molecule community: pulsed depletion spectroscopy (PDS). Traditionally, depletion spectroscopy involves the use of narrow-linewidth CW lasers. However, the narrow linewidth and limited tuning ranges of diodes used for CW depletion spectroscopy mean that this technique is only helpful if the expected transitions are known to some degree in advance, and even then is primarily useful for determining closely-spaced rotational ground state populations. In contrast, the broad linewidth and flexible tuning range of a pulsed dye laser makes it suitable for the detection of vibrational progressions, allowing fast determination of ground state populations even without a priori knowledge of the transitions involved. We also use this technique in our investigation of excited state potential energy curves (PECs). We also investigate a range of PA resonances detuned from the Cs D1 and D2 lines. We find and label PA structure associated with at least 6, and possibly all 8 electronic states corresponding to both of the Cs 6P fine structure asymptotes. From the PA and depletion spectra, we obtain information on the PA scattering process and the excited electronic states. Among the PA spectra, we find several channels which directly form vibrational ground state molecules in the singlet electronic state. Finally, we manipulate the internal states of molecules created with PA using laser light. We use broadband laser sources to pump

  1. Ensemble Theory for Stealthy Hyperuniform Disordered Ground States

    NASA Astrophysics Data System (ADS)

    Torquato, S.; Zhang, G.; Stillinger, F. H.

    2015-04-01

    It has been shown numerically that systems of particles interacting with isotropic "stealthy" bounded long-ranged pair potentials (similar to Friedel oscillations) have classical ground states that are (counterintuitively) disordered, hyperuniform, and highly degenerate. Disordered hyperuniform systems have received attention recently because they are distinguishable exotic states of matter poised between a crystal and liquid that are endowed with novel thermodynamic and physical properties. The task of formulating an ensemble theory that yields analytical predictions for the structural characteristics and other properties of stealthy degenerate ground states in d -dimensional Euclidean space Rd is highly nontrivial because the dimensionality of the configuration space depends on the number density ρ and there is a multitude of ways of sampling the ground-state manifold, each with its own probability measure for finding a particular ground-state configuration. The purpose of this paper is to take some initial steps in this direction. Specifically, we derive general exact relations for thermodynamic properties (energy, pressure, and isothermal compressibility) that apply to any ground-state ensemble as a function of ρ in any d , and we show how disordered degenerate ground states arise as part of the ground-state manifold. We also derive exact integral conditions that both the pair correlation function g2(r ) and structure factor S (k ) must obey for any d . We then specialize our results to the canonical ensemble (in the zero-temperature limit) by exploiting an ansatz that stealthy states behave remarkably like "pseudo"-equilibrium hard-sphere systems in Fourier space. Our theoretical predictions for g2(r ) and S (k ) are in excellent agreement with computer simulations across the first three space dimensions. These results are used to obtain order metrics, local number variance, and nearest-neighbor functions across dimensions. We also derive accurate analytical

  2. Magnetic field induced lattice ground states from holography

    NASA Astrophysics Data System (ADS)

    Bu, Yan-Yan; Erdmenger, Johanna; Shock, Jonathan P.; Strydom, Migael

    2013-03-01

    We study the holographic field theory dual of a probe SU(2) Yang-Mills field in a background (4 + 1)-dimensional asymptotically Anti-de Sitter space. We find a new ground state when a magnetic component of the gauge field is larger than a critical value. The ground state forms a triangular Abrikosov lattice in the spatial directions perpendicular to the magnetic field. The lattice is composed of superconducting vortices induced by the condensation of a charged vector operator. We perform this calculation both at finite temperature and at zero temperature with a hard wall cutoff dual to a confining gauge theory. The study of this state may be of relevance to both holographic condensed matter models as well as to heavy ion physics. The results shown here provide support for the proposal that such a ground state may be found in the QCD vacuum when a large magnetic field is present.

  3. Preliminary solution for the shape and rotational state of the nucleus of comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Lamy, P.; Jorda, L.; Kaasalainen, M.; Hviid, S.; Faury, G.; Toth, I.; Groussin, O.

    2014-07-01

    In preparation of ESA's ROSETTA mission to comet 67P/Churyumov-Gerasimenko, solutions for the shape and rotational state of its nucleus have been published based on observation with the Hubble and Spitzer space telescopes as well as ground-based observations (Lamy et al. 2006, 2007, 2008; Lowry et al. 2012). Following the wake-up of the Rosetta spacecraft in January 2014 and the successful commissioning of the OSIRIS camera system in March, a first lightcurve of the inactive nucleus has been obtained on 23 March 2014 with the OSIRIS Narrow Angle Camera (NAC). Further lightcurves will be acquired in the forthcoming months. We will present an updated solution for the shape and rotational state based on these data sets as of end of June 2014 combined with past Hubble and Spitzer space telescopes as well as ground-based observations using the technique of lightcurve inversion.

  4. Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance

    PubMed Central

    Li, Zhaokai; Yung, Man-Hong; Chen, Hongwei; Lu, Dawei; Whitfield, James D.; Peng, Xinhua; Aspuru-Guzik, Alán; Du, Jiangfeng

    2011-01-01

    Quantum ground-state problems are computationally hard problems for general many-body Hamiltonians; there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the ground state is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the ground state by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the ground-state problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10−5 decimal digit). The ground-state fidelity was distilled to be more than 80%, and the singlet-to-triplet switching near the critical field is reliably captured. This result shows that quantum simulators can better leverage classical trial wave functions than classical computers PMID:22355607

  5. Quench of a symmetry-broken ground state

    NASA Astrophysics Data System (ADS)

    Giampaolo, S. M.; Zonzo, G.

    2017-01-01

    We analyze the problem of how different ground states associated with the same set of Hamiltonian parameters evolve after a sudden quench. To realize our analysis we define a quantitative approach to the local distinguishability between different ground states of a magnetically ordered phase in terms of the trace distance between the reduced density matrices obtained by projecting two ground states in the same subset. Before the quench, regardless of the particular choice of subset, any system in a magnetically ordered phase is characterized by ground states that are locally distinguishable. On the other hand, after the quench, the maximum distinguishability shows an exponential decay in time. Hence, in the limit of very long times, all the information about the particular initial ground state is lost even if the systems are integrable. We prove our claims in the framework of the magnetically ordered phases that characterize both the X Y and the N -cluster Ising models. The fact that we find similar behavior in models within different classes of symmetry makes us confident about the generality of our results.

  6. Should ground-motion records be rotated to fault-normal/parallel or maximum direction for response history analysis of buildings?

    USGS Publications Warehouse

    Reyes, Juan C.; Kalkan, Erol

    2012-01-01

    In the United States, regulatory seismic codes (for example, California Building Code) require at least two sets of horizontal ground-motion components for three-dimensional (3D) response history analysis (RHA) of building structures. For sites within 5 kilometers (3.1 miles) of an active fault, these records should be rotated to fault-normal and fault-parallel (FN/FP) directions, and two RHAs should be performed separately—when FN and then FP direction are aligned with transverse direction of the building axes. This approach is assumed to lead to two sets of responses that envelope the range of possible responses over all nonredundant rotation angles. The validity of this assumption is examined here using 3D computer models of single-story structures having symmetric (torsionally stiff) and asymmetric (torsionally flexible) layouts subjected to an ensemble of near-fault ground motions with and without apparent velocity pulses. In this parametric study, the elastic vibration period is varied from 0.2 to 5 seconds, and yield-strength reduction factors, R, are varied from a value that leads to linear-elastic design to 3 and 5. Further validations are performed using 3D computer models of 9-story structures having symmetric and asymmetric layouts subjected to the same ground-motion set. The influence of the ground-motion rotation angle on several engineering demand parameters (EDPs) is examined in both linear-elastic and nonlinear-inelastic domains to form benchmarks for evaluating the use of the FN/FP directions and also the maximum direction (MD). The MD ground motion is a new definition for horizontal ground motions for use in site-specific ground-motion procedures for seismic design according to provisions of the American Society of Civil Engineers/Seismic Engineering Institute (ASCE/SEI) 7-10. The results of this study have important implications for current practice, suggesting that ground motions rotated to MD or FN/FP directions do not necessarily provide

  7. Ferromagnetic Ground States in Face-Centered Cubic Hubbard Clusters

    PubMed Central

    Souza, T. X. R.; Macedo, C. A.

    2016-01-01

    In this study, the ground state energies of face-centered cubic Hubbard clusters are analyzed using the Lanczos method. Examination of the ground state energy as a function of the number of particle per site n showed an energy minimum for face-centered cubic structures. This energy minimum decreased in n with increasing coulombic interaction parameter U. We found that the ground state energy had a minimum at n = 0.6, when U = 3W, where W denotes the non-interacting energy bandwidth and the face-centered cubic structure was ferromagnetic. These results, when compared with the properties of nickel, shows strong similarity with other finite temperature analyses in the literature and supports the Hirsh’s conjecture that the interatomic direct exchange interaction dominates in driving the system into a ferromagnetic phase. PMID:27583653

  8. Improved fair sampling of ground states in Ising spin glasses

    NASA Astrophysics Data System (ADS)

    Katzgraber, Helmut G.; Zhu, Zheng; Ochoa, Andrew J.

    2015-03-01

    Verifying that an optimization approach can sample all solutions that minimize a Hamiltonian is a stringent test for any newly-developed algorithm. While most solvers easily compute the minimum of a cost function for small to moderate input sizes, equiprobable sampling of all ground-state configurations (within Poissonian fluctuations) is much harder to obtain. Most notably, methods such as transverse-field quantum annealing fail in passing this test for certain highly-degenerate problems. Here we present an attempt to sample ground states for Ising spin glasses based on a combination of low-temperature parallel tempering Monte Carlo combined with the cluster algorithm by Houdayer. Because the latter is rejection free and obeys details balance, the ground-state manifold is efficiently sampled. We illustrate the approach for Ising spin glasses on the D-Wave Two quantum annealer topology, known as the Chimera graph, as well as two-dimensional Ising spin glasses.

  9. Probing quantum frustrated systems via factorization of the ground state.

    PubMed

    Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio

    2010-05-21

    The existence of definite orders in frustrated quantum systems is related rigorously to the occurrence of fully factorized ground states below a threshold value of the frustration. Ground-state separability thus provides a natural measure of frustration: strongly frustrated systems are those that cannot accommodate for classical-like solutions. The exact form of the factorized ground states and the critical frustration are determined for various classes of nonexactly solvable spin models with different spatial ranges of the interactions. For weak frustration, the existence of disentangling transitions determines the range of applicability of mean-field descriptions in biological and physical problems such as stochastic gene expression and the stability of long-period modulated structures.

  10. Estimation of beryllium ground state energy by Monte Carlo simulation

    SciTech Connect

    Kabir, K. M. Ariful; Halder, Amal

    2015-05-15

    Quantum Monte Carlo method represent a powerful and broadly applicable computational tool for finding very accurate solution of the stationary Schrödinger equation for atoms, molecules, solids and a variety of model systems. Using variational Monte Carlo method we have calculated the ground state energy of the Beryllium atom. Our calculation are based on using a modified four parameters trial wave function which leads to good result comparing with the few parameters trial wave functions presented before. Based on random Numbers we can generate a large sample of electron locations to estimate the ground state energy of Beryllium. Our calculation gives good estimation for the ground state energy of the Beryllium atom comparing with the corresponding exact data.

  11. Ground and Excited State Spectra of a Quantum Dot

    NASA Astrophysics Data System (ADS)

    Stewart, D. R.; Sprinzak, D.; Patel, S. R.; Marcus, C. M.; Duruoz, C. I.; Harris, J. S.

    1998-03-01

    We present linear and nonlinear magnetoconductance measurements of the ground and excited state spectra for successive electron occupancy in a gate defined lateral quantum dot. Previous measurementsfootnote D.R. Stewart, D. Sprinzak, C.M. Marcus, C.I. Duruoz and J.S. Harris Jr., Science 278, (1997). showed a direct correlation between the mth excited state of the N-electron system and the ground state of the (N+m)-electron system for m up to 4, consistent to a large degree with a single-particle picture. Here we report quantitative deviations of the excited state spectra from the spectrum of ground state magnetoconductances, attributed to many-body interactions in the finite system of N ~200 electrons. We also describe the behaviour of anticrossings in the ground state magnetoconductances. We acknowledge the support of JSEP (DAAH04-94-G-0058), ARO (DAAH04-95-1-0331), ONR-YIP (N00014-94-1-0622) and the NSF-PECASE program. D.S. acknowledges the support of MINERVA grant.

  12. Static Properties and Stark Effect of the Ground State of the HD Molecular Ion

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Drachman, Richard J.

    1999-01-01

    We have calculated static properties of the ground state of the HD(+) ion and its lowest-lying P-state without making use of the Born-Oppenheimer approximation, as was done in the case of H2(+) and D2(+) [Phys. Rev. A 58, 2787 (1998)]. The ion is treated as a three-body system whose ground state is spherically symmetric. The wavefunction is of generalized Hylleraas type, but it is necessary to include high powers of the internuclear distance to localize the nuclear motion. We obtain good values of the energies of the ground S-state and lowest P-state and compare them with earlier calculations. Expectation values are obtained for various operators, the Fermi contact parameters, and the permanent quadrupole moment. The cusp conditions are also calculated. The polarizability was then calculated using second-order perturbation theory with intermediate P pseudostates. Since the nuclei in HD(+) are not of equal mass there is dipole coupling between the lowest two rotational states, which are almost degenerate. This situation is carefully analyzed, and the Stark shift is calculated variationally as a function of the applied electric field.

  13. From local to global ground states in Ising spin glasses

    NASA Astrophysics Data System (ADS)

    Zintchenko, Ilia; Hastings, Matthew B.; Troyer, Matthias

    2015-01-01

    We consider whether it is possible to find ground states of frustrated spin systems by solving them locally. Using spin glass physics and Imry-Ma arguments in addition to numerical benchmarks we quantify the power of such local solution methods and show that for the average low-dimensional spin glass problem outside the spin glass phase the exact ground state can be found in polynomial time. In the second part we present a heuristic, general-purpose hierarchical approach which for spin glasses on chimera graphs and lattices in two and three dimensions outperforms, to our knowledge, any other solver currently around, with significantly better scaling performance than simulated annealing.

  14. Ground state microstructure of a ferrofluid thin layer

    SciTech Connect

    Prokopieva, T. A.; Danilov, V. A.; Kantorovich, S. S.

    2011-09-15

    Using a fine weave of theoretical analysis and computer simulations, we found various aggregates of magnetic single-domain nanoparticles, which can form in a quasi-two-dimensional (q2D) ferrofluid layer at low temperatures. Our theoretical investigation allowed us to obtain exact expressions and their asymptotes for the energies of each configuration. Thus, for ferrofluid q2D layers it proved possible to identify the ground states as a function of the particle number, size, and other system parameters. Our suggested approach can be used for the investigation of ground state structures in systems with more complex interparticle interactions.

  15. Ground states of the SU(N) Heisenberg model.

    PubMed

    Kawashima, Naoki; Tanabe, Yuta

    2007-02-02

    The SU(N) Heisenberg model with various single-row representations is investigated by quantum Monte Carlo simulations. While the zero-temperature phase boundary agrees qualitatively with the theoretical predictions based on the 1/N expansion, some unexpected features are also observed. For N> or =5 with the fundamental representation, for example, it is suggested that the ground states possess exact or approximate U(1) degeneracy. In addition, for the representation of Young tableau with more than one column, the ground state shows no valence-bond-solid order even at N greater than the threshold value.

  16. Characterizing Ground and Thermal States of Few-Body Hamiltonians

    NASA Astrophysics Data System (ADS)

    Huber, Felix; Gühne, Otfried

    2016-07-01

    The question whether a given quantum state is a ground or thermal state of a few-body Hamiltonian can be used to characterize the complexity of the state and is important for possible experimental implementations. We provide methods to characterize the states generated by two- and, more generally, k -body Hamiltonians as well as the convex hull of these sets. This leads to new insights into the question of which states are uniquely determined by their marginals and to a generalization of the concept of entanglement. Finally, certification methods for quantum simulation can be derived.

  17. Dissociation energy of the ground state of NaH

    NASA Astrophysics Data System (ADS)

    Huang, Hsien-Yu; Lu, Tsai-Lien; Whang, Thou-Jen; Chang, Yung-Yung; Tsai, Chin-Chun

    2010-07-01

    The dissociation energy of the ground state of NaH was determined by analyzing the observed near dissociation rovibrational levels. These levels were reached by stimulated emission pumping and fluorescence depletion spectroscopy. A total of 114 rovibrational levels in the ranges 9≤v″≤21 and 1≤J″≤14 were assigned to the X Σ1+ state of NaH. The highest vibrational level observed was only about 40 cm-1 from the dissociation limit in the ground state. One quasibound state, above the dissociation limit and confined by the centrifugal barrier, was observed. Determining the vibrational quantum number at dissociation vD from the highest four vibrational levels yielded the dissociation energy De=15 815±5 cm-1. Based on new observations and available data, a set of Dunham coefficients and the rotationless Rydberg-Klein-Rees curve were constructed. The effective potential curve and the quasibound states were discussed.

  18. Microwave Spectroscopy of Trans-Ethyl Methyl Ether in the Ground State

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kaori; Sakai, Yusuke; Tsunekawa, Shozo; Miyamoto, Taihei; Fujitake, Masaharu; Ohashi, Nobukimi

    2013-06-01

    The trans-ethyl methyl ether molecule (CH_3CH_2OCH_3) has two inequivalent methyl group internal rotors which corresponds to the two vibrational motions, ν_{28} and ν_{29}. Due to these internal rotations, a rotational transition could be split into maximum five components. The skeletal torsion (ν_{30}) is another low-lying state (ν_{30}) that interacts with the ν_{28} and ν_{29} modes. The microwave spectra of the trans-ethyl methyl ether molecule in the ν_{28} = 1, ν_{29} = 1, and ν_{30} = 1, 2 and 3 have been extensively studied by using Hougen's tunneling matrix formalism. The microwave spectroscopy in the ground state was studied by several groups. The splitting due to the ν_{28} mode (C-CH_3 internal rotation) is small in the ground state and was not fully resolved in most of the previous studied rotational transitions. In this paper, we report the results of the pulsed nozzle-jet Fourier transform microwave spectroscopy so as to measure the fully resolved spectra. The submillmeter wave spectroscopy was also carried out. Our analysis including the previously reported transitions would be useful for astronomical observations. K. Kobayashi, T. Matsui, N. Mori, S. Tsunekawa, and N. Ohashi J. Mol. Spectrosc. {269}, 242 2011. K. Kobayashi, T. Matsui, S. Tsunekawa, and N. Ohashi J. Mol. Spectrosc. {255}, 164 2009. K. Kobayashi, T. Matsui, N. Mori, S. Tsunekawa, and N. Ohashi J. Mol. Spectrosc.{251}, 301 2008. K. Kobayashi, K. Murata, S. Tsunekawa, and N. Ohashi Int. Symposium on Mol. Spectrosc., 65th Meeting TH15 2010.} M. Hayashi, and K. Kuwada J. Mol. Structure {28}, 147 1975. M. Hayashi, and M. Adachi J. Mol. Structure {78}, 53 1982. S. Tsunekawa, Y. Kinai, Y. Kondo, H. Odashima, and K. Takagi Molecules {8}, 103 2003. U. Fuchs, G. Winnewisser, P. Groner, F. C. De Lucia, and E. Herbst Astrophys. J. Suppl. {144}, 277 2003.

  19. Single-configuration descriptions of atomic ground and excited states - Ground states of He, Li, and Be

    NASA Astrophysics Data System (ADS)

    Fletcher, Graham D.; Doggett, Graham; Howard, Alan S.

    1992-11-01

    A first-derivative variational principle is applied to the optimization of a single-configuration spin-coupled wave function to determine the ground states of some atoms. An orbital is chosen and optimized, and an expansion is taken for the orbital over a set of primitive atomic orbitals. Expected values of spin-free and -dependent operators are developed, and optimum wave-function parameters are determined for evaluating radial moments and radial density functions from spin or spinless one-electron density functions. The method is applied to the ground-state properties of He, Li, and Be by means of even-tempered and Clementi-Roetti basis sets. Energy profiles are determined for spin-coupled and full configuration-interaction computations. The ground states of He, Li, and Be are found to have energy profiles with a global minimum and at least on local minimum.

  20. Striped spin liquid crystal ground state instability of kagome antiferromagnets.

    PubMed

    Clark, Bryan K; Kinder, Jesse M; Neuscamman, Eric; Chan, Garnet Kin-Lic; Lawler, Michael J

    2013-11-01

    The Dirac spin liquid ground state of the spin 1/2 Heisenberg kagome antiferromagnet has potential instabilities. This has been suggested as the reason why it does not emerge as the ground state in large-scale numerical calculations. However, previous attempts to observe these instabilities have failed. We report on the discovery of a projected BCS state with lower energy than the projected Dirac spin liquid state which provides new insight into the stability of the ground state of the kagome antiferromagnet. The new state has three remarkable features. First, it breaks spatial symmetry in an unusual way that may leave spinons deconfined along one direction. Second, it breaks the U(1) gauge symmetry down to Z(2). Third, it has the spatial symmetry of a previously proposed "monopole" suggesting that it is an instability of the Dirac spin liquid. The state described herein also shares a remarkable similarity to the distortion of the kagome lattice observed at low Zn concentrations in Zn-paratacamite and in recently grown single crystals of volborthite suggesting it may already be realized in these materials.

  1. Electron scattering off the ground-state band and the. gamma. band in sup 150 Nd

    SciTech Connect

    Sandor, R.K.J.; Blok, H.P.; Garg, U.; Girod, M.; Harakeh, M.N.; de Jager, C.W.; de Vries, H. Service de Physique et Techniques Nucleaires, Commissariat a l'Energie Atomique, Bruyeres-le-Chatel, Boite Postale 12, F-91680 Bruyeres-le-Chatel, France Nationaal Instituut voor Kernfysica en Hoge-Energiefysica, sectie K , P.O. Box 4395, 1009AJ Amsterdam, The Netherlands Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556)

    1991-05-01

    Inelastic electron scattering to levels of the ground-state band and the {gamma} band in {sup 150}Nd was studied in a momentum transfer range of 0.5 to 2.8 fm{sup {minus}1}. The extracted transition charge densities were compared to microscopic Hartree-Fock-Boguliubov calculations. The overall agreement between the data and the calculations is good, indicating that the dynamic properties of the rotational collective degrees of freedom in statically deformed nuclei can be well described in this microscopic model.

  2. Search for ground state proton emission from sup 65 As and sup 69 Br

    SciTech Connect

    Robertson, J.D.; Reiff, J.E.; Lang, T.F.; Moltz, D.M.; Cerny, J. Nuclear Science Division, Lawrence Berkeley Laboratory, University of California, Berkeley, CA )

    1990-11-01

    The ground state proton decays of {sup 65}As and {sup 69}Br have been searched for in {sup 28}Si and {sup 32}S bombardments of a natural calcium target. These studies employed a newly developed rapidly rotating recoil-catcher wheel and a low-energy particle-identification telescope. No proton groups that could be assigned to either of these nuclides were observed. The minimum detectable limits indicate that {sup 65}As and {sup 69}Br either decay predominantly by beta emission or have half-lives less than 100 {mu}s. The overall evidence strongly indicates that {sup 65}As predominantly beta decays.

  3. The wave function for the ground state of H

    NASA Astrophysics Data System (ADS)

    Fontenelle, Marcia T.; Gallas, Jason A. C.; Gallas, Marcia R.

    1986-10-01

    The ground-state energy of H(-) is investigated using a variational function proposed by Wu and Tsai (1985). Contrary to the conclusions of Wu and Tsai, it is found that the Wu and Tsai function produces results comparable with a previous calculation of Williamson (1942). Furthermore, the explicit formulas given in the present paper can easily be applied to the helium isoelectronic series.

  4. Nuclear ground-state masses and deformations: FRDM(2012)

    SciTech Connect

    Moller, P.; Sierk, A. J.; Ichikawa, T.; Sagawa, H.

    2016-03-25

    Here, we tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from 16O to A=339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient LL, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to ground-state masses.

  5. Nuclear ground-state masses and deformations: FRDM(2012)

    DOE PAGES

    Moller, P.; Sierk, A. J.; Ichikawa, T.; ...

    2016-03-25

    Here, we tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from 16O to A=339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensivemore » and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient LL, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to ground-state masses.« less

  6. Ground states of the massless Derezinski-Gerard model

    SciTech Connect

    Ohkubo, Atsushi

    2009-11-15

    We consider the massless Derezinski-Gerard model introduced by Derezinski and Gerard in 1999. We give a sufficient condition for the existence of a ground state of the massless Derezinski-Gerard model without the assumption that the Hamiltonian of particles has compact resolvent.

  7. Tuning ground states and excitations in complex electronic materials

    SciTech Connect

    Bishop, A.R.

    1996-09-01

    Modern electronic materials are characterized by a great variety of broken-symmetry ground states and excitations. Their control requires understanding and tuning underlying driving forces of spin-charge-lattice coupling, critical to macroscopic properties and applications. We report representative model calculations which demonstrate some of the richness of the phenomena and the challenges for successful microscopic modeling.

  8. Selected bibliography of ground-water in the United States

    SciTech Connect

    Ward-McLemore, E.

    1984-01-01

    This bibliography contains 899 records related to the hydrology of the US. Specific topics include, but are not limited to: aquifers; artesian wells; geophysics; ground water; flow models; pollution; tritium; water levels; water policy; and legal aspects. The subject index provides listings of records related to each state. Some of the items (81) are themselves bibliographies.

  9. Quantum mechanical ground state of hydrogen obtained from classical electrodynamics

    NASA Astrophysics Data System (ADS)

    Cole, Daniel C.; Zou, Yi

    2003-10-01

    The behavior of a classical charged point particle under the influence of only a Coulombic binding potential and classical electromagnetic zero-point radiation, is shown to agree closely with the probability density distribution of Schrödinger's wave equation for the ground state of hydrogen. These results again raise the possibility that the main tenets of stochastic electrodynamics (SED) are correct.

  10. Nuclear ground-state masses and deformations: FRDM(2012)

    NASA Astrophysics Data System (ADS)

    Möller, P.; Sierk, A. J.; Ichikawa, T.; Sagawa, H.

    2016-05-01

    We tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from 16O to A = 339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient L, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to ground-state masses.

  11. Speed of Markovian relaxation toward the ground state

    SciTech Connect

    Vogl, Malte; Schaller, Gernot; Brandes, Tobias

    2010-01-15

    For sufficiently low reservoir temperatures, it is known that open quantum systems subject to decoherent interactions with the reservoir relax toward their ground state in the weak coupling limit. Within the framework of quantum master equations, this is formalized by the Born-Markov-secular (BMS) approximation, where one obtains the system Gibbs state with the reservoir temperature as a stationary state. When the solution to some problem is encoded in the (isolated) ground state of a system Hamiltonian, decoherence can therefore be exploited for computation. The computational complexity is then given by the scaling of the relaxation time with the system size n. We study the relaxation behavior for local and nonlocal Hamiltonians that are coupled dissipatively with local and nonlocal operators to a bosonic bath in thermal equilibrium. We find that relaxation is generally more efficient when coherences of the density matrix in the system energy eigenbasis are taken into account. In addition, the relaxation speed strongly depends on the matrix elements of the coupling operators between initial state and ground state. We show that Dicke superradiance is a special case of our relaxation models and can thus be understood as a coherence-assisted relaxation speedup.

  12. Coherent control of molecular rotational state populations by periodic phase-step modulation

    SciTech Connect

    Zhang Shian; Wu Meizhen; Lu Chenhui; Jia Tianqing; Sun Zhenrong

    2011-10-15

    We theoretically demonstrate that the molecular rotational state populations through an impulsive nonresonant Raman process can be manipulated by shaping the femtosecond laser pulse with a periodic phase-step modulation. We show that, by precisely controlling these parameters characterizing the periodic phase-step modulation, both the odd and even rotational state populations can be completely suppressed or reconstructed as that induced by the transform-limited laser pulse, and the relative excitation between the odd and even rotational state populations can also be obtained. Furthermore, we show that the field-free molecular alignment can be manipulated due to the modulation of the odd and even rotational state populations.

  13. Rotating goblet and talking profiles: does a rotating goblet increase the figural dominance of profiles in Rubin's type of figure-ground reversal patterns?

    PubMed

    Wake, Hiromi; Wake, Tenji; Oyama, Tadasu

    2014-01-01

    We present a novel three-dimensional (3-D) version of Rubin's classical bistable goblet-profiles figure. An actual goblet sculpture was produced and rotated on a turntable in front of a white background. As the goblet rotates about its central axis, small circular asymmetries around the lips and chin region give a clear impression of two white profiles talking to each other. Although the profiles actually correspond to empty space or white background, they are more likely to be perceived as 'figure' than the 3-D goblet itself. Four experiments that presented the actual goblet (experiment 1) or two-dimensional (2-D) movies of it (experiments 2-4) were designed to verify these observations. We measured perceptual dominance of profiles as 'figure' and rate of reversal as a function of three factors: motion (static vs rotating), orientation (upright vs inverted), and configuration (face-to-face vs back-to-back). Results for the rotating goblet showed a statistically reliable preference for perceiving the talking profiles as 'figure'. Deforming the profiles by manipulating the vertex angle of the mouth region produced an inverted U-shaped curve with the peak representing the stimulus condition in which the profiles perception was most remarkable. We discussed a number of 3-D and 2-D figure-ground factors that might apply to this rather complex stimulus situation.

  14. On the weighting of SABER temperature profiles for comparison with ground based hydroxyl rotational temperatures.

    NASA Astrophysics Data System (ADS)

    French, William; Mulligan, Frank

    2010-05-01

    Kinetic temperature profiles are retrieved from limb-emission radiance measurements of CO2 at 15 and 4.3 um by the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument on the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) satellite. Profiles extend from about 20-120km and measurements are available since the spacecraft launch in Dec-2001. Hydroxyl (6-2) band rotational temperatures are measured using a ground-based scanning spectrometer at Davis station, Antarctica (68°S, 78°E). Measurements are available each year since 1995 on nights between early February and late October, when the sun is more than 6° below the horizon. In order to compare temperatures from these two instruments we must derive hydroxyl layer equivalent temperatures for the SABER profiles using a weighting function which represents the hydroxyl layer profile. In this study, we examine a number of different weighting profiles to determine the best equivalent to hydroxyl nightly average temperatures at Davis. These profiles include (1) the customary Gaussian peaked at 87km and width 8km [Baker and Stair, 1988 :Physica Scripta. 37 611-622], (2) the layer profile derived from WINDIIUARS hydroxyl height profiles [She and Lowe, 1998 :JASTP 60, 1573-1583], (3) layer profiles derived from the hydroxyl volume emission rate (VER) from the SABER OH-B channel at 1.6um, which contains the Meinel OH(4-2) and OH(5-3) bands and (4) a Gaussian fitted to the SABER hydroxyl VER peak. The comparison is made with approximately 2500 SABER retrievals from overpasses within 500km of Davis station, and with solar zenith angle >97°, which have coincident hydroxyl temperature measurements over the 8 winters between 2002 and 2009. Due to the satellite 60 day yaw cycle the sampling over Davis has occurred in approximately the same three time intervals each year; between days 75-140, 196-262 and 323-014, however the latter interval is entirely rejected on the solar zenith

  15. Quantum quenches in the thermodynamic limit. II. Initial ground states.

    PubMed

    Rigol, Marcos

    2014-09-01

    A numerical linked-cluster algorithm was recently introduced to study quantum quenches in the thermodynamic limit starting from thermal initial states [M. Rigol, Phys. Rev. Lett. 112, 170601 (2014)]. Here, we tailor that algorithm to quenches starting from ground states. In particular, we study quenches from the ground state of the antiferromagnetic Ising model to the XXZ chain. Our results for spin correlations are shown to be in excellent agreement with recent analytical calculations based on the quench action method. We also show that they are different from the correlations in thermal equilibrium, which confirms the expectation that thermalization does not occur in general in integrable models even if they cannot be mapped to noninteracting ones.

  16. Guidelines for ground motion definition for the eastern United States

    SciTech Connect

    Gwaltney, R.C.; Aramayo, G.A.; Williams, R.T.

    1985-06-01

    Guidelines for the determination of earthquake ground motion definition for the eastern United States are established here. Both far-field and near-field guidelines are given. The guidelines were based on an extensive review of the current procedures for specifying ground motion in the United States. Both empirical and theoretical procedures were used in establishing the guidelines because of the low seismicity in the eastern United States. Only a few large- to great-sized earthquakes (M/sub s/ > 7.5) have occurred in this region, no evidence of tectonic surface ruptures related to historic or Holocene earthquakes has been found, and no currently active plate boundaries of any kind are known in this region. Very little instrumented data have been gathered in the East. Theoretical procedures are proposed so that in regions of almost no data, a reasonable level of seismic ground motion activity can be assumed. The guidelines are to be used to develop the safe shutdown earthquake (SSE). A new procedure for establishing the operating basis earthquake (OBE) is proposed, in particular for the eastern United States. The OBE would be developed using a probabilistic assessment of the geological conditions and the recurrence of seismic events at a site. These guidelines should be useful in development of seismic design requirements for future reactors. 17 refs., figs., tabs.

  17. Periodic Striped Ground States in Ising Models with Competing Interactions

    NASA Astrophysics Data System (ADS)

    Giuliani, Alessandro; Seiringer, Robert

    2016-11-01

    We consider Ising models in two and three dimensions, with short range ferromagnetic and long range, power-law decaying, antiferromagnetic interactions. We let J be the ratio between the strength of the ferromagnetic to antiferromagnetic interactions. The competition between these two kinds of interactions induces the system to form domains of minus spins in a background of plus spins, or vice versa. If the decay exponent p of the long range interaction is larger than d + 1, with d the space dimension, this happens for all values of J smaller than a critical value J c ( p), beyond which the ground state is homogeneous. In this paper, we give a characterization of the infinite volume ground states of the system, for p > 2 d and J in a left neighborhood of J c ( p). In particular, we prove that the quasi-one-dimensional states consisting of infinite stripes ( d = 2) or slabs ( d = 3), all of the same optimal width and orientation, and alternating magnetization, are infinite volume ground states. Our proof is based on localization bounds combined with reflection positivity.

  18. Coupled cluster calculation for ground state properties of closed-shell nuclei and single hole states.

    NASA Astrophysics Data System (ADS)

    Mihaila, Bogdan; Heisenberg, Jochen

    2000-04-01

    We continue the investigations of ground state properties of closed-shell nuclei using the Argonne v18 realistic NN potential, together with the Urbana IX three-nucleon interaction. The ground state wave function is used to calculate the charge form factor and charge density. Starting with the ground state wave function of the closed-shell nucleus, we use the equation of motion technique to calculate the ground state and excited states of a neighboring nucleus. We then generate the corresponding magnetic form factor. We correct for distortions due to the interaction between the electron probe and the nuclear Coulomb field using the DWBA picture. We compare our results with the available experimental data. Even though our presentation will focus mainly on the ^16O and ^15N nuclei, results for other nuclei in the p and s-d shell will also be presented.

  19. Significance of rotating ground motions on nonlinear behavior of symmetric and asymmetric buildings in near fault sites

    USGS Publications Warehouse

    Kalkan, Erol; ,

    2012-01-01

    Building codes in the U.S. require at least two horizontal ground motion components for three-dimensional (3D) response history analysis (RHA) of structures. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHA analyses should be performed separately (when FN and then FP are aligned with transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all non-redundant rotation angles. This assumption is examined here using 3D computer models of a single-story structure having symmetric (that is, torsionally-stiff) and asymmetric (that is, torsionally flexible) layouts subjected to an ensemble of bi-directional near-fault strong ground motions with and without apparent velocity pulses. In this parametric study, the elastic vibration period of the structures is varied from 0.2 to 5 seconds, and yield strength reduction factors R is varied from a value that leads to linear-elastic design to 3 and 5. The influence that the rotation angle of the ground motion has on several engineering demand parameters (EDPs) is examined in linear-elastic and nonlinear-inelastic domains to form a benchmark for evaluating the use of the FN/FP directions as well as the maximum-direction (MD) ground motion, a new definition of horizontal ground motions for use in the seismic design of structures according to the 2009 NEHRP Provisions and Commentary.

  20. Electric dipole moment function of the X1 Sigma/+/ state of CO - Vibration-rotation matrix elements for transitions of gas laser and astrophysical interest

    NASA Technical Reports Server (NTRS)

    Chackerian, C., Jr.

    1976-01-01

    The electric dipole moment function of the ground electronic state of carbon monoxide has been determined by combining numerical solutions of the radial Schrodinger equation with absolute intensity data of vibration-rotation bands. The derived dipole moment function is used to calculate matrix elements of interest to stellar astronomy and of importance in the carbon monoxide laser.

  1. The valence-fluctuating ground state of plutonium.

    PubMed

    Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; Abernathy, Douglas L; Lumsden, Mark D; Lawrence, John M; Thompson, Joe D; Lander, Gerard H; Mitchell, Jeremy N; Richmond, Scott; Ramos, Mike; Trouw, Frans; Zhu, Jian-Xin; Haule, Kristjan; Kotliar, Gabriel; Bauer, Eric D

    2015-07-01

    A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant ground states are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. Our study reveals that the ground state of plutonium is governed by valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium's magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials.

  2. The valence-fluctuating ground state of plutonium

    PubMed Central

    Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; Abernathy, Douglas L.; Lumsden, Mark D.; Lawrence, John M.; Thompson, Joe D.; Lander, Gerard H.; Mitchell, Jeremy N.; Richmond, Scott; Ramos, Mike; Trouw, Frans; Zhu, Jian-Xin; Haule, Kristjan; Kotliar, Gabriel; Bauer, Eric D.

    2015-01-01

    A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant ground states are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. Our study reveals that the ground state of plutonium is governed by valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium’s magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials. PMID:26601219

  3. Ground-state structures of atomic metallic hydrogen.

    PubMed

    McMahon, Jeffrey M; Ceperley, David M

    2011-04-22

    Ab initio random structure searching using density functional theory is used to determine the ground-state structures of atomic metallic hydrogen from 500 GPa to 5 TPa. Including proton zero-point motion within the harmonic approximation, we estimate that molecular hydrogen dissociates into a monatomic body-centered tetragonal structure near 500 GPa (r(s)=1.23) that remains stable to 1 TPa (r(s)=1.11). At higher pressures, hydrogen stabilizes in an …ABCABC… planar structure that is similar to the ground state of lithium, but with a different stacking sequence. With increasing pressure, this structure compresses to the face-centered cubic lattice near 3.5 TPa (r(s)=0.92).

  4. Monte Carlo Ground State Energy for Trapped Boson Systems

    NASA Astrophysics Data System (ADS)

    Rudd, Ethan; Mehta, N. P.

    2012-06-01

    Diffusion Monte Carlo (DMC) and Green's Function Monte Carlo (GFMC) algorithms were implemented to obtain numerical approximations for the ground state energies of systems of bosons in a harmonic trap potential. Gaussian pairwise particle interactions of the form V0e^-|ri-rj|^2/r0^2 were implemented in the DMC code. These results were verified for small values of V0 via a first-order perturbation theory approximation for which the N-particle matrix element evaluated to N2 V0(1 + 1/r0^2)^3/2. By obtaining the scattering length from the 2-body potential in the perturbative regime (V0φ 1), ground state energy results were compared to modern renormalized models by P.R. Johnson et. al, New J. Phys. 11, 093022 (2009).

  5. The valence-fluctuating ground state of plutonium

    SciTech Connect

    Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; Abernathy, Douglas L.; Lumsden, Mark D.; Lawrence, John M.; Thompson, Joe D.; Lander, Gerard H.; Mitchell, Jeremy N.; Richmond, Scott; Ramos, Mike; Trouw, Frans; Zhu, Jian -Xin; Haule, Kristjan; Kotliar, Gabriel; Bauer, Eric D.

    2015-07-10

    A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant ground states are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. In addition, our study reveals that the ground state of plutonium is governed by valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium’s magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials.

  6. Ground-State Phase Diagram of S = 1 Diamond Chains

    NASA Astrophysics Data System (ADS)

    Hida, Kazuo; Takano, Ken'ichi

    2017-03-01

    We investigate the ground-state phase diagram of a spin-1 diamond chain. Owing to a series of conservation laws, any eigenstate of this system can be expressed using the eigenstates of finite odd-length chains or infinite chains with spins 1 and 2. The ground state undergoes quantum phase transitions with varying λ, a parameter that controls frustration. Exact upper and lower bounds for the phase boundaries between these phases are obtained. The phase boundaries are determined numerically in the region not explored in a previous work [Takano et al., J. Phys.: Condens. Matter 8, 6405 (1996)].

  7. Room temperature skyrmion ground state stabilized through interlayer exchange coupling

    SciTech Connect

    Chen, Gong Schmid, Andreas K.; Mascaraque, Arantzazu; N'Diaye, Alpha T.

    2015-06-15

    Possible magnetic skyrmion device applications motivate the search for structures that extend the stability of skyrmion spin textures to ambient temperature. Here, we demonstrate an experimental approach to stabilize a room temperature skyrmion ground state in chiral magnetic films via exchange coupling across non-magnetic spacer layers. Using spin polarized low-energy electron microscopy to measure all three Cartesian components of the magnetization vector, we image the spin textures in Fe/Ni films. We show how tuning the thickness of a copper spacer layer between chiral Fe/Ni films and perpendicularly magnetized Ni layers permits stabilization of a chiral stripe phase, a skyrmion phase, and a single domain phase. This strategy to stabilize skyrmion ground states can be extended to other magnetic thin film systems and may be useful for designing skyrmion based spintronics devices.

  8. Simulation of the hydrogen ground state in stochastic electrodynamics

    NASA Astrophysics Data System (ADS)

    Nieuwenhuizen, Theo M.; Liska, Matthew T. P.

    2015-10-01

    Stochastic electrodynamics is a classical theory which assumes that the physical vacuum consists of classical stochastic fields with average energy \\frac{1}{2}{{\\hslash }}ω in each mode, i.e., the zero-point Planck spectrum. While this classical theory explains many quantum phenomena related to harmonic oscillator problems, hard results on nonlinear systems are still lacking. In this work the hydrogen ground state is studied by numerically solving the Abraham-Lorentz equation in the dipole approximation. First the stochastic Gaussian field is represented by a sum over Gaussian frequency components, next the dynamics is solved numerically using OpenCL. The approach improves on work by Cole and Zou 2003 by treating the full 3d problem and reaching longer simulation times. The results are compared with a conjecture for the ground state phase space density. Though short time results suggest a trend towards confirmation, in all attempted modellings the atom ionises at longer times.

  9. Observation of γ vibrations and alignments built on non-ground-state configurations in 156Dy

    NASA Astrophysics Data System (ADS)

    Majola, S. N. T.; Hartley, D. J.; Riedinger, L. L.; Sharpey-Schafer, J. F.; Allmond, J. M.; Beausang, C.; Carpenter, M. P.; Chiara, C. J.; Cooper, N.; Curien, D.; Gall, B. J. P.; Garrett, P. E.; Janssens, R. V. F.; Kondev, F. G.; Kulp, W. D.; Lauritsen, T.; McCutchan, E. A.; Miller, D.; Piot, J.; Redon, N.; Riley, M. A.; Simpson, J.; Stefanescu, I.; Werner, V.; Wang, X.; Wood, J. L.; Yu, C.-H.; Zhu, S.

    2015-03-01

    The exact nature of the lowest Kπ=2+ rotational bands in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the γ degree of freedom perpendicular to the nuclear symmetry axis. Very few such γ bands have been traced past the usual backbending rotational alignments of high-j nucleons. We have investigated the structure of positive-parity bands in the N =90 nucleus 156Dy , using the 148Nd(12C,4 n ) 156Dy reaction at 65 MeV, observing the resulting γ-ray transitions with the Gammasphere array. The even- and odd-spin members of the Kπ=2+ γ band are observed up to 32+ and 31+, respectively. This rotational band faithfully tracks the ground-state configuration to the highest spins. The members of a possible γ vibration built on the aligned yrast S band are observed up to spins 28+ and 27+. An even-spin positive-parity band, observed up to spin 24+, is a candidate for an aligned S band built on the seniority-zero configuration of the 02+ state at 676 keV. The crossing of this band with the 02+ band is at ℏ ωc=0.28 (1 ) MeV and is consistent with the configuration of the 02+ band not producing any blocking of the monopole pairing.

  10. Tuning the Ground State Symmetry of Acetylenyl Radicals

    PubMed Central

    2015-01-01

    The lowest excited state of the acetylenyl radical, HCC, is a 2Π state, only 0.46 eV above the ground state, 2Σ+. The promotion of an electron from a π bond pair to a singly occupied σ hybrid orbital is all that is involved, and so we set out to tune those orbital energies, and with them the relative energetics of 2Π and 2Σ+ states. A strategy of varying ligand electronegativity, employed in a previous study on substituted carbynes, RC, was useful, but proved more difficult to apply for substituted acetylenyl radicals, RCC. However, π-donor/acceptor substitution is effective in modifying the state energies. We are able to design molecules with 2Π ground states (NaOCC, H2NCC (2A″), HCSi, FCSi, etc.) and vary the 2Σ+–2Π energy gap over a 4 eV range. We find an inconsistency between bond order and bond dissociation energy measures of the bond strength in the Si-containing molecules; we provide an explanation through an analysis of the relevant potential energy curves. PMID:27162981

  11. Ground state nonuniversality in the random-field Ising model

    SciTech Connect

    Duxbury, P. M.; Meinke, J. H.

    2001-09-01

    Two attractive and often used ideas, namely, universality and the concept of a zero-temperature fixed point, are violated in the infinite-range random-field Ising model. In the ground state we show that the exponents can depend continuously on the disorder and so are nonuniversal. However, we also show that at finite temperature the thermal order-parameter exponent 1/2 is restored so that temperature is a relevant variable. Broader implications of these results are discussed.

  12. Alternative ground states enable pathway switching in biological electron transfer

    PubMed Central

    Abriata, Luciano A.; Álvarez-Paggi, Damián; Ledesma, Gabriela N.; Blackburn, Ninian J.; Vila, Alejandro J.; Murgida, Daniel H.

    2012-01-01

    Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative ground-state electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. These findings suggest a unique role for alternative or “invisible” electronic ground states in directional electron transfer. Moreover, it is shown that this energy gap and, therefore, the equilibrium between ground states can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton energy transduction. PMID:23054836

  13. Condensed ground states of frustrated Bose-Hubbard models

    SciTech Connect

    Moeller, G.; Cooper, N. R.

    2010-12-15

    We study theoretically the ground states of two-dimensional Bose-Hubbard models which are frustrated by gauge fields. Motivated by recent proposals for the implementation of optically induced gauge potentials, we focus on the situation in which the imposed gauge fields give rise to a pattern of staggered fluxes of magnitude {alpha} and alternating in sign along one of the principal axes. For {alpha}=1/2 this model is equivalent to the case of uniform flux per plaquette n{sub {phi}=}1/2, which, in the hard-core limit, realizes the 'fully frustrated' spin-1/2 XY model. We show that the mean-field ground states of this frustrated Bose-Hubbard model typically break translational symmetry. Given the presence of both a non-zero superfluid fraction and translational symmetry breaking, these phases are supersolid. We introduce a general numerical technique to detect broken symmetry condensates in exact diagonalization studies. Using this technique we show that, for all cases studied, the ground state of the Bose-Hubbard model with staggered flux {alpha} is condensed, and we obtain quantitative determinations of the condensate fraction. We discuss the experimental consequences of our results. In particular, we explain the meaning of gauge invariance in ultracold-atom systems subject to optically induced gauge potentials and show how the ability to imprint phase patterns prior to expansion can allow very useful additional information to be extracted from expansion images.

  14. Alternative ground states enable pathway switching in biological electron transfer

    SciTech Connect

    Abriata, Luciano A.; Alvarez-Paggi, Damian; Ledesma, Gabirela N.; Blackburn, Ninian J.; Vila, Alejandro J.; Murgida, Daniel H.

    2012-10-10

    Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative ground-state electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. In conclusion, these findings suggest a unique role for alternative or “invisible” electronic ground states in directional electron transfer. Moreover, it is shown that this energy gap and, therefore, the equilibrium between ground states can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton energy transduction.

  15. Alternative ground states enable pathway switching in biological electron transfer.

    PubMed

    Abriata, Luciano A; Álvarez-Paggi, Damián; Ledesma, Gabriela N; Blackburn, Ninian J; Vila, Alejandro J; Murgida, Daniel H

    2012-10-23

    Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant Cu(A) redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative ground-state electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. These findings suggest a unique role for alternative or "invisible" electronic ground states in directional electron transfer. Moreover, it is shown that this energy gap and, therefore, the equilibrium between ground states can be fine-tuned by minor perturbations, suggesting alternative ways through which protein-protein interactions and membrane potential may optimize and regulate electron-proton energy transduction.

  16. Ground state magnetic response of two coupled dodecahedra

    NASA Astrophysics Data System (ADS)

    Konstantinidis, N. P.

    2016-01-01

    The antiferromagnetic Heisenberg model on the dodecahedron possesses a number of ground state magnetization discontinuities in a field at the classical and quantum level, even though it lacks magnetic anisotropy. Here the model is considered for two dodecahedra coupled antiferromagnetically along one of their faces, as a first step to determine the magnetic response of collections of fullerene molecules. The magnetic response is determined from the competition among the intra-, interdodecahedral exchange and magnetic field energies. At the classical level the discontinuities of the isolated dodecahedron are renormalized by the interdodecahedral coupling, while new ones show up, with the maximum number of ground state discontinuities being six for a specific range of the coupling. In the full quantum limit where the individual spin magnitude s=\\frac{1}{2} , there are two ground state discontinuities originating in the single discontinuity of the isolated dodecahedron, and another one due to the intermolecular coupling, generating a total of three discontinuities which come one right after the other. These results show that the magnetic response of more than one dodecahedra interacting together is quite richer than the one of a single dodecahedron.

  17. Ground state magnetic response of two coupled dodecahedra.

    PubMed

    Konstantinidis, N P

    2016-01-13

    The antiferromagnetic Heisenberg model on the dodecahedron possesses a number of ground state magnetization discontinuities in a field at the classical and quantum level, even though it lacks magnetic anisotropy. Here the model is considered for two dodecahedra coupled antiferromagnetically along one of their faces, as a first step to determine the magnetic response of collections of fullerene molecules. The magnetic response is determined from the competition among the intra-, interdodecahedral exchange and magnetic field energies. At the classical level the discontinuities of the isolated dodecahedron are renormalized by the interdodecahedral coupling, while new ones show up, with the maximum number of ground state discontinuities being six for a specific range of the coupling. In the full quantum limit where the individual spin magnitude [Formula: see text], there are two ground state discontinuities originating in the single discontinuity of the isolated dodecahedron, and another one due to the intermolecular coupling, generating a total of three discontinuities which come one right after the other. These results show that the magnetic response of more than one dodecahedra interacting together is quite richer than the one of a single dodecahedron.

  18. Alternative ground states enable pathway switching in biological electron transfer

    DOE PAGES

    Abriata, Luciano A.; Alvarez-Paggi, Damian; Ledesma, Gabirela N.; ...

    2012-10-10

    Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative ground-state electronicmore » wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. In conclusion, these findings suggest a unique role for alternative or “invisible” electronic ground states in directional electron transfer. Moreover, it is shown that this energy gap and, therefore, the equilibrium between ground states can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton energy transduction.« less

  19. Efficient determination of alloy ground-state structures

    NASA Astrophysics Data System (ADS)

    Seko, Atsuto; Shitara, Kazuki; Tanaka, Isao

    2014-11-01

    We propose an efficient approach to accurately finding the ground-state structures in alloys based on the cluster expansion method. In this approach, a small number of candidate ground-state structures are obtained without any information regarding the energy. To generate the candidates, we employ the convex hull constructed from the correlation functions of all possible structures by using an efficient algorithm. This approach is applicable to not only simple lattices, but also complex lattices. First, we evaluate the convex hulls for binary alloys with four types of simple lattice. Then we discuss the structures on the vertices. To examine the accuracy of this approach, we perform a set of density functional theory calculations and the cluster expansion for the Ag-Au alloy and compare the formation energies of the vertex structures with those of all possible structures. As applications, the ground-state structures of the intermetallic compounds CuAu, CuAg, CuPd, AuAg, AuPd, AgPd, MoTa, MoW, and TaW are similarly evaluated. Finally, the energy distribution is obtained for different cation arrangements in the MgAl2O4 spinel, for which long-range interactions are essential for the accurate description of its energetics.

  20. High-resolution Fourier-transform infrared spectroscopy of the Coriolis coupled ground state and ν7 mode of ketenimine.

    PubMed

    Bane, Michael K; Robertson, Evan G; Thompson, Christopher D; Medcraft, Chris; Appadoo, Dominique R T; McNaughton, Don

    2011-06-21

    High resolution FTIR spectra of the short lived species ketenimine have been recorded in the regions 390-1300 cm(-1) and 20-110 cm(-1) using synchrotron radiation. Two thousand six hundred sixty transitions of the ν(7) band centered at 693 cm(-1) and 126 far-IR rotational transitions have been assigned. Rotational and centrifugal distortion parameters for the ν(7) mode were determined and local Fermi and b-axis Coriolis interactions with 2ν(12) are treated. A further refinement of the ground state, ν(12) and ν(8) parameters was also achieved, including the treatment of previously unrecognized ac-axis and ab-axis second order perturbations to the ground state.

  1. Two different ground states in K-intercalated polyacenes

    NASA Astrophysics Data System (ADS)

    Phan, Quynh T. N.; Heguri, Satoshi; Tamura, Hiroyuki; Nakano, Takehito; Nozue, Yasuo; Tanigaki, Katsumi

    2016-02-01

    The electronic states of potassium- (K-) intercalated zigzag-type polycyclic aromatic (PLA) hydrocarbon [polyacene PLAs] Kx(PLAs ) are studied for a series of the four smallest molecules: naphthalene (NN), anthracene (AN), tetracene (TN), and pentacene (PN), focusing on their 1:1 stoichiometric phases. Clear experimental differences are identified between the first group [K1(NN ) and K1(AN ) ] and the second group [K1(TN ) and K1(PN ) ] by magnetic, vibrational, and optical measurements. The first group is categorized as a Mott insulator with an antiferromagnetic ground state with energy of ˜10 meV, whereas the second group is classified as a band insulator via dimer formation due to the spin Peierls instability. In the latter system, the first thermally accessible triplet states are located far apart from the singlet ground states and are not detected by electron spin-resonance spectroscopy until 300 K being very different from what is observed for the hole-doped PN reported earlier. The results give a new systematic understanding on the electronic states of electron-doped PLAs sensitive to the energetic balance among on-site Coulomb repulsion, bandwidth, and the Peierls instability.

  2. Ground state energies from converging and diverging power series expansions

    NASA Astrophysics Data System (ADS)

    Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E.; Su, Q.; Grobe, R.

    2016-10-01

    It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh-Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state's spatial extension is comparable to L. Once the binding strength is so strong that the ground state's extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.

  3. Ground states of fermionic lattice Hamiltonians with permutation symmetry

    NASA Astrophysics Data System (ADS)

    Kraus, Christina V.; Lewenstein, Maciej; Cirac, J. Ignacio

    2013-08-01

    We study the ground states of lattice Hamiltonians that are invariant under permutations, in the limit where the number of lattice sites N→∞. For spin systems, these are product states, a fact that follows directly from the quantum de Finetti theorem. For fermionic systems, however, the problem is very different, since mode operators acting on different sites do not commute, but anticommute. We construct a family of fermionic states, F, from which such ground states can be easily computed. They are characterized by few parameters whose number only depends on M, the number of modes per lattice site. We also give an explicit construction for M=1,2. In the first case, F is contained in the set of Gaussian states, whereas in the second it is not. Inspired by that construction, we build a set of fermionic variational wave functions, and apply it to the Fermi-Hubbard model in two spatial dimensions, obtaining results that go beyond the generalized Hartree-Fock theory.

  4. Improved ground state and ν12 = 1 state rovibrational constants for ethylene-13C2 (13C2H4)

    NASA Astrophysics Data System (ADS)

    Gabona, M. G.; Tan, T. L.

    2014-05-01

    The Fourier transform infrared (FTIR) absorption spectrum of the ν12 fundamental band of ethylene-13C2 (13C2H4) was recorded in the frequency range of 1350-1550 cm-1 with unapodized resolution of 0.0063 cm-1. Improved upper state (ν12 = 1) rovibrational constants consisting of three rotational, five quartic and five sextic constants were derived by assigning and fitting 1731 infrared transitions using Watson's A-reduced Hamiltonian in the Ir representation. The root-mean-square deviation of the fit was 0.00030 cm-1. More higher-order upper state (ν12 = 1) constant were derived in the present analysis than previously reported. Improved ground state rovibrational constants were also determined from the fit of 1104 ground state combination differences (GSCD) with a root-mean-square deviation of 0.00029 cm-1. The A-type ν12 band centered at 1436.65409 ± 0.00002 cm-1 has a calculated inertial defect Δ12 is 0.242896 ± 0.000007 μÅ2. No indications of perturbation were found in the analysis of the band.

  5. Continuous Vibrational Cooling of Ground State Rb2

    NASA Astrophysics Data System (ADS)

    Tallant, Jonathan; Marcassa, Luis

    2014-05-01

    The process of photoassociation generally results in a distribution of vibrational levels in the electronic ground state that is energetically close to the dissociation limit. Several schemes have appeared that aim to transfer the population from the higher vibrational levels to lower ones, especially the ground vibrational state. We demonstrate continuous production of vibrationally cooled Rb2 using optical pumping. The vibrationally cooled molecules are produced in three steps. First, we use a dedicated photoassociation laser to produce molecules in high vibrational levels of the X1Σg+ state. Second, a broadband fiber laser at 1071 nm is used to transfer the molecules to lower vibrational levels via optical pumping through the A1Σu+ state. This process transfers the molecules from vibrational levels around ν ~= 113 to a distribution of levels where ν < 35. The molecules may then be further cooled using a broadband superluminescent diode near 685 nm that has its frequency spectrum shaped. The resulting vibrational distributions are probed using resonance-enhanced multiphoton ionization with a pulsed dye laser near 670 nm. The results are presented and compared with theoretical simulations. This work was supported by Fapesp and INCT-IQ.

  6. On the vibrational assignment in the ground electronic state of NO3

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Kentarou; Fujimori, Ryuji; Tang, Jian; Ishiwata, Takashi

    2015-08-01

    The vibration-rotational structure of the ground A2‧ state of the NO3 radical is re-considered, because Hirota (2015) presented an objection to the vibrational assignment of our previous papers (Kawaguchi et al., 2011, 2013; Fujimori et al., 2013). The present study examines the vibrational assignment in the following points, (1) laser induced fluorescence (LIF) spectra observed by Fukushima and Ishiwata in the 1050 cm-1 region, (2) Fourier transform (FT) spectra of vibrational bands from the v4 = 1 state, and a diode laser spectrum of the 2ν4 band. These considerations support our previous assignments, that is, ν3 + ν4 = 1492 cm-1 and ν3 = 1055 cm-1 for 14NO3.

  7. Mercury's rotational state from combined MESSENGER laser altimeter and image data

    NASA Astrophysics Data System (ADS)

    Stark, Alexander; Oberst, Jürgen; Preusker, Frank; Margot, Jean-Luc; Phillips, Roger J.; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.; Solomon, Sean C.

    2016-04-01

    With orbital data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, we measured the rotational state of Mercury. We developed a novel approach that combined digital terrain models from stereo images (stereo DTMs) and laser altimeter data, and we applied it to 3 years of MESSENGER observations. We find a large libration amplitude, which in combination with the measured obliquity confirms that Mercury possesses a liquid outer core. Our results confirm previous Earth-based observations of Mercury's rotational state. However, we measured a rotation rate that deviates significantly from the mean resonant rotation rate. The larger rotation rate can be interpreted as the signature of a long-period libration cycle. From these findings we derived new constraints on the interior structure of Mercury. The measured rotational parameters define Mercury's body-fixed frame and are critical for the coordinate system of the planet as well as for planning the future BepiColombo spacecraft mission.

  8. Determination of ground and excited state dipole moments via electronic Stark spectroscopy: 5-methoxyindole.

    PubMed

    Wilke, Josefin; Wilke, Martin; Meerts, W Leo; Schmitt, Michael

    2016-01-28

    The dipole moments of the ground and lowest electronically excited singlet state of 5-methoxyindole have been determined by means of optical Stark spectroscopy in a molecular beam. The resulting spectra arise from a superposition of different field configurations, one with the static electric field almost parallel to the polarization of the exciting laser radiation, the other nearly perpendicular. Each field configuration leads to different intensities in the rovibronic spectrum. With an automated evolutionary algorithm approach, the spectra can be fit and the ratio of both field configurations can be determined. A simultaneous fit of two spectra with both field configurations improved the precision of the dipole moment determination by a factor of two. We find a reduction of the absolute dipole moment from 1.59(3) D to 1.14(6) D upon electronic excitation to the lowest electronically excited singlet state. At the same time, the dipole moment orientation rotates by 54(∘) showing the importance of the determination of the dipole moment components. The dipole moment in the electronic ground state can approximately be obtained from a vector addition of the indole and the methoxy group dipole moments. However, in the electronically excited state, vector addition completely fails to describe the observed dipole moment. Several reasons for this behavior are discussed.

  9. Reanalysis of the ground and three torsional excited states of trans-ethyl methyl ether by using an IAM-like tunneling matrix formalism

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kaori; Sakai, Yusuke; Tsunekawa, Shozo; Miyamoto, Taihei; Fujitake, Masaharu; Ohashi, Nobukimi

    2016-03-01

    The trans-ethyl methyl ether has two inequivalent methyl internal rotors and shows tunneling splittings of maximum up to five components. However, the barrier of these two internal rotation potentials were relatively high and the five components were not resolved in the ground state microwave spectra. In this study, well-resolved Fourier transform microwave ground state spectrum was measured for the first time to resolve the five components. The ground state microwave spectra were reanalyzed based on these new measurements and the additional millimeter-wave spectra as well as those studied previously by Fuchs et al. Ninety Fourier transform microwave spectral lines were assigned to 107 transitions in the ground state and 3508 conventional microwave absorption lines were assigned up to Ka = 16 of the ground state, including all 707 lines reported by Fuchs et al. In addition, 10 transitions were observed by the double resonance experiment. They were least-squares-analyzed by the use of an internal axis method (IAM)-like tunneling matrix formalism based on an extended permutation-inversion group theoretical idea. Twenty-two molecular parameters composed of rotational constants, centrifugal distortion constants, internal rotation parameters and internal rotation tunneling parameters were determined for the ground state. The microwave spectra in the three torsionally excited states, that is, the ν28 = 1 C-CH3 torsional state, the ν29 = 1 O-CH3 torsional state and the ν30 = 1 skeletal torsional state, were also reanalyzed by using the IAM-like tunneling matrix formalism and somewhat extended line assignments.

  10. Basicity of coumarin derivatives in the ground and excited states

    SciTech Connect

    Ponomarev, O.A.; Mitina, V.G.; Vasina, E.R.; Yarmolenko, S.N.

    1985-07-01

    The acid-base properties of coumarin luminophores are widely used for widening the optical spectrum generated by lasers. The aim of this work was a quantitative study of the proton-acceptor capacity of a series of substituted coumarins at the H-complex formation stage and during protonation, and also to evaluate the basicity of these compounds in the first excited singlet state. The compounds chosen were the 4- and 7-substituted coumarins, most widely used in laser technology. In the ground state the sensitivity of the carbonyl group to the effect of a substituent was twice as great in position 4 as in position 7; for the excited state the effect was reversed.

  11. Calculation of electron scattering from the ground state of ytterbium

    SciTech Connect

    Bostock, Christopher J.; Fursa, Dmitry V.; Bray, Igor

    2011-05-15

    We report on the application of the convergent close-coupling method, in both relativistic and nonrelativistic formulations, to electron scattering from ytterbium. Angle-differential and integrated cross sections are presented for elastic scattering and excitation of the states (6s6p){sup 3}P{sub 0,1,2}, (6s6p){sup 1}P{sub 1}{sup o}, (6s7p){sup 1}P{sub 1}{sup o}, and (6s5d){sup 1}D{sub 2}{sup e} for a range of incident electron energies. We also present calculations of the total cross section, and angle-differential Stokes parameters for excitation of the (6s6p){sup 3}P{sub 1}{sup o} state from the ground state. A comparison is made with the relativistic distorted-wave method and experiments.

  12. Ground state of the universe in quantum cosmology

    NASA Astrophysics Data System (ADS)

    Gorobey, Natalia; Lukyanenko, Alexander

    2016-01-01

    We find a physical state of a closed universe with the minimal excitation of the universe expansion energy in quantum gravity. It is an analog of the vacuum state of the ordinary quantum field theory in the Minkowsky space, but in our approach an energy of space of a closed universe together with the energy of its matter content are minimized. This ground state is chosen among an enlarged set of physical states, compared with the ordinary covariant quantum gravity. In our approach, physical states are determined by weak constraints: quantum mechanical averages of gravitational constraint operators equal zero. As a result, they appear to be non-static in such a modification of quantum gravity. Quantum dynamics of the universe is described by Schrödinger equation with a cosmic time determined by weak gravitational constraints. In order to obtain the observed megascopic universe with the inflation stage just after its quantum beginning, a lot of the energy in the form of the inflaton scalar field condensate is prescribed to the initial state. Parameters of the initial state for a homogeneous model of the universe are calculated.

  13. Population shuffling between ground and high energy excited states

    PubMed Central

    Sabo, T Michael; Trent, John O; Lee, Donghan

    2015-01-01

    Stochastic processes powered by thermal energy lead to protein motions traversing time-scales from picoseconds to seconds. Fundamental to protein functionality is the utilization of these dynamics for tasks such as catalysis, folding, and allostery. A hierarchy of motion is hypothesized to connect and synergize fast and slow dynamics toward performing these essential activities. Population shuffling predicts a “top-down” temporal hierarchy, where slow time-scale conformational interconversion leads to a shuffling of the free energy landscape for fast time-scale events. Until now, population shuffling was only applied to interconverting ground states. Here, we extend the framework of population shuffling to be applicable for a system interconverting between low energy ground and high energy excited states, such as the SH3 domain mutants G48M and A39V/N53P/V55L from the Fyn tyrosine kinase, providing another tool for accessing the structural dynamics of high energy excited states. Our results indicate that the higher energy gauche− rotameric state for the leucine χ2 dihedral angle contributes significantly to the distribution of rotameric states in both the major and minor forms of the SH3 domain. These findings are corroborated with unrestrained molecular dynamics (MD) simulations on both the major and minor states of the SH3 domain demonstrating high correlations between experimental and back-calculated leucine χ2 rotameric populations. Taken together, we demonstrate how fast time-scale rotameric side-chain population distributions can be extracted from slow time-scale conformational exchange data further extending the scope and the applicability of the population shuffling model. PMID:26316263

  14. Population shuffling between ground and high energy excited states.

    PubMed

    Sabo, T Michael; Trent, John O; Lee, Donghan

    2015-11-01

    Stochastic processes powered by thermal energy lead to protein motions traversing time-scales from picoseconds to seconds. Fundamental to protein functionality is the utilization of these dynamics for tasks such as catalysis, folding, and allostery. A hierarchy of motion is hypothesized to connect and synergize fast and slow dynamics toward performing these essential activities. Population shuffling predicts a "top-down" temporal hierarchy, where slow time-scale conformational interconversion leads to a shuffling of the free energy landscape for fast time-scale events. Until now, population shuffling was only applied to interconverting ground states. Here, we extend the framework of population shuffling to be applicable for a system interconverting between low energy ground and high energy excited states, such as the SH3 domain mutants G48M and A39V/N53P/V55L from the Fyn tyrosine kinase, providing another tool for accessing the structural dynamics of high energy excited states. Our results indicate that the higher energy gauche - rotameric state for the leucine χ2 dihedral angle contributes significantly to the distribution of rotameric states in both the major and minor forms of the SH3 domain. These findings are corroborated with unrestrained molecular dynamics (MD) simulations on both the major and minor states of the SH3 domain demonstrating high correlations between experimental and back-calculated leucine χ2 rotameric populations. Taken together, we demonstrate how fast time-scale rotameric side-chain population distributions can be extracted from slow time-scale conformational exchange data further extending the scope and the applicability of the population shuffling model.

  15. Spatial competition of the ground states in 1111 iron pnictides

    NASA Astrophysics Data System (ADS)

    Lang, G.; Veyrat, L.; Gräfe, U.; Hammerath, F.; Paar, D.; Behr, G.; Wurmehl, S.; Grafe, H.-J.

    2016-07-01

    Using nuclear quadrupole resonance, the phase diagram of 1111 R FeAsO1 -xFx (R =La , Ce, Sm) iron pnictides is constructed as a function of the local charge distribution in the paramagnetic state, which features low-doping-like (LD-like) and high-doping-like (HD-like) regions. Compounds based on magnetic rare earths (Ce, Sm) display a unified behavior, and comparison with La-based compounds reveals the detrimental role of static iron 3 d magnetism on superconductivity, as well as a qualitatively different evolution of the latter at high doping. It is found that the LD-like regions fully account for the orthorhombicity of the system, and are thus the origin of any static iron magnetism. Orthorhombicity and static magnetism are not hindered by superconductivity but limited by dilution effects, in agreement with two-dimensional (2D) (respectively three-dimensional) nearest-neighbor square lattice site percolation when the rare earth is nonmagnetic (respectively magnetic). The LD-like regions are not intrinsically supportive of superconductivity, contrary to the HD-like regions, as evidenced by the well-defined Uemura relation between the superconducting transition temperature and the superfluid density when accounting for the proximity effect. This leads us to propose a complete description of the interplay of ground states in 1111 pnictides, where nanoscopic regions compete to establish the ground state through suppression of superconductivity by static magnetism, and extension of superconductivity by proximity effect.

  16. Universal crossover from ground-state to excited-state quantum criticality

    NASA Astrophysics Data System (ADS)

    Kang, Byungmin; Potter, Andrew C.; Vasseur, Romain

    2017-01-01

    We study the nonequilibrium properties of a nonergodic random quantum chain in which highly excited eigenstates exhibit critical properties usually associated with quantum critical ground states. The ground state and excited states of this system belong to different universality classes, characterized by infinite-randomness quantum critical behavior. Using strong-disorder renormalization group techniques, we show that the crossover between the zero and finite energy density regimes is universal. We analytically derive a flow equation describing the unitary dynamics of this isolated system at finite energy density from which we obtain universal scaling functions along the crossover.

  17. The ground state of the Frenkel-Kontorova model

    NASA Astrophysics Data System (ADS)

    Babushkin, A. Yu.; Abkaryan, A. K.; Dobronets, B. S.; Krasikov, V. S.; Filonov, A. N.

    2016-09-01

    The continual approximation of the ground state of the discrete Frenkel-Kontorova model is tested using a symmetric algorithm of numerical simulation. A "kaleidoscope effect" is found, which means that the curves representing the dependences of the relative extension of an N-atom chain vary periodically with increasing N. Stairs of structural transitions for N ≫ 1 are analyzed by the channel selection method with the approximation N = ∞. Images of commensurable and incommensurable structures are constructed. The commensurable-incommensurable phase transitions are stepwise.

  18. Triaxiality near the 110Ru ground state from Coulomb excitation

    NASA Astrophysics Data System (ADS)

    Doherty, D. T.; Allmond, J. M.; Janssens, R. V. F.; Korten, W.; Zhu, S.; Zielińska, M.; Radford, D. C.; Ayangeakaa, A. D.; Bucher, B.; Batchelder, J. C.; Beausang, C. W.; Campbell, C.; Carpenter, M. P.; Cline, D.; Crawford, H. L.; David, H. M.; Delaroche, J. P.; Dickerson, C.; Fallon, P.; Galindo-Uribarri, A.; Kondev, F. G.; Harker, J. L.; Hayes, A. B.; Hendricks, M.; Humby, P.; Girod, M.; Gross, C. J.; Klintefjord, M.; Kolos, K.; Lane, G. J.; Lauritsen, T.; Libert, J.; Macchiavelli, A. O.; Napiorkowski, P. J.; Padilla-Rodal, E.; Pardo, R. C.; Reviol, W.; Sarantites, D. G.; Savard, G.; Seweryniak, D.; Srebrny, J.; Varner, R.; Vondrasek, R.; Wiens, A.; Wilson, E.; Wood, J. L.; Wu, C. Y.

    2017-03-01

    A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2 = 12 s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the ground state provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.

  19. Ground state of a resonantly interacting Bose gas

    SciTech Connect

    Diederix, J. M.; Heijst, T. C. F. van; Stoof, H. T. C.

    2011-09-15

    We show that a two-channel mean-field theory for a Bose gas near a Feshbach resonance allows for an analytic computation of the chemical potential, and therefore the universal constant {beta}, at unitarity. To improve on this mean-field theory, which physically neglects condensate depletion, we study a variational Jastrow ansatz for the ground-state wave function and use the hypernetted-chain approximation to minimize the energy for all positive values of the scattering length. We also show that other important physical quantities such as Tan's contact and the condensate fraction can be directly obtained from this approach.

  20. Tetraphenylhexaazaanthracenes: 16π Weakly Antiaromatic Species with Singlet Ground States.

    PubMed

    Constantinides, Christos P; Zissimou, Georgia A; Berezin, Andrey A; Ioannou, Theodosia A; Manoli, Maria; Tsokkou, Demetra; Theodorou, Eleni; Hayes, Sophia C; Koutentis, Panayiotis A

    2015-08-21

    Tetraphenylhexaazaanthracene, TPHA-1, is a fluorescent zwitterionic biscyanine with a closed-shell singlet ground state. TPHA-1 overcomes its weak 16π antiaromaticity by partitioning its π system into 6π positive and 10π negative cyanines. The synthesis of TPHA-1 is low yielding and accompanied by two analogous TPHA isomers: the deep red, non-charge-separated, quinoidal TPHA-2, and the deep green TPHA-3 that partitions into two equal but oppositely charged 8π cyanines. The three TPHA isomers are compared.

  1. Photoabsorption by ground-state alkali-metal atoms.

    NASA Technical Reports Server (NTRS)

    Weisheit, J. C.

    1972-01-01

    Principal-series oscillator strengths and ground-state photoionization cross sections are computed for sodium, potassium, rubidium, and cesium. The degree of polarization of the photoelectrons is also predicted for each atom. The core-polarization correction to the dipole transition moment is included in all of the calculations, and the spin-orbit perturbation of valence-p-electron orbitals is included in the calculations of the Rb and Cs oscillator strengths and of all the photoionization cross sections. The results are compared with recent measurements.

  2. Magnetic ground states in nanocuboids of cubic magnetocrystalline anisotropy

    NASA Astrophysics Data System (ADS)

    Bonilla, F. J.; Lacroix, L.-M.; Blon, T.

    2017-04-01

    Flower and easy-axis vortex states are well-known magnetic configurations that can be stabilized in small particles. However, <111> vortex (V<111>), i.e. a vortex state with its core axis along the hard-axis direction, has been recently evidenced as a stable configuration in Fe nanocubes of intermediate sizes in the flower/vortex transition. In this context, we present here extensive micromagnetic simulations to determine the different magnetic ground states in ferromagnetic nanocuboids exhibiting cubic magnetocrystalline anisotropy (MCA). Focusing our study in the single-domain/multidomain size range (10-50 nm), we showed that V<111> is only stable in nanocuboids exhibiting peculiar features, such as a specific size, shape and magnetic environment, contrarily to the classical flower and easy-axis vortex states. Thus, to track experimentally these V<111> states, one should focused on (i) nanocuboids exhibiting a nearly perfect cubic shape (size distorsion <12%) made of (ii) a material which combines a zero or positive MCA and a high saturation magnetization, such as Fe or FeCo; and (iii) a low magnetic field environment, V<111> being only observed in virgin or remanent states.

  3. Ground state of bilayer hα-silica: mechanical and electronic properties

    NASA Astrophysics Data System (ADS)

    Han, Yang; Hu, Ming

    2015-12-01

    The family of two-dimensional (2D) crystals was recently joined by silica, one of the most abundant resources on earth. So far two different polymorphs of this material, namely a tetrahedra-shaped monolayer and a fully saturated bilayer structure, have been synthesized on various metal substrates and their fascinating properties enable 2D silica to hold promise in nanoelectronic device applications. In this paper a new ground state of bilayer—AAr-stacking hα-silica—has been discovered by first principles calculations. The new structure is featured with a formation of Si-Si bonds between all sp3 hybridized SiO3 triangular pyramids, lying respectively in different silica layers, with an intrinsic rotational angle of about 12.5° along the out-of-plane Si-Si bond. Due to the doubled number of Si-Si bonds in the new structure, the system energy is lowered by nearly three times more than that reported recently in literature (0.8 eV) (Özçelik et al 2014 Phys. Rev. Lett. 112 246803), when compared with the single layer hα-silica. A mechanical property investigation shows that the AAr-stacking bilayer hα-silica possesses high in-plane stiffness and a negative Poisson’s ratio, which stems from the intrinsic rotational angle of the SiO3 triangular pyramids. Strikingly, the negative Poisson’s ratio evolves into positive at a critical tensile strain ɛ ≈ 1.2%. Such negative-to-positive evolvement is associated with the adaptation of the rotational angle to the applied strain and the structure transition into the nearby valley of the energy landscape. The detailed transition process has been thoroughly analyzed. The electronic properties of the new ground state are also calculated, along with their response to the external strain. Our new ground state structure introduces a new member to the family of 2D bilayer silica materials and is expected to facilitate experimental studies identifying the related structures and exploring further physical and chemical

  4. Analytic continuation of the rotating black hole state counting

    NASA Astrophysics Data System (ADS)

    Achour, Jibril Ben; Noui, Karim; Perez, Alejandro

    2016-08-01

    In loop quantum gravity, a spherical black hole can be described in terms of a Chern-Simons theory on a punctured 2-sphere. The sphere represents the horizon. The punctures are the edges of spin-networks in the bulk which cross the horizon and carry quanta of area. One can generalize this construction and model a rotating black hole by adding an extra puncture colored with the angular momentum J in the 2-sphere. We compute the entropy of rotating black holes in this model and study its semi-classical limit. After performing an analytic continuation which sends the Barbero-Immirzi parameter to γ = ± i,weshowthattheleadingorderterminthesemi-classicalexpansionoftheentropy reproduces the Bekenstein-Hawking law independently of the value of J.

  5. Lifetimes of superdeformed rotational states in {sup 36}Ar.

    SciTech Connect

    Svensson, C. E.; Macchiavelli, A. O.; Juodagalvis, A.; Poves, A.; Ragnarsson, I.; Aberg, S.; Appelbe, D. E.; Austin, R. A. E.; Ball, G. C.; Carpenter, M. P.; Caurier, E.; Clark, R. M.; Cromaz, M.; Deleplanque, M. A.; Diamond, R. M.; Fallon, P.; Janssens, R. V. F.; Lane, G. J.; Lee, I. Y.; Nowacki, F.; Sarantites, D. G.; Stephens, F. S.; Vetter, K.; Ward, D.; Physics; LBNL; Lund Inst. of Tech.; Univ. Autonoma de Madrid; McMaster Univ.; TRIUMF; Univ. Louis Pasteur; Washington Univ.

    2001-06-01

    Lifetimes have been measured in a superdeformed rotational band recently identified in the N=Z nucleus {sup 36}Ar. A large low-spin quadrupole deformation ({beta}{sub 2}=0.46{+-}0.03) is confirmed and a decrease in the collectivity is observed as the high-spin band termination at I{sup {pi}}=16{sup +} is approached. Detailed comparisons of the experimental B(E2) values with the results of cranked Nilsson-Strutinsky and large-scale (s{sub 1/2}d{sub 3/2})-pf spherical shell model calculations indicate the need for a more refined treatment of transition matrix elements close to termination in the former, and the inclusion of the complete sd-pf model space in the latter description of this highly-collective rotational band.

  6. Equation of State Dependence of Gravitational Waves from Rapidly Rotating Core-Collapse

    NASA Astrophysics Data System (ADS)

    Richers, Sherwood; Ott, Christian D.; Abdikamalov, Ernazar

    2016-03-01

    We carry out axisymmetric simulations of rotating core-collapse, exploring over 92 precollapse rotational configurations and 18 different finite-temperature microphysical equations of state (EOS) using the general-relativistic hydrodynamical code CoCoNuT. Our focus is on gravitational wave (GW) emission. We find that the GW wave signature depends systematically on the rotation rate of the inner core at bounce and the compactness of the protoneutron star (PNS), set by the EOS and rotation. The GW signal from core bounce is almost independent of the EOS. However, the frequency of the post-bounce ring down signal from the fundamental quadrupole oscillation mode of the PNS is dependent on both rotation and the EOS, increasing with rotation rate and compactness. We will discuss the origin of the EOS-dependent f-mode frequency variation and its potential observability with Advanced LIGO.

  7. Charge transfer to ground-state ions produces free electrons

    NASA Astrophysics Data System (ADS)

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K.

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.

  8. Charge transfer to ground-state ions produces free electrons

    PubMed Central

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne–Kr mixed clusters. PMID:28134238

  9. Centrifugal stretching along the ground state band of Hf168

    NASA Astrophysics Data System (ADS)

    Costin, A.; Reese, M.; Ai, H.; Casten, R. F.; Dusling, K.; Fitzpatrick, C. R.; Gürdal, G.; Heinz, A.; McCutchan, E. A.; Meyer, D. A.; Möller, O.; Petkov, P.; Pietralla, N.; Qian, J.; Rainovski, G.; Werner, V.

    2009-02-01

    The lifetimes of the Jπ=4+, 6+, 8+, and 10+ levels along the ground state band in Hf168 were measured by means of the recoil distance Doppler shift (RDDS) method using the New Yale Plunger Device (NYPD) and the SPEEDY detection array at Wright Nuclear Structure Laboratory of Yale University. Excited states in Hf168 were populated using the Sn124(Ti48,4n) fusion evaporation reaction. The new lifetime values are sufficiently precise to clearly prove the increase of quadrupole deformation as a function of angular momentum in the deformed nucleus Hf168. The data agree with the predictions from the geometrical confined β-soft (CBS) rotor model that involves centrifugal stretching in a soft potential.

  10. Ground states of partially connected binary neural networks

    NASA Technical Reports Server (NTRS)

    Baram, Yoram

    1990-01-01

    Neural networks defined by outer products of vectors over (-1, 0, 1) are considered. Patterns over (-1, 0, 1) define by their outer products partially connected neural networks consisting of internally strongly connected, externally weakly connected subnetworks. Subpatterns over (-1, 1) define subnetworks, and their combinations that agree in the common bits define permissible words. It is shown that the permissible words are locally stable states of the network, provided that each of the subnetworks stores mutually orthogonal subwords, or, at most, two subwords. It is also shown that when each of the subnetworks stores two mutually orthogonal binary subwords at most, the permissible words, defined as the combinations of the subwords (one corresponding to each subnetwork), that agree in their common bits are the unique ground states of the associated energy function.

  11. Cloning and variation of ground state intestinal stem cells.

    PubMed

    Wang, Xia; Yamamoto, Yusuke; Wilson, Lane H; Zhang, Ting; Howitt, Brooke E; Farrow, Melissa A; Kern, Florian; Ning, Gang; Hong, Yue; Khor, Chiea Chuen; Chevalier, Benoit; Bertrand, Denis; Wu, Lingyan; Nagarajan, Niranjan; Sylvester, Francisco A; Hyams, Jeffrey S; Devers, Thomas; Bronson, Roderick; Lacy, D Borden; Ho, Khek Yu; Crum, Christopher P; McKeon, Frank; Xian, Wa

    2015-06-11

    Stem cells of the gastrointestinal tract, pancreas, liver and other columnar epithelia collectively resist cloning in their elemental states. Here we demonstrate the cloning and propagation of highly clonogenic, 'ground state' stem cells of the human intestine and colon. We show that derived stem-cell pedigrees sustain limited copy number and sequence variation despite extensive serial passaging and display exquisitely precise, cell-autonomous commitment to epithelial differentiation consistent with their origins along the intestinal tract. This developmentally patterned and epigenetically maintained commitment of stem cells is likely to enforce the functional specificity of the adult intestinal tract. Using clonally derived colonic epithelia, we show that toxins A or B of the enteric pathogen Clostridium difficile recapitulate the salient features of pseudomembranous colitis. The stability of the epigenetic commitment programs of these stem cells, coupled with their unlimited replicative expansion and maintained clonogenicity, suggests certain advantages for their use in disease modelling and regenerative medicine.

  12. Au42: A possible ground-state noble metallic nanotube

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Ning, Hua; Ma, Qing-Min; Liu, Ying; Li, You-Cheng

    2008-10-01

    A large hollow tubelike Au42 is predicted as a new ground-state configuration based on the scalar relativistic density functional theory. The shape of this new Au42 cluster is similar to a (5,5) single-wall gold nanotube, the two ends of which are capped by half of a fullerenelike Au32. In the same way, a series of Aun (n =37,42,47,52,57,62,67,72,…, Δn =5) tubelike structures has been constructed. The highest occupied molecular orbital-lowest unoccupied molecular orbital gaps suggested a significant semiconductor-conductor alternation in n ɛ[32,47]. Similar to the predictions and speculation of Daedalus [D. E. H. Jones, New Sci. 32, 245 (1966); E. Osawa, Superaromaticity (Kagaku, Kyoto, 1970), Vol. 25, pp. 854-863; Z. Yoshida and E. Osawa, Aromaticity Chemical Monograph (Kagaku Dojin, Kyoto, Japan, 1971), Vol. 22, pp. 174-176; D. A. Bochvar and E. G. Gal'pern, Dokl. Akad. Nauk SSSR 209, 610 (1973)], here a large hollow ground-state gold nanotube was predicted theoretically.

  13. Au42: a possible ground-state noble metallic nanotube.

    PubMed

    Wang, Jing; Ning, Hua; Ma, Qing-Min; Liu, Ying; Li, You-Cheng

    2008-10-07

    A large hollow tubelike Au(42) is predicted as a new ground-state configuration based on the scalar relativistic density functional theory. The shape of this new Au(42) cluster is similar to a (5,5) single-wall gold nanotube, the two ends of which are capped by half of a fullerenelike Au(32). In the same way, a series of Au(n) (n = 37, 42, 47, 52, 57, 62, 67, 72, ..., Delta n = 5) tubelike structures has been constructed. The highest occupied molecular orbital-lowest unoccupied molecular orbital gaps suggested a significant semiconductor-conductor alternation in n is an element of [32,47]. Similar to the predictions and speculation of Daedalus [D. E. H. Jones, New Sci. 32, 245 (1966); E. Osawa, Superaromaticity (Kagaku, Kyoto, 1970), Vol. 25, pp. 854-863; Z. Yoshida and E. Osawa, Aromaticity Chemical Monograph (Kagaku Dojin, Kyoto, Japan, 1971), Vol. 22, pp. 174-176; D. A. Bochvar and E. G. Gal'pern, Dokl. Akad. Nauk SSSR 209, 610 (1973)], here a large hollow ground-state gold nanotube was predicted theoretically.

  14. DNA-DNA interaction beyond the ground state

    NASA Astrophysics Data System (ADS)

    Lee, D. J.; Wynveen, A.; Kornyshev, A. A.

    2004-11-01

    The electrostatic interaction potential between DNA duplexes in solution is a basis for the statistical mechanics of columnar DNA assemblies. It may also play an important role in recombination of homologous genes. We develop a theory of this interaction that includes thermal torsional fluctuations of DNA using field-theoretical methods and Monte Carlo simulations. The theory extends and rationalizes the earlier suggested variational approach which was developed in the context of a ground state theory of interaction of nonhomologous duplexes. It shows that the heuristic variational theory is equivalent to the Hartree self-consistent field approximation. By comparison of the Hartree approximation with an exact solution based on the QM analogy of path integrals, as well as Monte Carlo simulations, we show that this easily analytically-tractable approximation works very well in most cases. Thermal fluctuations do not remove the ability of DNA molecules to attract each other at favorable azimuthal conformations, neither do they wash out the possibility of electrostatic “snap-shot” recognition of homologous sequences, considered earlier on the basis of ground state calculations. At short distances DNA molecules undergo a “torsional alignment transition,” which is first order for nonhomologous DNA and weaker order for homologous sequences.

  15. The valence-fluctuating ground state of plutonium

    DOE PAGES

    Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; ...

    2015-07-10

    A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant ground states are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. In addition, our study reveals that the ground state of plutonium is governed bymore » valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium’s magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials.« less

  16. Nuclear Magnetic Moment of the {sup 57}Cu Ground State

    SciTech Connect

    Minamisono, K.; Mertzimekis, T.J.; Pereira, J.; Mantica, P.F.; Pinter, J.S.; Stoker, J.B.; Tomlin, B.E.; Weerasiri, R.R.; Davies, A.D.; Hass, M.; Rogers, W.F.

    2006-03-17

    The nuclear magnetic moment of the ground state of {sup 57}Cu(I{sup {pi}}=3/2{sup -},T{sub 1/2}=196.3 ms) has been measured to be vertical bar {mu}({sup 57}Cu) vertical bar =(2.00{+-}0.05){mu}{sub N} using the {beta}-NMR technique. Together with the known magnetic moment of the mirror partner {sup 57}Ni, the spin expectation value was extracted as <{sigma}{sigma}{sub z}>=-0.78{+-}0.13. This is the heaviest isospin T=1/2 mirror pair above the {sup 40}Ca region for which both ground state magnetic moments have been determined. The discrepancy between the present results and shell-model calculations in the full fp shell giving {mu}({sup 57}Cu){approx}2.4{mu}{sub N} and <{sigma}{sigma}{sub z}>{approx}0.5 implies significant shell breaking at {sup 56}Ni with the neutron number N=28.

  17. DNA-DNA interaction beyond the ground state.

    PubMed

    Lee, D J; Wynveen, A; Kornyshev, A A

    2004-11-01

    The electrostatic interaction potential between DNA duplexes in solution is a basis for the statistical mechanics of columnar DNA assemblies. It may also play an important role in recombination of homologous genes. We develop a theory of this interaction that includes thermal torsional fluctuations of DNA using field-theoretical methods and Monte Carlo simulations. The theory extends and rationalizes the earlier suggested variational approach which was developed in the context of a ground state theory of interaction of nonhomologous duplexes. It shows that the heuristic variational theory is equivalent to the Hartree self-consistent field approximation. By comparison of the Hartree approximation with an exact solution based on the QM analogy of path integrals, as well as Monte Carlo simulations, we show that this easily analytically-tractable approximation works very well in most cases. Thermal fluctuations do not remove the ability of DNA molecules to attract each other at favorable azimuthal conformations, neither do they wash out the possibility of electrostatic "snap-shot" recognition of homologous sequences, considered earlier on the basis of ground state calculations. At short distances DNA molecules undergo a "torsional alignment transition," which is first order for nonhomologous DNA and weaker order for homologous sequences.

  18. Magnetic ground state of semiconducting transition-metal trichalcogenide monolayers

    DOE PAGES

    Sivadas, Nikhil; Daniels, Matthew W.; Swendsen, Robert H.; ...

    2015-06-16

    Layered transition-metal trichalcogenides with the chemical formula ABX3 have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic ground states of monolayers of Mn- and Cr-based semiconducting trichalcogenides.We show that the second and third nearest-neighbor exchange interactions (J2 and J3) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic ground state. Specifically, we find that monolayer CrSiTe3 is an antiferromagnet with a zigzag spin texture due to significant contribution from J3, whereas CrGeTe3 is a ferromagnet with a Curie temperaturemore » of 106 K. Monolayers of Mn compounds (MnPS3 and MnPSe3) always show antiferromagnetic N eel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. In conclusion, our study suggests that ABX3 can be a promising platform to explore two-dimensional magnetic phenomena.« less

  19. Magnetic ground state of semiconducting transition-metal trichalcogenide monolayers

    SciTech Connect

    Sivadas, Nikhil; Daniels, Matthew W.; Swendsen, Robert H.; Okamoto, Satoshi; Xiao, Di

    2015-06-16

    Layered transition-metal trichalcogenides with the chemical formula ABX3 have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic ground states of monolayers of Mn- and Cr-based semiconducting trichalcogenides.We show that the second and third nearest-neighbor exchange interactions (J2 and J3) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic ground state. Specifically, we find that monolayer CrSiTe3 is an antiferromagnet with a zigzag spin texture due to significant contribution from J3, whereas CrGeTe3 is a ferromagnet with a Curie temperature of 106 K. Monolayers of Mn compounds (MnPS3 and MnPSe3) always show antiferromagnetic N eel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. In conclusion, our study suggests that ABX3 can be a promising platform to explore two-dimensional magnetic phenomena.

  20. Effects of rotational states on the c/a ratio in solid hydrogens

    SciTech Connect

    Strzhemechny, Mikhail A.; Hemley, Russell J.

    2015-04-08

    We propose an approach to the problem of lattice distortions at low temperatures and ambient pressure in the solid hydrogens in their rotational ground states that explicitly accounts for the molecular nature of the constituent particles. The model is based on the idea that the second-order rotation-related correction to the ground-state energy depends on the lattice parameters. The calculated ground-state rotation-related contributions, δgs = c/a–(8/3)1/2, are negative for all species, amounting to about –1.5×10–5 for H2 and D2, whereas for HD this contribution is about –0.6×10–3, which is roughly 50 times larger. This substantial difference stems from the fact that the rotational dynamics in the homonuclear solids and in HD differ appreciably. Furthermore, the approach can be generalized to high pressures.

  1. Spectroscopic study on deuterated benzenes. I. Microwave spectra and molecular structure in the ground state

    SciTech Connect

    Kunishige, Sachi; Katori, Toshiharu; Baba, Masaaki; Nakajima, Masakazu; Endo, Yasuki

    2015-12-28

    We observed microwave absorption spectra of some deuterated benzenes and accurately determined the rotational constants of all H/D isotopomers in the ground vibrational state. Using synthetic analysis assuming that all bond angles are 120°, the mean bond lengths were obtained to be r{sub 0}(C–C) = 1.3971 Å and r{sub 0}(C–H) = r{sub 0}(C–D) = 1.0805 Å. It has been concluded that the effect of deuterium substitution on the molecular structure is negligibly small and that the mean bond lengths of C–H and C–D are identical unlike small aliphatic hydrocarbons, in which r{sub 0}(C–D) is about 5 mÅ shorter than r{sub 0}(C–H). It is considered that anharmonicity is very small in the C–H stretching vibration of aromatic hydrocarbons.

  2. Millimeter-wave spectrum of DCCCHO in the ground vibrational state

    NASA Astrophysics Data System (ADS)

    Takami, Michio

    1980-04-01

    About 140 a- and b-type millimeter-wave transitions of propynal- d1, DCCCHO, were measured in the ground vibrational state. The accurate rotational and centrifugal distortion constants were determined from the observed frequencies including the previous microwave measurements. Seven microwave transitions observed by infrared-microwave double resonance were also included in the analysis. The determined constants are A = 66778.016(12), B = 4463.8489(7), C = 4177.7950(7), Δ J = 0.0015919(5), Δ JK = -0.139214(13), Δ K = 9.4328(18), δJ = 0.0002885(4), δK = 0.03069(4), HJK = -0.817(13) × 10 -6, HKJ = -9.62(4) × 10 -6, HK = 0.00255(8), hJ = 0.0047(3) × 10 -6, in MHz.

  3. Intruder configurations in the ground state of 30Ne

    NASA Astrophysics Data System (ADS)

    Liu, H. N.; Lee, J.; Doornenbal, P.; Scheit, H.; Takeuchi, S.; Aoi, N.; Li, K. A.; Matsushita, M.; Steppenbeck, D.; Wang, H.; Baba, H.; Ideguchi, E.; Kobayashi, N.; Kondo, Y.; Lee, G.; Michimasa, S.; Motobayashi, T.; Poves, A.; Sakurai, H.; Takechi, M.; Togano, Y.; Tostevin, J. A.; Utsuno, Y.

    2017-04-01

    We report on the first detailed study of intruder configurations in the ground state of 30Ne by means of the 12C(30Ne, 29Ne+γ)X one-neutron knockout reaction at 228 MeV/nucleon. Using a combined analysis of individual parallel momentum distributions and partial cross sections we find: (a) comparable p- and d-wave removal strength to 29Ne final states with excitation energies below 200 keV, and (b) significant p-wave removal strength to the 620 keV state of 29Ne, and (c) no evidence for f-wave intruder strength leading to bound 29Ne final states. The SDPF-U-MIX shell model calculation in the sd- pf model space provides a better overall agreement with the measured energy levels of 29Ne and the fp-intruder amplitudes in 30Ne than the SDPF-M prediction, suggesting that the refinement of the sd- pf cross shell interaction and extension of the model space to include the 2p1/2 and 1f5/2 levels are important for understanding the island of inversion.

  4. Ground-State Proton Transfer Kinetics in Green Fluorescent Protein

    PubMed Central

    2015-01-01

    Proton transfer plays an important role in the optical properties of green fluorescent protein (GFP). While much is known about excited-state proton transfer reactions (ESPT) in GFP occurring on ultrafast time scales, comparatively little is understood about the factors governing the rates and pathways of ground-state proton transfer. We have utilized a specific isotopic labeling strategy in combination with one-dimensional 13C nuclear magnetic resonance (NMR) spectroscopy to install and monitor a 13C directly adjacent to the GFP chromophore ionization site. The chemical shift of this probe is highly sensitive to the protonation state of the chromophore, and the resulting spectra reflect the thermodynamics and kinetics of the proton transfer in the NMR line shapes. This information is complemented by time-resolved NMR, fluorescence correlation spectroscopy, and steady-state absorbance and fluorescence measurements to provide a picture of chromophore ionization reactions spanning a wide time domain. Our findings indicate that proton transfer in GFP is described well by a two-site model in which the chromophore is energetically coupled to a secondary site, likely the terminal proton acceptor of ESPT, Glu222. Additionally, experiments on a selection of GFP circular permutants suggest an important role played by the structural dynamics of the seventh β-strand in gating proton transfer from bulk solution to the buried chromophore. PMID:25184668

  5. Ground-state valency and spin configuration of the nickelates.

    NASA Astrophysics Data System (ADS)

    Petit, Leon; Stocks, George M.; Egami, Takeshi; Szotek, Zdzislawa; Temmerman, Walter M.

    2006-03-01

    The ab initio self-interaction-corrected local-spin-density approximation is used to study the electronic structure of both stoichiometric and non-stoichiometric nickelates. From total energy considerations it emerges that, in their ground-state, both LiNiO2, and NaNiO2 are insulators, with the Ni ion in the Ni^3+ low spin state (t2g^6eg^1) configuration. We find that the substitution of Li/Na atoms by divalent impurities, drives an equivalent number of Ni ions in the NiO2 layers from the JT-active trivalent low-spin state to the divalent JT-inactive state. We propose that an experimental study on MgxNa1-xNiO2 might clarify the role of Ni^2+ impurities with respect to the vanishing of long range orbital ordering in Li1-xNi1+xO2. (Work sponsored by the Laboratory Directed Research and Development Program (LDRD) program of ORNL (LP, GMS, TE), and by the DOE-OS through the Offices of Basic Energy Sciences (BES), Division of Materials Sciences and Engineering (LP, GMS, TE). Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the Department of Energy under Contract No. DE-AC05-00OR22725.)

  6. Stability of quantum-dot excited-state laser emission under simultaneous ground-state perturbation

    SciTech Connect

    Kaptan, Y. Herzog, B.; Schöps, O.; Kolarczik, M.; Woggon, U.; Owschimikow, N.; Röhm, A.; Lingnau, B.; Lüdge, K.; Schmeckebier, H.; Arsenijević, D.; Bimberg, D.; Mikhelashvili, V.; Eisenstein, G.

    2014-11-10

    The impact of ground state amplification on the laser emission of In(Ga)As quantum dot excited state lasers is studied in time-resolved experiments. We find that a depopulation of the quantum dot ground state is followed by a drop in excited state lasing intensity. The magnitude of the drop is strongly dependent on the wavelength of the depletion pulse and the applied injection current. Numerical simulations based on laser rate equations reproduce the experimental results and explain the wavelength dependence by the different dynamics in lasing and non-lasing sub-ensembles within the inhomogeneously broadened quantum dots. At high injection levels, the observed response even upon perturbation of the lasing sub-ensemble is small and followed by a fast recovery, thus supporting the capacity of fast modulation in dual-state devices.

  7. Microwave, high-resolution infrared, and quantum chemical investigations of CHBrF2: ground and v4 = 1 states.

    PubMed

    Cazzoli, Gabriele; Cludi, Lino; Puzzarini, Cristina; Stoppa, Paolo; Pietropolli Charmet, Andrea; Tasinato, Nicola; Baldacci, Agostino; Baldan, Alessandro; Giorgianni, Santi; Wugt Larsen, René; Stopkowicz, Stella; Gauss, Jürgen

    2011-02-03

    A combined microwave, infrared, and computational investigation of CHBrF(2) is reported. For the vibrational ground state, measurements in the millimeter- and sub-millimeter-wave regions for CH(79)BrF(2) and CH(81)BrF(2) provided rotational and centrifugal-distortion constants up to the sextic terms as well as the hyperfine parameters (quadrupole-coupling and spin-rotation interaction constants) of the bromine nucleus. The determination of the latter was made possible by recording of spectra at sub-Doppler resolution, achieved by means of the Lamb-dip technique, and supporting the spectra analysis by high-level quantum chemical calculations at the coupled-cluster level. In this context, the importance of relativistic effects, which are of the order of 6.5% and included in the present work using second-order direct perturbation theory, needs to be emphasized for accurate predictions of the bromine quadrupole-coupling constants. The infrared measurements focused on the ν(4) fundamental band of CH(79)BrF(2). Fourier transform investigations using a synchrotron radiation source provided the necessary resolution for the observation and analysis of the rotational structure. The spectroscopic parameters of the v(4) = 1 state were found to be close to those of the vibrational ground state, indicating that the ν(4) band is essentially unaffected by perturbations.

  8. Rotating machinery prognostics: State of the art, challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Heng, Aiwina; Zhang, Sheng; Tan, Andy C. C.; Mathew, Joseph

    2009-04-01

    Machinery prognosis is the forecast of the remaining operational life, future condition, or probability of reliable operation of an equipment based on the acquired condition monitoring data. This approach to modern maintenance practice promises to reduce downtime, spares inventory, maintenance costs, and safety hazards. Given the significance of prognostics capabilities and the maturity of condition monitoring technology, there have been an increasing number of publications on rotating machinery prognostics in the past few years. These publications covered a wide spectrum of prognostics techniques. This review article first synthesises and places these individual pieces of information in context, while identifying their merits and weaknesses. It then discusses the identified challenges, and in doing so, alerts researchers to opportunities for conducting advanced research in the field. Current methods for predicting rotating machinery failures are summarised and classified as conventional reliability models, condition-based prognostics models and models integrating reliability and prognostics. Areas in need of development or improvement include the integration of condition monitoring and reliability, utilisation of incomplete trending data, consideration of effects from maintenance actions and variable operating conditions, derivation of the non-linear relationship between measured data and actual asset health, consideration of failure interactions, practicability of requirements and assumptions, as well as development of performance evaluation frameworks.

  9. Arsenic in ground water of the Western United States

    USGS Publications Warehouse

    Welch, Alan H.; Lico, Michael S.; Hughes, Jennifer L.

    1988-01-01

    Natural occurrences of ground water with moderate (10 to 50 micrograms per liter) to high (greater than 50 micrograms per liter) concentrations of arsenic are common throughout much of the Western United States. High concentrations of arsenic are generally associated with one of four geochemical environments: (1) basin-fill deposits of alluvial-lacustrine origin, particularly in semiarid areas, (2) volcanic deposits, (3) geothermal systems, and (4) uranium and gold-mining areas. These findings are based on an extensive literature review, compilation of unpublished reports and data, and the review of data bases containing more than 7,000 analyses of ground-water samples for arsenic. In the first two environments, arsenic appears to be associated with sediments derived, in part, from volcanic rocks of intermediate to acidic composition. Dissolved arsenic concentrations in water from volcanic aquifers in the same regions, however, may be low (less than 10 micrograms per liter). Solid phases (minerals, amorphous solids, and sedimentary organic matter) that supply the dissolved arsenic have not been identified in most areas. Alluvial and lacustrine sedimentary deposits appear to be an important source of arsenic in volcanic areas (such as Lane County, Oregon) and in areas underlain by basin-fill deposits (such as Carson Desert in Nevada and the Tulare Lake basin in California). Mobilization of arsenic in sedimentary aquifers may be, in part, a result of changes in the geochemical environment due to agricultural irrigation. In the deeper subsurface, elevated arsenic concentrations are associated with compaction caused by groundwater withdrawals.

  10. Ground beetle (Coleoptera: Carabidae) assemblages in the Conservation Reserve Program crop rotation systems in Interior Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult ground beetles (Coleoptera: Carabidae) abundance and diversity were documented on Conservation Research Program (CRP) agricultural lands in Delta Junction, Alaska (64ºN, 145º W). Twenty species were documented based on a total sample of 6,116 specimens collected during 2006 and 2007. Two speci...

  11. Evaluation of rotating-cylinder and piston-cylinder reactors for ground-based emulsion polymerization

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; El-Aasser, M. S.

    1987-01-01

    The objectives of this program are to apply ground-based emulsion polymerization reactor technology to improve the production of: monodisperse latex particles for calibration standards, chromatographic separation column packing, and medical research; and commercial latexes such as those used for coatings, foams, and adhesives.

  12. Periodicity Signatures of Lightcurves of Active Comets in Non-Principal-Axis Rotational States

    NASA Astrophysics Data System (ADS)

    Samarasinha, Nalin H.; Mueller, Beatrice E. A.; Barrera, Jose G.

    2016-10-01

    There are two comets (1P/Halley, 103P/Hartley 2) that are unambiguously in non-principal-axis (NPA) rotational states in addition to a few more comets that are candidates for NPA rotation. Considering this fact, and the ambiguities associated with how to accurately interpret the periodicity signatures seen in lightcurves of active comets, we have started an investigation to identify and characterize the periodicity signatures present in simulated lightcurves of active comets. We carried out aperture photometry of simulated cometary comae to generate model lightcurves and analyzed them with Fourier techniques to identify their periodicity signatures. These signatures were then compared with the input component periods of the respective NPA rotational states facilitating the identification of how these periodicity signatures are related to different component periods of the NPA rotation. Ultimately, we also expect this study to shed light on why only a small fraction of periodic comets is in NPA rotational states, whereas theory indicates a large fraction of them should be in NPA states (e.g., Jewitt 1999, EMP, 79, 35). We explore the parameter space with respect to different rotational states, different orientations for the total rotational angular momentum vector, and different locations on the nucleus for the source region(s). As for special cases, we also investigate potential NPA rotational states representative of comet 103P/Hartley2, the cometary target of the EPOXI mission. The initial results from our investigation will be presented at the meeting. The NASA DDAP Program supports this work through grant NNX15AL66G.

  13. LABS problem and ground state spin glasses system

    NASA Astrophysics Data System (ADS)

    Leukhin, A. N.; Bezrodnyi, V. I.; Kozlova, Yu. A.

    2016-12-01

    In our work we demonstrate the new results of an exhaustive search for optimal binary sequences with minimum peak sidelobe (MPS) up to length N=85. The design problem for law autocorrelation binary sequences (LABS) is a notoriously difficult computational problem which is numbered as the problem number 005 in CSPLib. In statistical physics LABS problem can be interrepted as the energy of N iteracting Ising spins. This is a Bernasconi model. Due to this connection to physics we refer a binary sequence as one-dimensional spin lattice. At this assumption optimal binary sequences by merit factor (MF) criteria are the ground-state spin system without disorder which exhibits a glassy regime.

  14. First resonant tunneling via a light-hole ground state

    NASA Astrophysics Data System (ADS)

    Lampin, J. F.; Mollot, F.

    1998-07-01

    We report the demonstration of resonant tunneling of light-holes through an AlAs/GaAs 0.7P 0.3 double-barrier heterostructure. The tensile strain in the quantum well reverses the order of the light- and heavy-hole levels, the first light-hole level becoming the ground state. The I( V) characteristics are measured at different temperatures and compared to those of a standard AlAs/GaAs unstrained structure. The peak current density of the first light-hole resonance and its peak-to-valley current ratio are enhanced. They reach 28 A/cm 2 and 3.4 : 1 at 15 K. A negative differential resistance is observed up to 250 K.

  15. Tuning the magnetic ground state of a triangular lattice system

    SciTech Connect

    Garlea, Vasile O; Savici, Andrei T; Jin, Rongying

    2011-01-01

    The anisotropic triangular lattice of the crednerite system Cu(Mn$_{1-x}$Cu$_{x}$)O$_{2}$ is used as a basic model for studying the influence of spin disorder on the ground state properties of a two-dimensional frustrated antiferromagnet. Neutron diffraction measurements show that the undoped phase (x=0) undergoes a transition to antiferromagnetic long-range order that is stabilized by a frustration-relieving structural distortion. Small deviation from the stoichiometric composition alters the magnetoelastic characteristics and reduces the effective dimensionality of the magnetic lattice. Upon increasing the doping level, the interlayer coupling changes from antiferromagnetic to ferromagnetic, while the structural distortion is fully suppressed. Concomitantly, the long-range magnetic order is gradually transformed into a two-dimensional order.

  16. Absence of Quantum Time Crystals in Ground States

    NASA Astrophysics Data System (ADS)

    Watanabe, Haruki; Oshikawa, Masaki

    2015-03-01

    In analogy with crystalline solids around us, Wilczek recently proposed the idea of ``time crystals'' as phases that spontaneously break the continuous time translation into a discrete subgroup. The proposal stimulated further studies and vigorous debates whether it can be realized in a physical system. However, a precise definition of the time crystal is needed to resolve the issue. Here we first present a definition of time crystals based on the time-dependent correlation functions of the order parameter. We then prove a no-go theorem that rules out the possibility of time crystals defined as such, in the ground state of a general Hamiltonian which consists of only short-range interactions.

  17. Ground-state correlations within a nonperturbative approach

    NASA Astrophysics Data System (ADS)

    De Gregorio, G.; Herko, J.; Knapp, F.; Lo Iudice, N.; Veselý, P.

    2017-02-01

    The contribution of the two-phonon configurations to the ground state of 4He and 16O is evaluated nonperturbatively using a Hartree-Fock basis within an equation-of-motion phonon method using a nucleon-nucleon optimized chiral potential. Convergence properties of energies and root-mean-square radii versus the harmonic oscillator frequency and space dimensions are investigated. The comparison with the second-order perturbation theory calculations shows that the higher-order terms have an appreciable repulsive effect and yield too-small binding energies and nuclear radii. It is argued that four-phonon configurations, through their strong coupling to two phonons, may provide most of the attractive contribution necessary for filling the gap between theoretical and experimental quantities. Possible strategies for accomplishing such a challenging task are discussed.

  18. a New Phenomenological Formula for Ground-State Binding Energies

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, G.

    A phenomenological formula based on liquid drop model has been proposed for ground-state binding energies of nuclei. The effect due to bunching of single particle levels has been incorporated through a term resembling the one-body Hamiltonian. The effect of n-p interaction has been included through a function of valence nucleons. A total of 50 parameters has been used in the present calculation. The root mean square (r.m.s.) deviation for the binding energy values for 2140 nuclei comes out to be 0.376 MeV, and that for 1091 alpha decay energies is 0.284 MeV. The correspondence with the conventional liquid drop model is discussed.

  19. Rotational bands and isomeric states in 175Lu

    SciTech Connect

    Garrett, P E; Archer, D E; Becker, J A; Bernstein, L A; Hauschild, K; Henry, E A; McNabb, D P; Stoyer, M A; Younes, W; Johns, G D; Nelson, R O; Wilburn, W S

    2003-10-15

    Rotational bands in {sup 175}Lu have been extended through investigation with the (n,n{prime}{gamma}) reaction. Spallation neutrons bombarded Lu samples, and the resulting {gamma} rays were detected in a large-scale Compton-suppressed Ge detector array. Prompt- and delayed-{gamma}{gamma} coincidences have been used to extend most of the existing known bands, and to tentatively assign a new band, based on the 7/2{sup -}[523] configuration, from its band head to spin 13/2. The 3-quasiparticle K{sup {pi}} = 19/2{sup +} isomer is confirmed and its half life determined to be 984 {+-} 13(stat.) {+-} 30(sys.) {micro}s, in agreement with previous results.

  20. Electron excitation from ground state to first excited state: Bohmian mechanics method

    NASA Astrophysics Data System (ADS)

    Yang, Song; Shuang, Zhao; Fu-Ming, Guo; Yu-Jun, Yang; Su-Yu, Li

    2016-03-01

    The excitation process of electrons from the ground state to the first excited state via the resonant laser pulse is investigated by the Bohmian mechanics method. It is found that the Bohmian particles far away from the nucleus are easier to be excited and are excited firstly, while the Bohmian particles in the ground state is subject to a strong quantum force at a certain moment, being excited to the first excited state instantaneously. A detailed analysis for one of the trajectories is made, and finally we present the space and energy distribution of 2000 Bohmian particles at several typical instants and analyze their dynamical process at these moments. Project supported by the Doctoral Research Start-up Funding of Northeast Dianli University, China (Grant No. BSJXM-201332), the National Natural Science Foundation of China (Grant Nos. 11547114, 11534004, 11474129, 11274141, 11447192, and 11304116), and the Graduate Innovation Fund of Jilin University, China (Grant No. 2015091).

  1. Improved finite-source inversion through joint measurements of rotational and translational ground motions: a numerical study

    NASA Astrophysics Data System (ADS)

    Reinwald, Michael; Bernauer, Moritz; Igel, Heiner; Donner, Stefanie

    2016-10-01

    With the prospects of seismic equipment being able to measure rotational ground motions in a wide frequency and amplitude range in the near future, we engage in the question of how this type of ground motion observation can be used to solve the seismic source inverse problem. In this paper, we focus on the question of whether finite-source inversion can benefit from additional observations of rotational motion. Keeping the overall number of traces constant, we compare observations from a surface seismic network with 44 three-component translational sensors (classic seismometers) with those obtained with 22 six-component sensors (with additional three-component rotational motions). Synthetic seismograms are calculated for known finite-source properties. The corresponding inverse problem is posed in a probabilistic way using the Shannon information content to measure how the observations constrain the seismic source properties. We minimize the influence of the source receiver geometry around the fault by statistically analyzing six-component inversions with a random distribution of receivers. Since our previous results are achieved with a regular spacing of the receivers, we try to answer the question of whether the results are dependent on the spatial distribution of the receivers. The results show that with the six-component subnetworks, kinematic source inversions for source properties (such as rupture velocity, rise time, and slip amplitudes) are not only equally successful (even that would be beneficial because of the substantially reduced logistics installing half the sensors) but also statistically inversions for some source properties are almost always improved. This can be attributed to the fact that the (in particular vertical) gradient information is contained in the additional motion components. We compare these effects for strike-slip and normal-faulting type sources and confirm that the increase in inversion quality for kinematic source parameters is

  2. A semiempirical study of the optimized ground and excited state potential energy surfaces of retinal and its protonated Schiff base

    NASA Technical Reports Server (NTRS)

    Parusel, A. B.; Pohorille, A.

    2001-01-01

    The electronic ground and first excited states of retinal and its Schiff base are optimized for the first time using the semiempirical AM1 Hamiltonian. The barrier for rotation about the C(11)-C(12) double bond is characterized by variation of both the twist angle delta(C(10)-C(11)-C(12)-C(13)) and the bond length d(C(11)-C(12)). The potential energy surface is obtained by varying these two parameters. The calculated ground state rotational barrier is equal to 15.6 kcal/mol for retinal and 20.5 kcal/mol for its Schiff base. The all-trans conformation is more stable by 3.7 kcal/mol than the 11-cis geometry. For the first excited state, S(1,) the 90 degrees twisted geometry represents a saddle point for retinal with the rotational barrier of 14.6 kcal/mol. In contrast, this conformation is an energy minimum for the Schiff base. It can be easily reached at room temperature from the planar minima since it is separated from them by a barrier of only 0.6 kcal/mol. The 90 degrees minimum conformation is more stable than the all-trans by 8.6 kcal/mol. We are thus able to present a reaction path on the S(1) surface of the retinal Schiff base with an almost barrier-less geometrical relaxation into a twisted minimum geometry, as observed experimentally. The character of the ground and first excited singlet states underscores the need for the inclusion of double excitations in the calculations.

  3. State-to-state rotational phase coherence effect on the vibration-rotation band shape - An accurate quantum calculation for CO-He

    NASA Technical Reports Server (NTRS)

    Boissoles, J.; Boulet, C.; Robert, D.; Green, S.

    1989-01-01

    Accurate coupled state calculations of line coupling are performed for infrared lines of carbon monoxide perturbed by helium. Such calculations lead to both real and imaginary line couplings. For the first time, the effect of this imaginary line couplings, connected with state-to-state rotational phase coherences, on infrared band shape, is analyzed. An extension of detailed balance principle to the complex plane is suggested from the present computed off-diagonal cross sections. This allows us to understand the physical mechanism underlying the weak effect of phase coherences on CO-He infrared band shape.

  4. Dissociative recombination of the ground state of N2(+)

    NASA Technical Reports Server (NTRS)

    Guberman, Steven L.

    1991-01-01

    Large-scale calculations of the dissociative recombination cross sections and rates for the v = 0 level of the N2(+) ground state are reported, and the important role played by vibrationally excited Rydberg states lying both below and above the v = 0 level of the ion is demonstrated. The large-scale electronic wave function calculations were done using triple zeta plus polarization nuclear-centered-valence Gaussian basis sets. The electronic widths were obtained using smaller wave functions, and the cross sections were calculated on the basis of the multichannel quantum defect theory. The DR rate is calculated at 1.6 x 10 to the -7th x (Te/300) to the -0.37 cu cm/sec for Te in the range of 100 to 1000 K, and is found to be in excellent agreement with prior microwave afterglow experiments but in disagreement with recent merged beam results. It is inferred that the dominant mechanism for DR imparts sufficient energy to the product atoms to allow for escape from the Martian atmosphere.

  5. Tracking the embryonic stem cell transition from ground state pluripotency.

    PubMed

    Kalkan, Tüzer; Olova, Nelly; Roode, Mila; Mulas, Carla; Lee, Heather J; Nett, Isabelle; Marks, Hendrik; Walker, Rachael; Stunnenberg, Hendrik G; Lilley, Kathryn S; Nichols, Jennifer; Reik, Wolf; Bertone, Paul; Smith, Austin

    2017-04-01

    Mouse embryonic stem (ES) cells are locked into self-renewal by shielding from inductive cues. Release from this ground state in minimal conditions offers a system for delineating developmental progression from naïve pluripotency. Here, we examine the initial transition process. The ES cell population behaves asynchronously. We therefore exploited a short-half-life Rex1::GFP reporter to isolate cells either side of exit from naïve status. Extinction of ES cell identity in single cells is acute. It occurs only after near-complete elimination of naïve pluripotency factors, but precedes appearance of lineage specification markers. Cells newly departed from the ES cell state display features of early post-implantation epiblast and are distinct from primed epiblast. They also exhibit a genome-wide increase in DNA methylation, intermediate between early and late epiblast. These findings are consistent with the proposition that naïve cells transition to a distinct formative phase of pluripotency preparatory to lineage priming.

  6. Antiferromagnetic ground state in NpCoGe

    NASA Astrophysics Data System (ADS)

    Colineau, E.; Griveau, J.-C.; Eloirdi, R.; Gaczyński, P.; Khmelevskyi, S.; Shick, A. B.; Caciuffo, R.

    2014-03-01

    NpCoGe, the neptunium analog of the ferromagnetic superconductor UCoGe, has been investigated by dc magnetization, ac susceptibility, specific heat, electrical resistivity, Hall effect, 237Np Mössbauer spectroscopy, and local spin-density approximation (LSDA) calculations. NpCoGe exhibits an antiferromagnetic ground state with a Néel temperature TN≈13 K and an average ordered magnetic moment <μNp>=0.80μB. The magnetic phase diagram has been determined and shows that the antiferromagnetic structure is destroyed by the application of a magnetic field (≈3 T). The value of the isomer shift suggests a Np3+ charge state (configuration 5f4). A high Sommerfeld coefficient value for NpCoGe (170 mJ mol-1 K-2) is inferred from specific heat. LSDA calculations indicate strong magnetic anisotropy and easy magnetization along the c axis. Mössbauer data and calculated exchange interactions support the possible occurrence of an elliptical spin-spiral structure in NpCoGe. The comparison with NpRhGe and uranium analogs suggests the leading role of 5f-d hybridization, the rather delocalized character of 5f electrons in NpCoGe, and the possible proximity of NpRuGe or NpFeGe to a magnetic quantum critical point.

  7. Ground state and resonant states of helium in exponential cosine screened Coulomb potential

    NASA Astrophysics Data System (ADS)

    Ghoshal, Arijit; Ho, Y. K.

    2009-05-01

    We have investigated the ground state and a resonance state of normal helium atom in exponential cosine screened Coulomb potential (ECSCP) with screening parameterλ: V(r),,,1r,^-λr(λr) (in a.u.), where r denotes the inter-particle distance. Within the framework of Ritz's variational principle and making use of a highly correlated wave function, we have determined the ground state energies and wave functions of the helium atom for different values of the screening parameterλ. Furthermore, we have shown that the ground state energy of helium for a particular value of λ does converge with increasing number of terms in the wave function. In addition, using the stabilization method, we have investigated the doubly excited 2s^2 ^1S^e resonance state in helium with ECSCP. Resonance energy and width for various λ values are calculated. Our present work will play a useful role in the investigations of atomic structures in quantum plasmas [1]. [1]. P.K. Shukla and B. Eliasson, Phys. Lett. A 372, 2899 (2008).

  8. Collisional metastability of high rotational states of CN(X 2Σ +, ? = 0)

    NASA Astrophysics Data System (ADS)

    Hay, S.; Shokoohi, F.; Callister, S.; Wittig, C.

    1985-07-01

    CN(X 2Σ +, v'' = 0) high rotational states relax slowly via 300 K collisions with Ar and Kr. Relaxation decreases with increasing rotation, and the partially relaxed distributions are bimodal, with low N'' thermalized (300 K), and N'' = 80 unrelaxed after 1000 collisions. Relaxation by N 2, CO, and Xe is similar to Ar and Kr, but more efficient. He and NO remove many quanta in a single collision.

  9. A semiempirical study for the ground and excited states of free-base and zinc porphyrin-fullerene dyads

    NASA Technical Reports Server (NTRS)

    Parusel, A. B.

    2000-01-01

    The ground and excited states of a covalently linked porphyrin-fullerene dyad in both its free-base and zinc forms (D. Kuciauskas et al., J. Phys. Chem. 100 (1996) 15926) have been investigated by semiempirical methods. The excited-state properties are discussed by investigation of the character of the molecular orbitals. All frontier MOs are mainly localized on either the donor or the acceptor subunit. Thus, the absorption spectra of both systems are best described as the sum of the spectra of the single components. The experimentally observed spectra are well reproduced by the theoretical computations. Both molecules undergo efficient electron transfer in polar but not in apolar solvents. This experimental finding is explained theoretically by explicitly considering solvent effects. The tenth excited state in the gas phase is of charge-separated character where an electron is transferred from the porphyrin donor to the fullerene acceptor subunit. This state is stabilized in energy in polar solvents due to its large formal dipole moment. The stabilization energy for an apolar environment such as benzene is not sufficient to lower this state to become the first excited singlet state. Thus, no electron transfer is observed, in agreement with experiment. In a polar environment such as acetonitrile, the charge-separated state becomes the S, state and electron transfer takes place, as observed experimentally. The flexible single bond connecting both the donor and acceptor subunits allows free rotation by ca. +/- 30 degrees about the optimized ground-state conformation. For the charge-separated state this optimized geometry has a maximum dipole moment. The geometry of the charge-separated state thus does not change relatively to the ground-state conformation. The electron-donating properties of porphyrin are enhanced in the zinc derivative due to a reduced porphyrin HOMO-LUMO energy gap. This yields a lower energy for the charge-separated state compared to the free

  10. Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor.

    PubMed

    Rodrigues, Michael L M; Leão, Versiane A; Gomes, Otavio; Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan

    2015-07-01

    The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (-208μm+147μm), ferrous iron concentration (1.25-10.0g/L) and pH (1.5-2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20mm-long) working with increased solids concentration (up to 25.0g/L). Because there was as the faster leaching kinetics at 50°C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8days and microscopic observations by SEM-EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20mm-size sheets.

  11. Analysis of the Rotational Structure of ˜{B}^2A' ← ˜{X}^2A' Transition of Isopropoxy Radical: Isolated State vs. Coupled States Model

    NASA Astrophysics Data System (ADS)

    Melnik, Dmitry G.; Miller, Terry A.; Liu, Jinjun

    2013-06-01

    Isopropoxy radicals are reactive intermediates in atmospheric and combustion chemistry. From the theoretical point of view, they represent an extreme case of ``isotopically'' substituted methoxy radicals with two methyl groups playing the role of heavy hydrogen isotopes. Previously the rotationally resolved spectra of ˜{B}^2A' ← ˜{X}^2A' electronic transition were successfully analyzed using a simple effective rotational Hamiltonian of the isolated ˜{X} and ˜{B} states. However, a number of the experimentally determined parameters appeared dramatically inconsistent with the quantum chemistry calculations and theoretical predictions based on the symmetry arguments. Recently, we analyzed these spectra using a coupled two state model, which explicitly includes interactions between the ground ˜{X}^2A' state and low-lying excited ˜{A}^2A^'' state. In this presentation we will discuss the results of this analysis and compare the parameters of both models and their physical significance. D. G. Melnik, T. A. Miller and J. Liu, TI15, 67^{th Molecular Spectroscopy Symposium}, Columbus, 2012

  12. Millimeter Wave Spectra of the Internal Rotation Excited States of (o)H_2-H_2O and (o)H_2-D_2O

    NASA Astrophysics Data System (ADS)

    Harada, K.; Iwasaki, Y.; Giesen, T.; Tanaka, K.

    2013-06-01

    H_2-H_2O is a weakly bound complex and it has a various states according to the internal rotation for both H_2 and H_2O moieties. In our previous study, we have reported the pure rotational transitions of the (o)H_2 complex in the ground H_2O rotational state, 0_{00}(Σ), for both H_2-H_2O and H_2-D_2O, where (o)H_2 (j_{ H2} =1) is rotating perpendicular to the intermolecular axis to give the projection of j_{ H2} to the axis k_{ H2} to be zero (i.e. Σ state). In the present study, we have observed the rotational transitions for the 0_{00} (Π) states in the millimeter-wave region up to 220 GHz, where the (o)H_2 is rotating around the intermolecular axis to give the projection k_{ H2} to be one (i.e. Π state). The center of mass bond lengths derived from the observed rotational constants for 0_{00} (Π) are longer by 5 % than those for 0_{00} (Σ), while force constants for the intermolecular stretching for 0_{00} (Π) derived from centrifugal distortion constants are smaller by 23 % than those for 0_{00} (Σ), suggesting the Π and Σ substates have quite different structures. The recent theoretical calculation indicates that for 0_{00}(Σ), (o)H_2 is bound to the oxygen site of H_2O, while for the 0_{00} (Π) state, (o)H_2 to the hydrogen site of H_2O, and the 0_{00}(Σ) state is by 14 cm^{-1} more stable than the 0_{00} (Π) state. Observed molecular constants for 0_{00}(Σ) and (Π) are consistent with the structures given by the theoretical calculation. We also observed the rotational spectrum in the 1_{01} (Σ) and (Π) states, where Σ and Π correspond to the rotation of H_2O perpendicular and parallel to the intermolecular axis and (o)H_2 is calculated to be bound to the oxygen site of H_2O. The energy difference between the 1_{01} (Σ) and (Π) states will be discussed due to the Criolis interaction between these substates. C. J. Whitham, K. Tanaka, and K. Harada, The 56th OSU Symposium, RD08 (2001). Ad. van der Avoid and D. J. Nesbit, J. Chem. Phys

  13. Arsenic in Ground-Water Resources of the United States

    USGS Publications Warehouse

    Welch, Alan H.; Watkins, Sharon A.; Helsel, Dennis R.; Focazio, Michael J.

    2000-01-01

    Arsenic is a naturally occurring element in rocks, soils, and the waters in contact with them. Recognized as a toxic element for centuries, arsenic today also is a human health concern because it can contribute to skin, bladder, and other cancers (National Research Council, 1999). Recently, the National Research Council (1999) recommended lowering the current maximum contaminant level (MCL) allowed for arsenic in drinking water of 50 ?g/L (micrograms per liter), citing risks for developing bladder and other cancers. The U.S. Environmental Protection Agency (USEPA) will propose a new, and likely lower, arsenic MCL during 2000 (U.S. Environmental Protection Agency, 2000). This fact sheet provides information on where and to what extent natural concentrations of arsenic in ground water exceed possible new standards. The U.S. Geological Survey (USGS) has collected and analyzed arsenic in potable (drinkable) water from 18,850 wells in 595 counties across the United States during the past two decades. These wells are used for irrigation, industrial purposes, and research, as well as for public and private water supply. Arsenic concentrations in samples from these wells are similar to those found in nearby public supplies (see Focazio and others, 1999). The large number of samples, broad geographic coverage, and consistency of methods produce a more accurate and detailed picture of arsenic concentrations than provided by any previous studies.

  14. Ground-state properties of neutron-rich Mg isotopes

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Minomo, K.; Shimada, M.; Tagami, S.; Kimura, M.; Takechi, M.; Fukuda, M.; Nishimura, D.; Suzuki, T.; Matsumoto, T.; Shimizu, Y. R.; Yahiro, M.

    2014-04-01

    We analyze recently measured total reaction cross sections for 24-38Mg isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics (AMD). The folding model well reproduces the measured reaction cross sections, when the projectile densities are evaluated by the deformed Woods-Saxon (def-WS) model with AMD deformation. Matter radii of 24-38Mg are then deduced from the measured reaction cross sections by fine tuning the parameters of the def-WS model. The deduced matter radii are largely enhanced by nuclear deformation. Fully microscopic AMD calculations with no free parameter well reproduce the deduced matter radii for 24-36Mg, but still considerably underestimate them for 37,38Mg. The large matter radii suggest that 37,38Mg are candidates for deformed halo nucleus. AMD also reproduces other existing measured ground-state properties (spin parity, total binding energy, and one-neutron separation energy) of Mg isotopes. Neutron-number (N) dependence of deformation parameter is predicted by AMD. Large deformation is seen from 31Mg with N =19 to a drip-line nucleus 40Mg with N =28, indicating that both the N =20 and 28 magicities disappear. N dependence of neutron skin thickness is also predicted by AMD.

  15. New Ground-State Crystal Structure of Elemental Boron

    NASA Astrophysics Data System (ADS)

    An, Qi; Reddy, K. Madhav; Xie, Kelvin Y.; Hemker, Kevin J.; Goddard, William A.

    2016-08-01

    Elemental boron exhibits many polymorphs in nature based mostly on an icosahedral shell motif, involving stabilization of 13 strong multicenter intraicosahedral bonds. It is commonly accepted that the most thermodynamic stable structure of elemental boron at atmospheric pressure is the β rhombohedral boron (β -B ). Surprisingly, using high-resolution transmission electron microscopy, we found that pure boron powder contains grains of two different types, the previously identified β -B containing a number of randomly spaced twins and what appears to be a fully transformed twinlike structure. This fully transformed structure, denoted here as τ -B , is based on the C m c m orthorhombic space group. Quantum mechanics predicts that the newly identified τ -B structure is 13.8 meV /B more stable than β -B . The τ -B structure allows 6% more charge transfer from B57 units to nearby B12 units, making the net charge 6% closer to the ideal expected from Wade's rules. Thus, we predict the τ -B structure to be the ground state structure for elemental boron at atmospheric pressure.

  16. Ground-state coding in partially connected neural networks

    NASA Technical Reports Server (NTRS)

    Baram, Yoram

    1989-01-01

    Patterns over (-1,0,1) define, by their outer products, partially connected neural networks, consisting of internally strongly connected, externally weakly connected subnetworks. The connectivity patterns may have highly organized structures, such as lattices and fractal trees or nests. Subpatterns over (-1,1) define the subcodes stored in the subnetwork, that agree in their common bits. It is first shown that the code words are locally stable stares of the network, provided that each of the subcodes consists of mutually orthogonal words or of, at most, two words. Then it is shown that if each of the subcodes consists of two orthogonal words, the code words are the unique ground states (absolute minima) of the Hamiltonian associated with the network. The regions of attraction associated with the code words are shown to grow with the number of subnetworks sharing each of the neurons. Depending on the particular network architecture, the code sizes of partially connected networks can be vastly greater than those of fully connected ones and their error correction capabilities can be significantly greater than those of the disconnected subnetworks. The codes associated with lattice-structured and hierarchical networks are discussed in some detail.

  17. Table of experimental nuclear ground state charge radii: An update

    SciTech Connect

    Angeli, I.; Marinova, K.P.

    2013-01-15

    The present table contains experimental root-mean-square (rms) nuclear charge radii R obtained by combined analysis of two types of experimental data: (i) radii changes determined from optical and, to a lesser extent, K{sub α} X-ray isotope shifts and (ii) absolute radii measured by muonic spectra and electronic scattering experiments. The table combines the results of two working groups, using respectively two different methods of evaluation, published in ADNDT earlier. It presents an updated set of rms charge radii for 909 isotopes of 92 elements from {sub 1}H to {sub 96}Cm together, when available, with the radii changes from optical isotope shifts. Compared with the last published tables of R-values from 2004 (799 ground states), many new data are added due to progress recently achieved by laser spectroscopy up to early 2011. The radii changes in isotopic chains for He, Li, Be, Ne, Sc, Mn, Y, Nb, Bi have been first obtained in the last years and several isotopic sequences have been recently extended to regions far off stability, (e.g., Ar, Mo, Sn, Te, Pb, Po)

  18. Local reversibility and entanglement structure of many-body ground states

    NASA Astrophysics Data System (ADS)

    Kuwahara, Tomotaka; Arad, Itai; Amico, Luigi; Vedral, Vlatko

    2017-03-01

    The low-temperature physics of quantum many-body systems is largely governed by the structure of their ground states. Minimizing the energy of local interactions, ground states often reflect strong properties of locality such as the area law for entanglement entropy and the exponential decay of correlations between spatially separated observables. Here, we present a novel characterization of quantum states, which we call ‘local reversibility’. It characterizes the type of operations that are needed to reverse the action of a general disturbance on the state. We prove that unique ground states of gapped local Hamiltonian are locally reversible. This way, we identify new universal features of many-body ground states, which cannot be derived from the aforementioned properties. We use local reversibility to distinguish between states enjoying microscopic and macroscopic quantum phenomena. To demonstrate the potential of our approach, we prove specific properties of ground states, which are relevant both to critical and non-critical theories.

  19. Effect of the equation of state on the maximum mass of differentially rotating neutron stars

    NASA Astrophysics Data System (ADS)

    Studzińska, A. M.; Kucaba, M.; Gondek-Rosińska, D.; Villain, L.; Ansorg, M.

    2016-12-01

    Knowing the value of the maximum mass of a differentially rotating relativistic star is a key step towards the understanding of the signals to be expected from the merger of binary neutron stars, one of the most awaited alternative sources of gravitational waves after binary black holes. In this paper, we study the effects of differential rotation and of the equation of state on the maximum mass of rotating neutron stars modelled as relativistic polytropes with various adiabatic indices. Calculations are performed using a highly accurate numerical code, based on a multidomain spectral method. We thoroughly explore the parameter space and determine how the maximum mass depends on the stiffness, on the degree of differential rotation and on the maximal density, taking into account all the types of solutions that were proven to exist in a preceding paper. The highest increase with respect to the maximum mass for non-rotating stars with the same equation of state is reached for a moderate stiffness. With differential rotation, the maximum mass can even be 3-4 times higher than it is for static stars. This result may have important consequences for the gravitational wave signal from coalescing neutron star binaries or for some supernovae events.

  20. Ground-State SiO Maser Emission Toward Evolved Stars

    DTIC Science & Technology

    2006-05-31

    emulateapj v. 11/12/01 GROUND-STATE SIO MASER EMISSION TOWARD EVOLVED STARS D. A. BOBOLTZ U.S. Naval Observatory, 3450 Massachusetts Ave., NW...Accepted by the Astrophysical Journal 2004 February 20 ABSTRACT We have made the first unambiguous detection of vibrational ground-state maser emission ...observed. Ground-state thermal emission was detected for one of the stars, RX Boo, with a peak brightness temperature of 200 K. Comparing the v = 0 and

  1. Exploring ground states and excited states of spin-1 Bose-Einstein condensates by continuation methods

    SciTech Connect

    Chen, Jen-Hao; Chern, I-Liang; Wang Weichung

    2011-03-20

    A pseudo-arclength continuation method (PACM) is employed to compute the ground state and excited state solutions of spin-1 Bose-Einstein condensates (BEC). The BEC is governed by the time-independent coupled Gross-Pitaevskii equations (GPE) under the conservations of the mass and magnetization. The coupling constants that characterize the spin-independent and spin-exchange interactions are chosen as the continuation parameters. The continuation curve starts from a ground state or an excited state with very small coupling parameters. The proposed numerical schemes allow us to investigate the effect of the coupling constants and study the bifurcation diagrams of the time-independent coupled GPE. Numerical results on the wave functions and their corresponding energies of spin-1 BEC with repulsive/attractive and ferromagnetic/antiferromagnetic interactions are presented. Furthermore, we reveal that the component separation and population transfer between the different hyperfine states can only occur in excited states due to the spin-exchange interactions.

  2. Pure quantum states of a neutrino with rotating spin in dense magnetized matter

    NASA Astrophysics Data System (ADS)

    Arbuzova, E. V.; Lobanov, A. E.; Murchikova, E. M.

    2010-02-01

    The problem of neutrino spin rotation in dense matter and in strong electromagnetic fields is solved in accordance with the basic principles of quantum mechanics. We obtain a complete system of wave functions for a massive Dirac neutrino with an anomalous magnetic moment which are the eigenfunctions of the kinetic momentum operator and have the form of nonspreading wave packets. These wave functions enable one to consider the states of neutrino with rotating spin as pure quantum states and can be used for calculating probabilities of various processes with the neutrino in the framework of the Furry picture.

  3. A ground state depleted laser in neodymium doped yttrium orthosilicate

    SciTech Connect

    Beach, R.; Albrecht, G.; Solarz, R.; Krupke, W.; Comaskey, B.; Mitchell, S.; Brandle, C.; Berkstresser, G.

    1990-01-16

    A ground state depleted (GSD){sup 1,2} laser has been demonstrated in the form of a Q-switched oscillator operating at 912 nm. Using Nd{sup 3+} as the active ion and Y{sub 2}SiO{sub 5} as the host material, the laser transition is from the lowest lying stark level of the Nd{sup 3t}F{sub 3/2} level to a stark level 355 cm{sup {minus}1} above the lowest lying one in the {sup 4}I{sub 9/2} manifold. The necessity of depleting the ground {sup 4}I{sub 9/2} manifold is evident for this level scheme as transparency requires a 10% inversion. To achieve the high excitation levels required for the efficient operation of this laser, bleach wave pumping using an alexandrite laser at 745 nm has been employed. The existence of a large absorption feature at 810 nm also allows for the possibility of AlGaAs laser diode pumping. Using KNbO{sub 3}, noncritical phase matching is possible at 140{degree}C using d{sub 32} and has been demonstrated. The results of Q-switched laser performance and harmonic generation in KNbO{sub 3} will be presented. Orthosilicate can be grown in large boules of excellent optical quality using a Czochralski technique. Because of the relatively small 912 nm emission cross section of 2-3 {times} 10{sup {minus}20} cm{sup 2} (orientation dependent) fluences of 10-20 J/cm{sup 2} must be circulated in the laser cavity for the efficient extraction of stored energy. This necessitates very aggressive laser damage thresholds. Results from the Reptile laser damage facility at Lawrence Livermore National Laboratory (LLNL) will be presented showing Y{sub 2}SiO{sub 5} bulk and AR sol-gel coated surface damage thresholds of greater than 40 J/cm{sup 2} for 10 nsec, 10 Hz, 1.06 {mu} pulses. 16 refs., 18 figs., 6 tabs.

  4. Lower bounds for the ground-state degeneracies of frustrated systems on fractal lattices

    PubMed

    Curado; Nobre

    2000-12-01

    The total number of ground states for nearest-neighbor-interaction Ising systems with frustrations, defined on hierarchical lattices, is investigated. A simple method is presented, which allows one to factorize the ground-state degeneracy, at a given hierarchy level n, in terms of contributions due to all hierarchy levels. Such a method may yield the exact ground-state degeneracy of uniformly frustrated systems, whereas it works as an approximation for randomly frustrated models. In the latter cases, it is demonstrated that such an approximation yields lower-bound estimates for the ground-state degeneracies.

  5. Electronic ground state OH(X) radical in a low-temperature atmospheric pressure plasma jet

    NASA Astrophysics Data System (ADS)

    Fuh, Che A.; Clark, Shane M.; Wu, Wei; Wang, Chuji

    2016-10-01

    The wide applicability of atmospheric pressure plasma jets in biomedicine stems from the presence of reactive nitrogen and oxygen species generated in these plasma jets. Knowing the absolute concentration of these reactive species is of utmost importance as it is critical, along with the particle flux obtained from the plasma feed gas flow rate to ensure that the correct dosage is applied during applications. In this study, we investigate and report the ground state OH(X) number density acquired using cavity ringdown spectroscopy, along the propagation axis (z-axis) of a cold atmospheric pressure helium plasma plume. The jet was generated by a repetitively pulsed mono-polar square wave of duration 1 μs running at a frequency of 9.9 kHz. The voltage supplied was 6.5 kV with the helium flow rate fixed at 3.6 standard liters per minute. The rotational and vibrational temperatures are simulated from the second positive system of nitrogen, N 2(C3πu-B3πg) , with the rotational temperature being spatially constant at 300 K along the propagation axis of the atmospheric pressure plasma jet while the vibrational temperature is 3620 K at the beginning of the plume and is observed to decrease downstream. The OH(A) emission intensity obtained via optical emission spectroscopy was observed to decrease downstream of the plasma jet. The OH(X) number density along the propagation axis was initially 2.2 × 1013 molecules cm-3 before increasing to a peak value of 2.4 × 1013 molecules cm-3, from which the number density was observed to decrease to 2.2 × 1013 molecules cm-3 downstream of the plasma jet. The total OH(A, X) in the plasma jet remained relatively constant along the propagation axis of the plasma jet before falling off at the tip of the jet. The increase in vibrational temperature downstream and the simultaneous measurements of both the excited state OH(A) and the ground state OH(X) reported in this study provide insights into the formation and consumption of this

  6. Ground Water Quality Protection. State and Local Strategies.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Commission on Physical Sciences, Mathematics, and Resources.

    Using regional case studies, this document examines representative programs for dealing with ground water contamination. Section one describes the ground water protection strategy of the U.S. Environmental Protection Agency (EPA); (2) discusses the limited data available for determining the extent of contamination; (3) provides a listing of the…

  7. Derivation of novel human ground state naive pluripotent stem cells.

    PubMed

    Gafni, Ohad; Weinberger, Leehee; Mansour, Abed AlFatah; Manor, Yair S; Chomsky, Elad; Ben-Yosef, Dalit; Kalma, Yael; Viukov, Sergey; Maza, Itay; Zviran, Asaf; Rais, Yoach; Shipony, Zohar; Mukamel, Zohar; Krupalnik, Vladislav; Zerbib, Mirie; Geula, Shay; Caspi, Inbal; Schneir, Dan; Shwartz, Tamar; Gilad, Shlomit; Amann-Zalcenstein, Daniela; Benjamin, Sima; Amit, Ido; Tanay, Amos; Massarwa, Rada; Novershtern, Noa; Hanna, Jacob H

    2013-12-12

    Mouse embryonic stem (ES) cells are isolated from the inner cell mass of blastocysts, and can be preserved in vitro in a naive inner-cell-mass-like configuration by providing exogenous stimulation with leukaemia inhibitory factor (LIF) and small molecule inhibition of ERK1/ERK2 and GSK3β signalling (termed 2i/LIF conditions). Hallmarks of naive pluripotency include driving Oct4 (also known as Pou5f1) transcription by its distal enhancer, retaining a pre-inactivation X chromosome state, and global reduction in DNA methylation and in H3K27me3 repressive chromatin mark deposition on developmental regulatory gene promoters. Upon withdrawal of 2i/LIF, naive mouse ES cells can drift towards a primed pluripotent state resembling that of the post-implantation epiblast. Although human ES cells share several molecular features with naive mouse ES cells, they also share a variety of epigenetic properties with primed murine epiblast stem cells (EpiSCs). These include predominant use of the proximal enhancer element to maintain OCT4 expression, pronounced tendency for X chromosome inactivation in most female human ES cells, increase in DNA methylation and prominent deposition of H3K27me3 and bivalent domain acquisition on lineage regulatory genes. The feasibility of establishing human ground state naive pluripotency in vitro with equivalent molecular and functional features to those characterized in mouse ES cells remains to be defined. Here we establish defined conditions that facilitate the derivation of genetically unmodified human naive pluripotent stem cells from already established primed human ES cells, from somatic cells through induced pluripotent stem (iPS) cell reprogramming or directly from blastocysts. The novel naive pluripotent cells validated herein retain molecular characteristics and functional properties that are highly similar to mouse naive ES cells, and distinct from conventional primed human pluripotent cells. This includes competence in the generation

  8. E2 transitions between excited single-phonon states: Role of ground-state correlations

    NASA Astrophysics Data System (ADS)

    Kamerdzhiev, S. P.; Voitenkov, D. A.

    2016-11-01

    The probabilities for E2 transitions between low-lying excited 3- and 5- single-phonon states in the 208Pb and 132Sn magic nuclei are estimated on the basis of the theory of finite Fermi systems. The approach used involves a new type of ground-state correlations, that which originates from integration of three (rather than two, as in the random-phase approximation) single-particle Green's functions. These correlations are shown to make a significant contribution to the probabilities for the aforementioned transitions.

  9. Infrared and far-infrared laser magnetic resonance spectroscopy of the GeH radical - Determination of ground state parameters

    NASA Technical Reports Server (NTRS)

    Brown, J. M.; Evenson, K. M.; Sears, T. J.

    1985-01-01

    The GeH radical has been detected in its ground 2 Pi state in the gas phase reaction of fluorine atoms with GeH4 by laser magnetic resonance techniques. Rotational transitions within both 2 Pi 1/2 and 2 Pi 3/2 manifolds have been observed at far-infrared wavelengths and rotational transitions between the two fine structure components have been detected at infrared wavelengths (10 microns). Signals have been observed for all five naturally occurring isotopes of germanium. Nuclear hyperfine structure for H-1 and Ge-73 has also been observed. The data for the dominant isotope (/Ge-74/H) have been fitted to within experimental error by an effective Hamiltonian to give a set of molecular parameters for the X 2 Pi state which is very nearly complete. In addition, the dipole moment of GeH in its ground state has been estimated from the relative intensities of electric and magnetic dipole transitions in the 10 micron spectrum to be 1.24(+ or - 0.10) D.

  10. Spectral Assignments and Analysis of the Ground State of Nitromethane in High-Resolution FTIR Synchrotron Spectra

    NASA Astrophysics Data System (ADS)

    Twagirayezu, Sylvestre; Billinghurst, Brant E.; May, Tim E.; Dawadi, Mahesh B.; Perry, David S.

    2014-06-01

    The Fourier Transform infrared spectra of CH3NO2, have been recorded, in the 400-950 wn spectral region, at a resolution of 0.00096 wn, using the Far-Infrared Beamline at Canadian Light Source. The observed spectra contain four fundamental vibrations: the NO2 in-plane rock (475.2 wn), the NO2 out-of-plane rock (604.9 wn), the NO2 symmetric bend (657.1 wn), and the CN-stretch (917.2 wn). For the lowest torsional state of CN-stretch and NO2 in-plane rock, transitions involving quantum numbers, " = 0; " {≤ 50} and {_a}" {≤ 10}, have been assigned with the aid of an automated ground state combination difference program together with a traditional Loomis Wood approach Ground state combination differences derived from more than 2100 infrared transitions have been fit with the six-fold torsion-rotation program developed by Ilyushin et al. Additional sextic and octic centrifugal distortion parameters are derived for the ground vibrational state. C. F. Neese., An Interactive Loomis-Wood Package, V2.0, {56th},OSU Interanational Symposium on Molecular Spectroscopy (2001). V. V. Ilyushin, Z. Kisiel, L. Pszczolkowski, H. Mader, and J. T. Hougen, J. Mol. Spectrosc., 259, 26, (2010).

  11. The H 2O ++ Ground State Potential Energy Surface

    NASA Astrophysics Data System (ADS)

    Bunker, P. R.; Bludsky, Ota; Jensen, Per; Wesolowski, S. S.; Van Huis, T. J.; Yamaguchi, Y.; Schaefer, H. F.

    1999-12-01

    At the correlation-consistent polarized-valence quadruple-zeta complete active space self-consistent field second-order configuration interaction level of ab initio theory (cc-pVQZ CASSCF-SOCI), we calculated 129 points on the ground electronic state potential energy surface of the water dication H2O++; this calculation includes the energy of X3Σ- OH+ at equilibrium and the energy of the triplet oxygen atom. We determined the parameters in an analytical function that represents this surface out to the (OH+ + H+) and (O + 2H+) dissociation limits, for bending angles from 70 to 180°. There is a metastable minimum in this surface, at an energy of 43 600 cm-1 above the H+ + OH+ dissociation energy, and the geometry at this minimum is linear (D∞h), with an OH bond length of 1.195 Å. On the path to dissociation to H+ + OH+, there is a saddle point at an energy of 530 cm-1 above the minimum, and the geometry at the saddle point is linear (C∞ Kv) with OH bond lengths of 1.121 and 1.489 Å. Using the stabilization method, we calculated the lowest resonance on this surface. Relative to the metastable local minimum on the potential energy surface, the position of the lowest resonance for H2O++, D2O++, and T2O++ is 1977(85), 1473(25), and 1249(10) cm-1, respectively, where the width of each resonance (in cm-1) is given in parentheses.

  12. The determination of Mercury's gravity field and rotational state with the mission BepiColombo

    NASA Astrophysics Data System (ADS)

    Iess, L.; Asmar, S. W.; Milani, A.; Tortora, P.; Iafolla, V.

    Gravity field and rotational state provide accurate constraints to geophysical models of planetary interiors and have been therefore a major source of information on the internal structure of solar system bodies. Their determination is particularly important for Mercury, whose interior is the least known among terrestrial planets. Today, planetary gravity fields are best investigated by means of microwave Doppler tracking of orbiting spacecraft. In order to attain precise measurements the radio link (involving a carrier transmitted from ground to the spacecraft and retransmitted back to ground) must preserve the highest phase stability and coherence at each intervening stage. Electronic noise from ground and onboard instrumentation must be minimized and propagation noise (due to plasma and troposphere) must be kept to a minimum. This is especially important for phase instabilities induced by interplanetary plasma and solar corona, which have been the main limitation in past gravity experiments with planetary probes. Both forthcoming space missions to Mercury (NASA's Messenger and ESA's Bepi- Colombo) host radio science investigations devoted to geodesy and geophysics. While Messenger's experiment exploits the onboard telecommunication system, based upon a X-band radio link (7.1-8.4 GHz), the experiment MORE (Mercury Orbiter Radioscience Experiment) of BepiColombo makes use of a Ka-band radio link (32-34 GHz) enabled by dedicated onboard and ground hardware. The use of a Ka-band link in combination with the standard telecommunication system allows a complete cancellation of the plasma noise and two-way range rate measurements as accurate as 3 micron/s over time scales of 1000 s, independently of the solar elongation angle. The radio instrumentation includes also a wide-band ranging system (WBRS, using a 20 MHz tone) with a target two-way accuracy of 20 cm. The ranging system will be used to determine Mercury's orbit in the solar system, carrying out accurate tests

  13. Simultaneous Evaluation of Multiple Rotationally Excited States of Floppy Molecules Using Diffusion Monte Carlo

    NASA Astrophysics Data System (ADS)

    McCoy, Anne B.; Ford, Jason E.; Marlett, Melanie L.; Petit, Andrew S.

    2014-06-01

    In this work, an extension to diffusion Monte Carlo (DMC) is proposed, allowing for the simultaneous calculation of the energy and wave function of multiple rotationally excited states of floppy molecules. The total wave function is expanded into a set of Dirac δ-functions called walkers, while the rotational portion of the wave function is expanded in a symmetric top basis set. Each walker is given a rotational state vector containing coefficients for all states of interest. The positions of the atoms and the coefficients in the state vector evolve according to the split operator approximation of the quantum propagator. The method was benchmarked by comparing calculated rotation-vibration energies for H_3^+, H_2D^+, and H_3O^+ to experimental values. For low to moderate values of J, the resulting energies are within the statistical uncertainty of the calculation. Rotation-vibration coupling is captured through flexibility introduced in the form of the vibrational wave function. This coupling is found to increase with increasing J-values. Based on the success achieved through these systems, the method was applied to CH_5^+ and its deuterated isotopologues for v = 0, J ≥ 10. Based on these calculations, the energy level structure of CH_5^+ is found to resemble that for a of a spherical top, and excitations up to J = 10 displayed insignificant rotation-vibration coupling. Extensions of this approach that explicitly account for vibrations will also be discussed. ` A. S. Petit, J. E. Ford and A. B. McCoy, J. Phys. Chem. A, in press, K. D. Jordan Festschrift, DOI: 10.1021/jp408821a

  14. Far-Infrared Rotational and Fine-Structure Transition Frequencies and Molecular Constants of 14NO and 15NO in the X2Pi (v = 0) State.

    PubMed

    Varberg; Stroh; Evenson

    1999-07-01

    We have made highly accurate measurements of the absorption spectrum of the 14NO and 15NO isotopomers of nitric oxide in the far-infrared. Pure rotational transitions up to J" = 3712 within the 2Pi1/2 and 2Pi3/2 spin components and several 2Pi3/2 <-- 2Pi1/2 fine-structure transitions were recorded within the ground vibrational state. A least-squares fit to these data combined with some lambda-doubling and rotational transitions measured by previous workers has resulted in accurate values for the rotational, fine, and hyperfine parameters of these two isotopomers. Most of the far-infrared transitions reported here have an experimental uncertainty of about 20 kHz and will be useful for astronomers and atmospheric scientists studying this important molecule. The more accurate calculated frequencies will also be useful as spectroscopic calibration standards. Copyright 1999 Academic Press.

  15. Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor

    SciTech Connect

    Rodrigues, Michael L.M.; Leão, Versiane A.; Gomes, Otavio; Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan

    2015-07-15

    Highlights: • Copper bioleaching from PCB (20 mm) by moderate thermophiles was demonstrated. • Larger PCB sheets enable a cost reduction due to the elimination of fine grinding. • Crushing generated cracks in PCB increasing the copper extraction. • A pre-treatment step was necessary to remove the lacquer coating. • High copper extractions (85%) were possible with pulp density of up to 25.0 g/L. - Abstract: The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (−208 μm + 147 μm), ferrous iron concentration (1.25–10.0 g/L) and pH (1.5–2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0 g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20 mm-long) working with increased solids concentration (up to 25.0 g/L). Because there was as the faster leaching kinetics at 50 °C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8 days and microscopic observations by SEM–EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20 mm-size sheets.

  16. Ground-state and excited-state structures of tungsten-benzylidyne complexes.

    PubMed

    Lovaasen, Benjamin M; Lockard, Jenny V; Cohen, Brian W; Yang, Shujiang; Zhang, Xiaoyi; Simpson, Cheslan K; Chen, Lin X; Hopkins, Michael D

    2012-05-21

    The molecular structure of the tungsten-benzylidyne complex trans-W(≡CPh)(dppe)(2)Cl (1; dppe = 1,2-bis(diphenylphosphino)ethane) in the singlet (d(xy))(2) ground state and luminescent triplet (d(xy))(1)(π*(WCPh))(1) excited state (1*) has been studied using X-ray transient absorption spectroscopy, X-ray crystallography, and density functional theory (DFT) calculations. Molecular-orbital considerations suggest that the W-C and W-P bond lengths should increase in the excited state because of the reduction of the formal W-C bond order and decrease in W→P π-backbonding, respectively, between 1 and 1*. This latter conclusion is supported by comparisons among the W-P bond lengths obtained from the X-ray crystal structures of 1, (d(xy))(1)-configured 1(+), and (d(xy))(2) [W(CPh)(dppe)(2)(NCMe)](+) (2(+)). X-ray transient absorption spectroscopic measurements of the excited-state structure of 1* reveal that the W-C bond length is the same (within experimental error) as that determined by X-ray crystallography for the ground state 1, while the average W-P/W-Cl distance increases by 0.04 Å in the excited state. The small excited-state elongation of the W-C bond relative to the M-E distortions found for M(≡E)L(n) (E = O, N) compounds with analogous (d(xy))(1)(π*(ME))(1) excited states is due to the π conjugation within the WCPh unit, which lessens the local W-C π-antibonding character of the π*(WCPh) lowest unoccupied molecular orbital (LUMO). These conclusions are supported by DFT calculations on 1 and 1*. The similar core bond distances of 1, 1(+), and 1* indicates that the inner-sphere reorganization energy associated with ground- and excited-state electron-transfer reactions is small.

  17. Ground-state and excited-state structures of tungsten-benzylidyne complexes

    SciTech Connect

    Lovaasen, B. M.; Lockard, J. V.; Cohen, B. W.; Yang, S.; Zhang, X.; Simpson, C. K.; Chen, L. X.; Hopkins, M. D.

    2012-01-01

    The molecular structure of the tungsten-benzylidyne complex trans-W({triple_bond}CPh)(dppe){sub 2}Cl (1; dppe = 1,2-bis(diphenylphosphino)ethane) in the singlet (d{sub xy}){sup 2} ground state and luminescent triplet (d{sub xy}){sup 1}({pi}*(WCPh)){sup 1} excited state (1*) has been studied using X-ray transient absorption spectroscopy, X-ray crystallography, and density functional theory (DFT) calculations. Molecular-orbital considerations suggest that the W-C and W-P bond lengths should increase in the excited state because of the reduction of the formal W-C bond order and decrease in W {yields} P {pi}-backbonding, respectively, between 1 and 1*. This latter conclusion is supported by comparisons among the W-P bond lengths obtained from the X-ray crystal structures of 1, (d{sub xy}){sup 1}-configured 1{sup +}, and (d{sub xy}){sup 2} [W(CPh)(dppe){sub 2}(NCMe)]{sup +} (2{sup +}). X-ray transient absorption spectroscopic measurements of the excited-state structure of 1* reveal that the W-C bond length is the same (within experimental error) as that determined by X-ray crystallography for the ground state 1, while the average W-P/W-Cl distance increases by 0.04 {angstrom} in the excited state. The small excited-state elongation of the W-C bond relative to the M-E distortions found for M({triple_bond}E)L{sub n} (E = O, N) compounds with analogous (d{sub xy}){sup 1}({pi}*(ME)){sup 1} excited states is due to the {pi} conjugation within the WCPh unit, which lessens the local W-C {pi}-antibonding character of the {pi}*(WCPh) lowest unoccupied molecular orbital (LUMO). These conclusions are supported by DFT calculations on 1 and 1*. The similar core bond distances of 1, 1{sup +}, and 1* indicates that the inner-sphere reorganization energy associated with ground- and excited-state electron-transfer reactions is small.

  18. Rovibrational constants of the ground state and v8 = 1 state of 13C2HD3 by high-resolution FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Ng, L. L.; Tan, T. L.

    2016-06-01

    The Fourier transform infrared (FTIR) spectrum of the c-type ν8 band of 13C2HD3 was recorded for the first time at a unapodized resolution of 0.0063 cm-1 in the wavenumber region of 830-1000 cm-1. Through the fitting of a total of 1057 assigned infrared transitions using Watson's A-reduced Hamiltonian in the Ir representation, rovibrational constants for the upper state (v8 = 1) up to five quartic centrifugal distortion terms were derived for the first time with a root-mean-square (rms) deviation of 0.00073 cm-1. The band center of ν8 of 13C2HD3 was found to be 913.011021(55) cm-1. Ground state rovibrational constants up to five quartic terms of 13C2HD3 were also determined from a fit of 453 ground state combination-differences from the present infrared measurements with an rms deviation of 0.00072 cm-1 for the first time. The uncertainty of the measured infrared lines was estimated to be ±0.0012 cm-1. From the ground state rotational constants, the inertial defect of 13C2HD3 was calculated to be 0.06973(16) uÅ2, showing the high planarity of the molecule.

  19. Ground beef consumption patterns in the United States, FoodNet, 2006 through 2007.

    PubMed

    Taylor, Ethel V; Holt, Kristin G; Mahon, Barbara E; Ayers, Tracy; Norton, Dawn; Gould, L Hannah

    2012-02-01

    Infection resulting from foodborne pathogens, including Escherichia coli O157:H7, is often associated with consumption of raw or undercooked ground beef. However, little is known about the frequency of ground beef consumption in the general population. The objective of this study was to describe patterns of self-reported ground beef and pink ground beef consumption using data from the 2006 through 2007 FoodNet Population Survey. From 1 July 2006 until 30 June 2007, residents of 10 FoodNet sites were contacted by telephone and asked about foods consumed within the previous week. The survey included questions regarding consumption of ground beef patties both inside and outside the home, the consumption of pink ground beef patties and other types of ground beef inside the home, and consumption of ground beef outside the home. Of 8,543 survey respondents, 75.3% reported consuming some type of ground beef in the home. Of respondents who ate ground beef patties in the home, 18.0% reported consuming pink ground beef. Consumption of ground beef was reported most frequently among men, persons with incomes from $40,000 to $75,000 per year, and persons with a high school or college education. Ground beef consumption was least often reported in adults ≥65 years of age. Men and persons with a graduate level education most commonly reported eating pink ground beef in the home. Reported consumption of ground beef and pink ground beef did not differ by season. Ground beef is a frequently consumed food item in the United States, and rates of consumption of pink ground beef have changed little since previous studies. The high rate of consumption of beef that has not been cooked sufficiently to kill pathogens makes pasteurization of ground beef an important consideration, especially for those individuals at high risk of complications from foodborne illnesses such as hemolytic uremic syndrome.

  20. Direct measurements of rotation-specific, state-to-state vibrational energy transfer in highly vibrationally excited acetylene

    NASA Astrophysics Data System (ADS)

    Tobiason, J. D.; Utz, A. L.; Crim, F. F.

    1994-07-01

    Vibrational overtone excitation followed by laser-induced fluorescence detection allows the direct measurement of rotationally resolved vibrational energy transfer rates in highly vibrationally excited acetylene molecules. We detect transfer from the initial, even rotational states Ji=0-22 of 3ν3 (ν˜0=9640 cm-1) to the nearly isoenergetic final state Jf=4 of ν1+ν2+ν3+2ν4, l=0 (ν˜0=9668 cm-1). For these pathways, we observe changes in energy of up to ‖ΔE‖=530 cm-1 (≊2.5 kT) and in angular momentum quantum number of up to ‖ΔJ‖=18 in a single collision, and we measure state-to-state rate constants of about 0.1 μs-1Torr-1 (160 collisions). Measurements under single collision conditions ensure that the vibrational relaxation is free of any rotational equilibration. By applying detailed balance and summing the resulting reverse rate constants, we obtain a total rate constant of 1.3 μs-1Torr-1 (13 collisions) for transfer from ν1+ν2+ν3+2ν4, l=0, Jf=4 to all final rotational states in 3ν3. The energy transfer rate between two specific rovibrational states decreases exponentially with increasing energy difference. The vibrational relaxation does not have a strong angular momentum dependence in general, but transfer from the initial rotational states 3ν3, J=16, and J=20 is anomalously fast. The Fermi resonance of 3ν3 and ν1+ν2+ν3+2ν4, l=0 appears to enhance collisional transfer between the pair by a factor of 10 or more over that for uncoupled levels, and the anomalously fast transfer from initial states 3ν3, J=16 and 20 is probably due to their relatively strong, rotation-specific intramolecular coupling with other nearby, unobserved vibrational states.

  1. High-K multi-quasiparticle states and rotational bands in {sub 103}{sup 255}Lr

    SciTech Connect

    Jeppesen, H. B.; Clark, R. M.; Gregorich, K. E.; Cromaz, M.; Deleplanque, M. A.; Dvorak, J.; Fallon, P.; Gros, S.; Lee, I. Y.; Macchiavelli, A. O.; Stavsetra, L.; Stephens, F. S.; Wiedeking, M.; Afanasjev, A. V.; Ali, M. N.; Dragojevic, I.; Ellison, P. A.; Garcia, M. A.; Gates, J. M.; Nelson, S. L.

    2009-09-15

    Two isomeric states have been identified in {sup 255}Lr. The decay of the isomers populates rotational structures. Comparison with macroscopic-microscopic calculations suggests that the lowest observed sequence is built upon the [624]9/2{sup +} Nilsson state. However, microscopic cranked relativistic Hartree-Bogoliubov (CRHB) calculations do not reproduce the moment of inertia within typical accuracy. This is a clear challenge to theories describing the heaviest elements.

  2. Calcific tendinitis of the rotator cuff: state of the art in diagnosis and treatment.

    PubMed

    Merolla, Giovanni; Singh, Sanjay; Paladini, Paolo; Porcellini, Giuseppe

    2016-03-01

    Calcific tendinitis is a painful shoulder disorder characterised by either single or multiple deposits in the rotator cuff tendon. Although the disease subsides spontaneously in most cases, a subpopulation of patients continue to complain of pain and shoulder dysfunction and the deposits do not show any signs of resolution. Although several treatment options have been proposed, clinical results are controversial and often the indication for a given therapy remains a matter of clinician choice. Herein, we report on the current state of the art in the pathogenesis, diagnosis and treatment of calcific tendinitis of the rotator cuff.

  3. Diffraction pattern by rotated conical tracks in solid state nuclear track detectors

    NASA Astrophysics Data System (ADS)

    Stevanovic, N.; Markovic, V. M.

    2016-06-01

    The method for determination of diffraction pattern for irregular 3D objects with application on rotated conical tracks in solid state nuclear track detector (SSNTD) wasdescribed in this paper. The model can be applied for different types of the diffraction (Fresnel, Fraunhofer) and arbitrary shapes of the obstacle. By applying the developed model on conical tracks it was fond that diffraction pattern strongly depends from radius, length and rotation angle of the conical tracks. These dependences were investigated in this paper and results can be applied for determination of inner tracks structure via diffraction pattern.

  4. Study on the ground states of a square-lattice polymer by using exhaustive enumeration

    NASA Astrophysics Data System (ADS)

    Lee, Jae Hwan; Lee, Julian; Kim, Seung-Yeon

    2016-11-01

    We exhaustively enumerate the ground-state conformations of polymers with attractive nearest-neighbor interactions on a square lattice. We find that when the ground-state number is considered as a function of the chain length, local minima appear at magic lengths. However, the ground-state entropy per monomer does not vanish in the thermodynamic limit when an extrapolation is performed with the magic-length data, implying that the number of ground-state conformations grows exponentially. We also study the entropy difference between the ground and the first-excited states. The entropy difference per monomer diverges in the thermodynamic limit, indicating that the zero-tail of the specific heat is modified in the thermodynamic limit.

  5. Simple solutions of fireball hydrodynamics for rotating and expanding triaxial ellipsoids and final state observables

    NASA Astrophysics Data System (ADS)

    Nagy, M. I.; Csörgő, T.

    2016-12-01

    We present a class of analytic solutions of nonrelativistic fireball hydrodynamics for a fairly general class of equation of state. The presented solution describes the expansion of a triaxial ellipsoid that rotates around one of its principal axes. We calculate the hadronic final state observables such as single-particle spectra, directed, elliptic, and third flows, as well as two-particle Bose-Einstein (also named HBT) correlations and corresponding radius parameters, utilizing simple analytic formulas. The final tilt angle of the fireball, an important observable quantity, is shown to be not independent of its exact definition: one gets different tilt angles from the geometrical anisotropies, from the single-particle spectra, and from HBT measurements. Taken together, the tilt angle in the momentum space and in the relative momentum or HBT variable may be sufficient for the determination of the magnitude of the rotation of the fireball. We argue that observing this rotation and its dependence on collision energy could characterize the softest point of the equation of state. Thus determining the rotation may be a powerful tool for the experimental search for the critical point in the phase diagram of strongly interacting matter.

  6. No-go theorem for ground state cooling given initial system-thermal bath factorization.

    PubMed

    Wu, Lian-Ao; Segal, Dvira; Brumer, Paul

    2013-01-01

    Ground-state cooling and pure state preparation of a small object that is embedded in a thermal environment is an important challenge and a highly desirable quantum technology. This paper proves, with two different methods, that a fundamental constraint on the cooling dynamic implies that it is impossible to cool, via a unitary system-bath quantum evolution, a system that is embedded in a thermal environment down to its ground state, if the initial state is a factorized product of system and bath states. The latter is a crucial but artificial assumption included in numerous tools that treat system-bath dynamics, such as master equation approaches and Kraus operator based methods. Adopting these approaches to address ground state and even approximate ground state cooling dynamics should therefore be done with caution, considering the fundamental theorem exposed in this work.

  7. Bose-Einstein condensates in rotating lattices.

    PubMed

    Bhat, Rajiv; Holland, M J; Carr, L D

    2006-02-17

    Strongly interacting bosons in a two-dimensional rotating square lattice are investigated via a modified Bose-Hubbard Hamiltonian. Such a system corresponds to a rotating lattice potential imprinted on a trapped Bose-Einstein condensate. Second-order quantum phase transitions between states of different symmetries are observed at discrete rotation rates. For the square lattice we study, there are four possible ground-state symmetries.

  8. Rotational spectrum of the AgS radical in the X2Πi state

    NASA Astrophysics Data System (ADS)

    Okabayashi, Toshiaki; Oya, Atsushi; Yamamoto, Takuya; Mizuguchi, Den-ichiro; Tanimoto, Mitsutoshi

    2016-11-01

    The rotational spectrum of the AgS radical in the X2Πi state was observed using a source-modulation microwave spectrometer. This radical was generated in a free-space cell by a DC glow discharge under Ar-diluted H2S. Silver atoms were supplied by sputtering from silver sheets placed on the inner surface of the stainless steel cathode. Rotational transitions from J = 7.5 - 6.5 to 39.5 - 38.5 were measured in the 58-310 GHz region. Rotational, centrifugal distortion, and several fine- and hyperfine-structure constants were determined by least-squares analysis. Other spectroscopic parameters such as the dissociation energy, vibrational wavenumber, and equilibrium bond length were also derived from the determined molecular constants. In addition, some electronic properties were estimated from the fine- and hyperfine-structure constants.

  9. Hindered and modulated rotational states and spectra of adsorbed diatomic molecules

    SciTech Connect

    Shih, Y.T.; Chuu, D.S.; Mei, W.N.

    1996-10-01

    Both vertical and horizontal adsorption configurations of a diatomic molecule were modeled as the rigid rotor with which the spatial motion was confined by a finite conical well. In addition to the polar hindering potential, a sinusoidal azimuthal modulation, which bears the local symmetry of the adsorption site, was incorporated. Eigenfunctions for different models were expressed analytically in terms of the hypergeometric functions, and eigenvalues were solved numerically. We found that the rotational energy levels exhibit oscillatory behavior when plotted as functions of the hindrance angle. This particular phenomenon was interpreted as the occurrence of resonance transmission of the rotor wave function at certain hindrance condition. We also found that the rotational levels were grouped into bands when the azimuthal modulation strength was increased. The solutions were used to calculate the rotational-state distribution of desorbed molecules, and agreement with the previous experiment was obtained. {copyright} {ital 1996 The American Physical Society.}

  10. A novel experiment using rotating magnetic fields to study the pumping spin states in molecular magnets

    NASA Astrophysics Data System (ADS)

    Hernandez-Minguez, Alberto; Macia, Ferran; Hernandez, Joan Manel; Carbonell, Carla; Amigó, Roger; Tejada, Javier

    2008-03-01

    We report here a new experimental technique to monitor spin population dynamics in molecular magnets. This deals with a huge rotating magnetic field initially applied along the easy magnetization direction, z--axis, that rotates with components parallel and perpendicular to the z axis. This technique allows us to probe spin relaxation on reasonably fast time scales detecting the inversion of the whole spin states. The population of spin levels depends on the frequency of the rotating magnetic field. This very new technique could help to carry out new experiments in a number of different fields, broadening substantially the scope of their use until now. A Hern'andez-M'inguez et al., Appl. Phys. Lett. 91, 202502 (2007)

  11. Semiclassical description of quantum rotator in terms of SU(2) coherent states

    NASA Astrophysics Data System (ADS)

    Gitman, D. M.; Petrusevich, D. A.; Shelepin, A. L.

    2013-10-01

    We introduce coordinates of the rigid body (rotator) using mutual positions between body-fixed and space-fixed reference frames. Wave functions that depend on such coordinates can be treated as scalar functions of the group SU(2). Irreducible representations of the group SU(2) × SU(2) in the space of such functions describe their possible transformations under independent rotations of the both reference frames. We construct sets of the corresponding group SU(2) × SU(2) Perelomov coherent states (CS) with a fixed angular momentum j of the rotator as special orbits of the latter group. Minimization of different uncertainty relations is discussed. The classical limit corresponds to the limit j → ∞. Considering Hamiltonians of rotators with different characteristics, we study the time evolution of the constructed CS. In some cases, the CS time evolution is completely or partially reduced to their parameter time evolution. If these parameters are chosen as Euler angles, then they obey the Euler equations in the classical limit. Quantum corrections to the motion of the quantum rotator can be found from exact equations on the CS parameters.

  12. ROTATION STATE OF COMET 103P/HARTLEY 2 FROM RADIO SPECTROSCOPY AT 1 mm

    SciTech Connect

    Drahus, Michal; Jewitt, David; Guilbert-Lepoutre, Aurelie; Waniak, Waclaw; Hoge, James; Lis, Dariusz C.; Yoshida, Hiroshige; Peng, Ruisheng; Sievers, Albrecht

    2011-06-10

    The nuclei of active comets emit molecules anisotropically from discrete vents. As the nucleus rotates, we expect to observe periodic variability in the molecular emission line profiles, which can be studied through millimeter/submillimeter spectroscopy. Using this technique we investigated the HCN atmosphere of comet 103P/Hartley 2, the target of NASA's EPOXI mission, which had an exceptionally favorable apparition in late 2010. We detected short-term evolution of the spectral line profile, which was stimulated by the nucleus rotation, and which provides evidence for rapid deceleration and excitation of the rotation state. The measured rate of change in the rotation period is +1.00 {+-} 0.15 minutes day{sup -1} and the period itself is 18.32 {+-} 0.03 hr, both applicable at the epoch of the EPOXI encounter. Surprisingly, the spin-down efficiency is lower by two orders of magnitude than the measurement in comet 9P/Tempel 1 and the best theoretical prediction. This secures rotational stability of the comet's nucleus during the next few returns, although we anticipate a catastrophic disruption from spin-up as its ultimate fate.

  13. Ground-state modulation-enhancement by two-state lasing in quantum-dot laser devices

    SciTech Connect

    Röhm, André; Lingnau, Benjamin; Lüdge, Kathy

    2015-05-11

    We predict a significant increase of the 3 dB-cutoff-frequency on the ground-state lasing wavelength for two-state-lasing quantum-dot lasers using a microscopically motivated multi-level rate-equation model. After the onset of the second lasing line, the excited state acts as a high-pass filter, improving the ground-state response to faster modulation frequencies. We present both numerically simulated small-signal and large-signal modulation results and compare the performance of single and two-state lasing devices. Furthermore, we give dynamical arguments for the advantages of two-state lasing on data-transmission capabilities.

  14. Pressure dependence of the magnetic ground states in MnP

    SciTech Connect

    Matsuda, Masaaki; Ye, Feng; Dissanayake, Sachith E.; Cheng, J. -G.; Chi, Songxue; Ma, Jie; Zhou, H. D.; Yan, Jia -Qiang; Kasamatsu, S.; Sugino, O.; Kato, T.; Matsubayashi, Kazuyuki; Okada, T.; Uwatoko, Yoshiya

    2016-03-17

    MnP, a superconductor under pressure, exhibits a ferromagnetic order below TC~290 K followed by a helical order with the spins lying in the ab plane and the helical rotation propagating along the c axis below Ts~50 K at ambient pressure. We performed single-crystal neutron diffraction experiments to determine the magnetic ground states under pressure. Both TC and Ts are gradually suppressed with increasing pressure and the helical order disappears at ~1.2 GPa. At intermediate pressures of 1.8 and 2.0 GPa, the ferromagnetic order first develops and changes to a conical or two-phase (ferromagnetic and helical) structure with the propagation along the b axis below a characteristic temperature. At 3.8 GPa, a helical magnetic order appears below 208 K, which hosts the spins in the ac plane and the propagation along the b axis. The period of this b axis modulation is shorter than that at 1.8 GPa. Here, our results indicate that the magnetic phase in the vicinity of the superconducting phase may have a helical magnetic correlation along the b axis.

  15. Pressure dependence of the magnetic ground states in MnP

    DOE PAGES

    Matsuda, Masaaki; Ye, Feng; Dissanayake, Sachith E.; ...

    2016-03-17

    MnP, a superconductor under pressure, exhibits a ferromagnetic order below TC~290 K followed by a helical order with the spins lying in the ab plane and the helical rotation propagating along the c axis below Ts~50 K at ambient pressure. We performed single-crystal neutron diffraction experiments to determine the magnetic ground states under pressure. Both TC and Ts are gradually suppressed with increasing pressure and the helical order disappears at ~1.2 GPa. At intermediate pressures of 1.8 and 2.0 GPa, the ferromagnetic order first develops and changes to a conical or two-phase (ferromagnetic and helical) structure with the propagation alongmore » the b axis below a characteristic temperature. At 3.8 GPa, a helical magnetic order appears below 208 K, which hosts the spins in the ac plane and the propagation along the b axis. The period of this b axis modulation is shorter than that at 1.8 GPa. Here, our results indicate that the magnetic phase in the vicinity of the superconducting phase may have a helical magnetic correlation along the b axis.« less

  16. Rotationally resolved state-to-state photoionization and photoelectron study of titanium carbide and its cation (TiC/TiC⁺).

    PubMed

    Luo, Zhihong; Huang, Huang; Chang, Yih-Chung; Zhang, Zheng; Yin, Qing-Zhu; Ng, C Y

    2014-10-14

    Titanium carbide and its cation (TiC/TiC(+)) have been investigated by the two-color visible (VIS)-ultraviolet (UV) resonance-enhanced photoionization and pulsed field ionization-photoelectron (PFI-PE) methods. Two visible excitation bands for neutral TiC are observed at 16,446 and 16,930 cm(-1). Based on rotational analyses, these bands are assigned as the respective TiC((3)Π1) ← TiC(X(3)Σ(+)) and TiC((3)Σ(+)) ← TiC(X(3)Σ(+)) transition bands. This assignment supports that the electronic configuration and term symmetry for the neutral TiC ground state are …7σ(2)8σ(1)9σ(1)3π(4) (X(3)Σ(+)). The rotational constant and the corresponding bond distance of TiC(X(3)Σ(+); v″ = 0) are determined to be B0″ = 0.6112(10) cm(-1) and r0″ = 1.695(2) Å, respectively. The rotational analyses of the VIS-UV-PFI-PE spectra for the TiC(+)(X; v(+) = 0 and 1) vibrational bands show that the electronic configuration and term symmetry for the ionic TiC(+) ground state are …7σ(2)8σ(1)3π(4) (X(2)Σ(+)) with the v(+) = 0 → 1 vibrational spacing of 870.0(8) cm(-1) and the rotational constants of B(e)(+) = 0.6322(28) cm(-1), and α(e)(+) = 0.0085(28) cm(-1). The latter rotational constants yield the equilibrium bond distance of r(e)(+) = 1.667(4) Å for TiC(+)(X(2)Σ(+)). The cleanly rotationally resolved VIS-UV-PFI-PE spectra have also provided a highly precise value of 53 200.2(8) cm(-1) [6.5960(1) eV] for the adiabatic ionization energy (IE) of TiC. This IE(TiC) value along with the known IE(Ti) has made possible the determination of the difference between the 0 K bond dissociation energy (D0) of TiC(+)(X(2)Σ(+)) and that of TiC(X(3)Σ(+)) to be D0(Ti(+)-C) - D0(Ti-C) = 0.2322(2) eV. Similar to previous experimental observations, the present state-to-state PFI-PE study of the photoionization transitions, TiC(+)(X(2)Σ(+); v(+) = 0 and 1, N(+)) ← TiC((3)Π1; v', J'), reveals a strong decreasing trend for the photoionization cross section as |ΔN(+)| = |N

  17. Rotationally resolved state-to-state photoionization and photoelectron study of titanium carbide and its cation (TiC/TiC+)

    NASA Astrophysics Data System (ADS)

    Luo, Zhihong; Huang, Huang; Chang, Yih-Chung; Zhang, Zheng; Yin, Qing-Zhu; Ng, C. Y.

    2014-10-01

    Titanium carbide and its cation (TiC/TiC+) have been investigated by the two-color visible (VIS)-ultraviolet (UV) resonance-enhanced photoionization and pulsed field ionization-photoelectron (PFI-PE) methods. Two visible excitation bands for neutral TiC are observed at 16 446 and 16 930 cm-1. Based on rotational analyses, these bands are assigned as the respective TiC(3Π1) ← TiC(X3Σ+) and TiC(3Σ+) ← TiC(X3Σ+) transition bands. This assignment supports that the electronic configuration and term symmetry for the neutral TiC ground state are …7σ28σ19σ13π4 (X3Σ+). The rotational constant and the corresponding bond distance of TiC(X3Σ+; v″ = 0) are determined to be B0″ = 0.6112(10) cm-1 and r0″ = 1.695(2) Å, respectively. The rotational analyses of the VIS-UV-PFI-PE spectra for the TiC+(X; v+ = 0 and 1) vibrational bands show that the electronic configuration and term symmetry for the ionic TiC+ ground state are …7σ28σ13π4 (X2Σ+) with the v+ = 0 → 1 vibrational spacing of 870.0(8) cm-1 and the rotational constants of Be+ = 0.6322(28) cm-1, and αe+ = 0.0085(28) cm-1. The latter rotational constants yield the equilibrium bond distance of re+ = 1.667(4) Å for TiC+(X2Σ+). The cleanly rotationally resolved VIS-UV-PFI-PE spectra have also provided a highly precise value of 53 200.2(8) cm-1 [6.5960(1) eV] for the adiabatic ionization energy (IE) of TiC. This IE(TiC) value along with the known IE(Ti) has made possible the determination of the difference between the 0 K bond dissociation energy (D0) of TiC+(X2Σ+) and that of TiC(X3Σ+) to be D0(Ti+-C) - D0(Ti-C) = 0.2322(2) eV. Similar to previous experimental observations, the present state-to-state PFI-PE study of the photoionization transitions, TiC+(X2Σ+; v+ = 0 and 1, N+) ← TiC(3Π1; v', J'), reveals a strong decreasing trend for the photoionization cross section as |ΔN+| = |N+ - J'| is increased. The maximum |ΔN+| change of 7 observed here is also consistent with the previous

  18. Sub-millimeter wave spectroscopy of the C 3H radical: Ro-vibrational transitions from ground to the lowest bending state

    NASA Astrophysics Data System (ADS)

    Caris, M.; Giesen, T. F.; Duan, C.; Müller, H. S. P.; Schlemmer, S.; Yamada, K. M. T.

    2009-02-01

    Linear C 3H in its (X 2Π) electronic ground state possesses strong Renner-Teller coupling in the two lowest bending modes, ν4 and ν5. The 2Σμ level of the v4 = 1 bending mode is shifted towards lower energies and is supposed to lie only 20.3 cm -1 above the ground state [S. Yamamoto, S. Saito, H. Suzuki, S. Deguchi, N. Kaifu, S. Ishikawa, M. Ohishi, Astrophys. J. 348 (1990) 363]. In the present study, first measurements of ro-vibrational transitions from the 2Π3/2 ground state to the 2Σμ lowest vibrational state were performed using a Terahertz spectrometer equipped with a supersonic jet nozzle. Rotational levels of the 2Π3/2 and v4 = 1( 2Σμ) state are close in energy and a crossing of the rotational energy ladders occurs between J = 24.5 and 25.5. A strong vibronic coupling leads to a significant intensity enhancement of 2Π3/2 - 2Σμ ro-vibrational transitions. The search for ro-vibrational transitions was facilitated by measurements on pure rotational transitions in the 2Π1/2, 2Π3/2 and v4 = 1( 2Σμ) states, substantially extending the former data set published by Yamamoto et al. Data analysis yields an accurate value for the v4 = 1( 2Σμ) energy level which has been found to lie 609.9771(42) GHz or 20.34664(14) cm -1 above the 2Π ground state. Furthermore, the value of the vibronic coupling constant β has been improved significantly and determined as 1231.77(51) MHz. The new set of spectroscopic parameters obtained in the present study permits very reliable frequency predictions into the Terahertz region.

  19. The Ground State of Monolayer Graphene in a Strong Magnetic Field

    PubMed Central

    Wu, Lian-Ao; Guidry, Mike

    2016-01-01

    Experiments indicate that the ground state of graphene in a strong magnetic field exhibits spontaneous breaking of SU(4) symmetry. However, the nature of the corresponding emergent state is unclear because existing theoretical methods approximate the broken-symmetry solutions, yielding nearly-degenerate candidate ground states having different emergent orders. Resolving this ambiguity in the nature of the strong-field ground state is highly desirable, given the importance of graphene for both fundamental physics and technical applications. We have discovered a new SO(8) symmetry that recovers standard graphene SU(4) quantum Hall physics, but predicts two new broken-SU(4) phases and new properties for potential ground states. Our solutions are analytical; thus we capture the essential physics of spontaneously-broken SU(4) states in a powerful yet solvable model useful both in correlating existing data and in suggesting new experiments. PMID:26927477

  20. Development of three-dimensional state-space wake theory and application in dynamic ground effect

    NASA Astrophysics Data System (ADS)

    Yu, Ke

    In topics of rotorcraft wake analysis, state-space wake theory has a recognized reputation for advantages in real-time simulation, preliminary design and eigenvalue analysis. Developments in the past decades greatly improved range of validity and accuracy of the state-space modeling approach. This work focuses on further improvement of the state-space wake theory and applications in representing dynamic ground effect. Extended state-space model is developed to represent non-zero mass flux on rotor disk. Its instant practical application, representing ground effect with a mass source ground rotor, is evaluated in both steady and dynamic aspects. Investigations of partial ground effect simulation by state-space model are carried out in different rotor configurations. Additional work is done in improving simulation efficiency of practical application of state-space modeling.

  1. Short rotation woody crops: Using agroforestry technology for energy in the United States

    SciTech Connect

    Wright, L L; Ranney, J W

    1991-01-01

    Agroforestry in the United States is being primarily defined as the process of using trees in agricultural systems for conservation purposes and multiple products. The type of agroforestry most commonly practiced in many parts of the world, that is the planting of tree crops in combination with food crops or pasture, is the type least commonly practiced in the United States. One type of agroforestry technique, which is beginning now and anticipated to expand to several million acres in the United States, is the planting of short-rotation woody crops (SRWCs) primarily to provide fiber and fuel. Research on SRWC's and environmental concerns are described.

  2. Short rotation woody crops: Using agroforestry technology for energy in the United States

    SciTech Connect

    Wright, L.L.; Ranney, J.W.

    1991-12-31

    Agroforestry in the United States is being primarily defined as the process of using trees in agricultural systems for conservation purposes and multiple products. The type of agroforestry most commonly practiced in many parts of the world, that is the planting of tree crops in combination with food crops or pasture, is the type least commonly practiced in the United States. One type of agroforestry technique, which is beginning now and anticipated to expand to several million acres in the United States, is the planting of short-rotation woody crops (SRWCs) primarily to provide fiber and fuel. Research on SRWC`s and environmental concerns are described.

  3. Exact ground states of large two-dimensional planar Ising spin glasses

    NASA Astrophysics Data System (ADS)

    Pardella, G.; Liers, F.

    2008-11-01

    Studying spin-glass physics through analyzing their ground-state properties has a long history. Although there exist polynomial-time algorithms for the two-dimensional planar case, where the problem of finding ground states is transformed to a minimum-weight perfect matching problem, the reachable system sizes have been limited both by the needed CPU time and by memory requirements. In this work, we present an algorithm for the calculation of exact ground states for two-dimensional Ising spin glasses with free boundary conditions in at least one direction. The algorithmic foundations of the method date back to the work of Kasteleyn from the 1960s for computing the complete partition function of the Ising model. Using Kasteleyn cities, we calculate exact ground states for huge two-dimensional planar Ising spin-glass lattices (up to 30002 spins) within reasonable time. According to our knowledge, these are the largest sizes currently available. Kasteleyn cities were recently also used by Thomas and Middleton in the context of extended ground states on the torus. Moreover, they show that the method can also be used for computing ground states of planar graphs. Furthermore, we point out that the correctness of heuristically computed ground states can easily be verified. Finally, we evaluate the solution quality of heuristic variants of the L. Bieche approach.

  4. Influence of Lattice Vibration on the Ground State of Magnetopolaron in a Parabolic Quantum Dot

    NASA Astrophysics Data System (ADS)

    Eerdunchaolu; Xin, Wei; Zhao, Yuwei

    Influence of the lattice vibration on the properties of the magnetopolaron in the parabolic quantum dots (QDs) is studied by using the Huybrechts' linear combination operator and Lee-Low-Pines (LLP) transformation methods. The expressions for the vibration frequency and the ground-state energy of the magnetopolaron as functions of the confinement strength of the QDs, the magnetic field and temperature are derived under the strong and weak coupling, respectively. The results of the numerical calculations show that the changes of the vibration frequency and ground-state energy of the magnetopolaron with the confinement strength of the QDs, the magnetic field and temperature are different under different couplings. The vibration frequency and the ground-state energy of the weak-coupling magnetopolaron and the vibration frequency of the strong-coupling magnetopolaron will increase with increase of the confinement strength of the QDs and cyclotron frequency, the vibration frequency and ground-state energy of the strong-coupling magnetopolaron. However, the ground-state energy of the weak-coupling magnetopolaron will decrease with increase of the temperature. The dependence of the ground-state energy of the strong-coupling magnetopolaron on the confinement strength of the QDs and cyclotron frequency is strongly influenced by the temperature. The remarkable influence of the temperature on the ground-state energy of the magnetopolaron arises when the temperature is relatively higher.

  5. Exact spin-cluster ground states in a mixed diamond chain

    NASA Astrophysics Data System (ADS)

    Takano, Ken'Ichi; Suzuki, Hidenori; Hida, Kazuo

    2009-09-01

    The mixed diamond chain is a frustrated Heisenberg chain composed of successive diamond-shaped units with two kinds of spins of magnitudes S and S/2 ( S : integer). Ratio λ of two exchange parameters controls the strength of frustration. With varying λ , the Haldane state and several spin-cluster states appear as the ground state. A spin-cluster state is a tensor product of exact local eigenstates of cluster spins. We prove that a spin-cluster state is the ground state in a finite interval of λ . For S=1 , we numerically determine the total phase diagram consisting of five phases.

  6. Protolytic dissociation of cyanophenols in ground and excited states in alcohol and water solutions

    NASA Astrophysics Data System (ADS)

    Szczepanik, Beata; Styrcz, Stanisław

    2011-08-01

    The effect of cyano substituents on acidity in ground and excited states of mono- and dicyanophenols was investigated. The equilibrium dissociation constants of 3,4-dicyanophenol in ground and lowest excited states in water solution and the change of these constants in the excited state during the transfer to the ground state for o-, m-, p-cyanophenol and 3,4-dicyanophenol in alcohol and water solutions were determined. It was shown that the cyano substitution increases the acidity of ortho-, meta- and dicyano-derivative in ground state in comparison to the phenol, which makes the anions of these derivatives appear in solutions from methanol to 1-butanol. In the excited state the acidity of investigated compounds changes significantly in comparison to the ground state. 3,4-Dicyanophenol is the strongest acid in the lowest excited singlet state, while p-cyanophenol is the weakest one in both alcohol and water solutions. The distribution of the electronic charge and dipole moments of all investigated cyanophenols in ground and excited states were determined on the basis of ab initio calculations using the GAMESS program.

  7. Matrix elements for the ground-state to ground-state 2{nu}{beta}{sup -}{beta}{sup -} decay of Te isotopes in a hybrid model

    SciTech Connect

    Bes, D. R.; Civitarese, O.

    2010-01-15

    Theoretical matrix elements, for the ground-state to ground-state two-neutrino double-{beta}-decay mode (2{nu}{beta}{sup -}{beta}{sup -}gs->gs) of {sup 128,130}Te isotopes, are calculated within a formalism that describes interactions between neutrons in a superfluid phase and protons in a normal phase. The elementary degrees of freedom of the model are proton-pair modes and pairs of protons and quasineutrons. The calculation is basically a parameter-free one, because all relevant parameters are fixed from the phenomenology. A comparison with the available experimental data is presented.

  8. Ground state properties of superheavy nuclei with Z=117 and Z=119

    SciTech Connect

    Ren Zhongzhou; Chen Dinghan; Xu Chang

    2006-11-02

    We review the current studies on the ground-state properties of superheavy nuclei. It is shown that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. This can lead to the existence of isomers in superheavy region and it plays an important role for the stability of superheavy nuclei. Some new results on Z=117 and Z=119 isotopes are presented. The agreement between theoretical results and experimental data clearly demonstrates the validity of theoretical models for the ground-state properties of superheavy nuclei.

  9. Atomic Charges and the Electrostatic Potential Are Ill-Defined in Degenerate Ground States.

    PubMed

    Bultinck, Patrick; Cardenas, Carlos; Fuentealba, Patricio; Johnson, Paul A; Ayers, Paul W

    2013-11-12

    A system in a spatially degenerate ground state responds in a qualitatively different way to positive and negative point charges. This means that the molecular electrostatic potential is ill-defined for degenerate ground states due to the ill-defined nature of the electron density. It also means that it is impossible, in practice, to define fixed atomic charges for molecular mechanics simulations of molecules with (quasi-)degenerate ground states. Atomic-polarizability-based models and electronegativity-equalization-type models for molecular polarization also fail to capture this effect. We demonstrate the ambiguity in the electrostatic potential using several molecules of different degree of degeneracy, quasi-degeneracy, and symmetry.

  10. Degenerated ground-states in a spin chain with pair interactions: a characterization by symbolic dynamics

    NASA Astrophysics Data System (ADS)

    Corona, L. A.; Salgado-García, R.

    2016-12-01

    In this paper we study a class of one-dimensional spin chain having a highly degenerated set of ground-state configurations. The model consists of spin chain having infinite-range pair interactions with a given structure. We show that the set of ground-state configurations of such a model can be fully characterized by means of symbolic dynamics. Particularly we found that the set ground-state configurations define what in symbolic dynamics is called sofic shift space. Finally we prove that this system has a non-vanishing residual entropy (the topological entropy of the shift space), which can be exactly calculated.

  11. Off-diagonal long-range order (ODLRO) and ground state properties of liquid helium

    SciTech Connect

    Rodriguez-Gomez, J.R.

    1983-01-01

    An independent calculation of the condensate fraction and the ground state energy of liquid helium is given. The Froehlich ansatz for the second reduced density matrix in conjunction with the ODLORO hypothesis for liquid helium below the critical temperature is used. Froehlich's ansatz is shown to be consistent with numerical calculations of the ground state properties of liquid helium. The ground state energy was -5.10/sup 0/K, close to the experimental value. The condensate fraction turned out to be about 10% which is within the margin of error of recent neutron scattering experiments and agrees with other theoretical calculations.

  12. A molecular-field approximation for quantum crystals. Ph.D. Thesis; [considering ground state properties

    NASA Technical Reports Server (NTRS)

    Danilowicz, R.

    1973-01-01

    Ground-state properties of quantum crystals have received considerable attention from both theorists and experimentalists. The theoretical results have varied widely with the Monte Carlo calculations being the most successful. The molecular field approximation yields ground-state properties which agree closely with the Monte Carlo results. This approach evaluates the dynamical behavior of each pair of molecules in the molecular field of the other N-2 molecules. In addition to predicting ground-state properties that agree well with experiment, this approach yields data on the relative importance of interactions of different nearest neighbor pairs.

  13. Ground-state energies of the nonlinear sigma model and the Heisenberg spin chains

    NASA Technical Reports Server (NTRS)

    Zhang, Shoucheng; Schulz, H. J.; Ziman, Timothy

    1989-01-01

    A theorem on the O(3) nonlinear sigma model with the topological theta term is proved, which states that the ground-state energy at theta = pi is always higher than the ground-state energy at theta = 0, for the same value of the coupling constant g. Provided that the nonlinear sigma model gives the correct description for the Heisenberg spin chains in the large-s limit, this theorem makes a definite prediction relating the ground-state energies of the half-integer and the integer spin chains. The ground-state energies obtained from the exact Bethe ansatz solution for the spin-1/2 chain and the numerical diagonalization on the spin-1, spin-3/2, and spin-2 chains support this prediction.

  14. Molecular spectroscopy for producing ultracold ground-state NaRb molecules

    NASA Astrophysics Data System (ADS)

    Wang, Dajun; Guo, Mingyang; Zhu, Bing; Lu, Bo; Ye, Xin; Wang, Fudong; Vexiau, Romain; Bouloufa-Maafa, Nadia; Quéméner, Goulven; Dulieu, Olivier

    2016-05-01

    Recently, we have successfully created an ultracold sample of absolute ground-state NaRb molecules by two-photon Raman transfer of weakly bound Feshbach molecules. Here we will present the detailed spectroscopic investigations on both the excited and the rovibrational ground states for finding the two-photon path. For the excited state, we focus on the A1Σ+ /b3 Π singlet and triplet admixture. We discovered an anomalously strong coupling between the Ω =0+ and 0- components which renders efficient population transfer possible. In the ground state, the pure nuclear hyperfine levels have been clearly resolved, which allows us to create molecules in the absolute ground state directly with Raman transfer. This work is jointly supported by Agence Nationale de la Recherche (#ANR-13- IS04-0004-01) and Hong Kong Research Grant Council (#A-CUHK403/13) through the COPOMOL project.

  15. Theoretical Study of Tautomerization Reactions for the Ground and First Excited Electronic States of Adenine

    NASA Technical Reports Server (NTRS)

    Salter, Latasha M.; Chaban, Galina M.; Kwak, Dochan (Technical Monitor)

    2002-01-01

    Geometrical structures and energetic properties for different tautomers of adenine are calculated in this study, using multi-configurational wave functions. Both the ground and the lowest singlet excited state potential energy surfaces are studied. Four tautomeric forms are considered, and their energetic order is found to be different on the ground and the excited state potential energy surfaces. Minimum energy reaction paths are obtained for hydrogen atom transfer (tautomerization) reactions in the ground and the lowest excited electronic states. It is found that the barrier heights and the shapes of the reaction paths are different for the ground and the excited electronic states, suggesting that the probability of such tautomerization reaction is higher on the excited state potential energy surface. This tautomerization process should become possible in the presence of water or other polar solvent molecules and should play an important role in the photochemistry of adenine.

  16. Global Properties of Rotating Neutron Stars with QCD Equations of State

    NASA Astrophysics Data System (ADS)

    Gorda, Tyler

    2016-11-01

    We numerically investigate global properties of rotating neutron stars (NSs) using the allowed band of QCD equations of state derived by Kurkela et al. This band is constrained by chiral effective theory at low densities and perturbative QCD at high densities, and is thus, in essence, a controlled constraint from first-principles physics. Previously, this band of equations of state was used to investigate non-rotating NSs only; in this work, we extend these results to any rotation frequency below the mass-shedding limit. We investigate mass–radius curves, allowed mass–frequency regions, radius–frequency curves for a typical 1.4{M}ȯ star, and the values of the moment of inertia of the double pulsar PSR J0737-3039A, a pulsar for which the moment of inertia may be constrained observationally in a few years. We present limits on observational data coming from these constraints, and identify values of observationally relevant parameters that would further constrain the allowed region for the QCD equation of state. We also discuss how much this region would be constrained by a measurement of the moment of inertia of the double pulsar PSR J0737-3039A.

  17. GroundBIRD: Observing Cosmic Microwave Polarization at Large Angular Scale with Kinetic Inductance Detectors and High-Speed Rotating Telescope

    NASA Astrophysics Data System (ADS)

    Oguri, S.; Choi, J.; Damayanthi, T.; Hattori, M.; Hazumi, M.; Ishitsuka, H.; Karatsu, K.; Mima, S.; Minowa, M.; Nagasaki, T.; Otani, C.; Sekimoto, Y.; Tajima, O.; Tomita, N.; Yoshida, M.; Won, E.

    2016-08-01

    Cosmic microwave background (CMB) is an important source of information about the origin of our universe. In particular, odd-parity large angular scale patterns in the CMB polarization, the primordial B-modes, are strong evidence for an inflationary universe, related to the accelerating expansion of the metric. We are developing a unique telescope, GroundBIRD, to take CMB polarization measurements. The telescope combines novel techniques: high-speed rotation scanning, cold optics, and microwave kinetic inductance detectors (MKIDs). We evaluated the response of MKIDs on the rotation stage. Method of shielding from the geo-magnetic field is established. We have also developed a receiver cryostat. We are able to maintain a sufficient cold status for observations on the optical configuration. We plan to start commissioning the system by observing CMB in Japan in 2015-2016. We will then deploy GroundBIRD in the Canary Islands for further scientific observations.

  18. Symmetry Beyond Perturbation Theory: Floppy Molecules and Rotation-Vibration States

    NASA Astrophysics Data System (ADS)

    Schmiedt, Hanno; Schlemmer, Stephan; Jensen, Per

    2015-06-01

    In the customary approach to the theoretical description of the nuclear motion in molecules, the molecule is seen as a near-static structure rotating in space. Vibrational motion causing small structural deformations induces a perturbative treatment of the rotation-vibration interaction, which fails in fluxional molecules, where all vibrational motions are large compared to the linear extension of the molecule. An example is protonated methane (CH_5^+). For this molecule, customary theory fails to simulate reliably even the low-energy spectrum. Within the traditional view of rotation and vibration being near-separable, rotational and vibrational wavefunctions can be symmetry classified separately in the molecular symmetry (MS) group. In the present contribution we discuss a fundamental group theoretical approach to the problem of determining the symmetries of molecular rotation-vibration states. We will show that all MS groups discussed so far are subgroups of the special orthogonal group in three dimensions SO(3) This leads to a group theoretical foundation of the technique of equivalent rotations. The MS group of protonated methane (G240) represents, to the best of our knowledge, the first example of an MS group which is not a subgroup of SO(3) (nor of O(3) nor of SU(2)). Because of this, a separate symmetry classification of vibrational and rotational wavefunctions becomes impossible in this MS group, consistent with the fact that a decoupling of vibrational and rotational motion is impossible. We want to discuss the consequences of this. In conclusion, we show that the prototypical floppy molecule CH_5^+ represents a new class of molecules, where usual group theoretical methods for determining selection rules and spectral assignments fail so that new methods have to be developed. P. Kumar and D. Marx, Physical Chemistry Chemical Physics 8, 573 (2006) Z. Jin, B. J. Braams, and J. M. Bowman, The Journal of Physical Chemistry A 110, 1569 (2006) A. S. Petit, J. E

  19. Symmetry of extremely floppy molecules: Molecular states beyond rotation-vibration separation

    NASA Astrophysics Data System (ADS)

    Schmiedt, Hanno; Schlemmer, Stephan; Jensen, Per

    2015-10-01

    Traditionally, molecules are theoretically described as near-static structures rotating in space. Vibrational motion causing small structural deformations induces a perturbative treatment of the rotation-vibration interaction, which fails in highly fluxional molecules, where all vibrational motions have amplitudes comparable in size to the linear dimensions of the molecule. An example is protonated methane (CH 5+ ) [P. Kumar and D. Marx, Phys. Chem. Chem. Phys. 8, 573 (2006); Z. Jin et al., J. Phys. Chem. A 110, 1569 (2006); and A. S. Petit et al., J. Phys. Chem. A 118, 7206 (2014)]. For these molecules, customary theory fails to simulate reliably even the low-energy spectrum [T. Oka, Science 347, 1313-1314 (2015) and O. Asvany et al., Science 347, 1346-1349 (2015)]. Within the traditional view of rotation and vibration being near-separable, rotational and vibrational wavefunctions can be symmetry classified separately in the molecular symmetry (MS) group [P. Bunker and P. Jensen, Molecular Symmetry and Spectroscopy, NRC Monograph Publishing Program (NRC Research Press, 2006)]. In this article, we discuss a fundamental group theoretical approach to the problem of determining the symmetries of molecular rotation-vibration states. We will show that all MS groups discussed so far are isomorphic to subgroups of the special orthogonal group in three dimensions SO(3). This leads to a group theoretical foundation of the technique of equivalent rotations [H. Longuet-Higgins, Mol. Phys. 6, 445 (1963)]. The group G240 (the MS group of protonated methane) represents, to the best of our knowledge, the first example of a MS group which is not isomorphic to a subgroup of SO(3) (nor of O(3) or of SU(2)). Because of this, a separate symmetry classification of vibrational and rotational wavefunctions becomes impossible in this MS group, consistent with the fact that a decoupling of vibrational and rotational motion is impossible. We discuss here the consequences of this. In

  20. Ground and excited state dipole moments of coumarin 337 laser dye

    NASA Astrophysics Data System (ADS)

    Raikar, U. S.; Tangod, V. B.; Mannopantar, S. R.; Mastiholi, B. M.

    2010-11-01

    This paper reports that the effects of spectral properties of coumarin 337 laser dye have been investigated in different solvents considering solvent parameters like dielectric constant ( є) and refractive index ( n) of different solvent polarities. The ground state ( μg) and excited state ( μe) dipole moments are calculated using Lippert's, Bakhshiev's, and Kawski-Chamma-Viallet's equations. In all these three equations the variation of Stokes shift was used to calculate the excited state ( μe) dipole moment. It is observed that the Bakhshiev method is comparatively better than the other two methods for ground state and excited state dipole moment calculations. The angle between the excited state and ground state dipole moments is also calculated.

  1. Explaining the Temperature Dependence of Spirilloxanthin’s S* Signal by an Inhomogeneous Ground State Model

    PubMed Central

    2013-01-01

    We investigate the nature of the S* excited state in carotenoids by performing a series of pump–probe experiments with sub-20 fs time resolution on spirilloxanthin in a polymethyl-methacrylate matrix varying the sample temperature. Following photoexcitation, we observe sub-200 fs internal conversion of the bright S2 state into the lower-lying S1 and S* states, which in turn relax to the ground state on a picosecond time scale. Upon cooling down the sample to 77 K, we observe a systematic decrease of the S*/S1 ratio. This result can be explained by assuming two thermally populated ground state isomers. The higher lying one generates the S* state, which can then be effectively frozen out by cooling. These findings are supported by quantum chemical modeling and provide strong evidence for the existence and importance of ground state isomers in the photophysics of carotenoids. PMID:23577754

  2. Estimation of ground and excited state dipole moments of some laser dyes

    NASA Astrophysics Data System (ADS)

    Biradar, D. S.; Siddlingeshwar, B.; Hanagodimath, S. M.

    2008-03-01

    The ground state ( μg) and the excited state ( μe) dipole moments of three laser dyes namely 2, 5-diphenyl-1, 3, 4- oxadiazole (PPD), 2, 2″-dimethyl-p-terphenyl (DMT) and 1, 3-diphenyl benzene (MT) were studied at room temperature in various solvents. The ground state dipole moments ( μg) of all the three laser dyes were determined experimentally by Guggenheim method. The excited state dipole moments ( μe) were estimated from Lippert's, Bakshiev's and Chamma Viallet's equations by using the variation of the Stokes shift with the solvent dielectric constant and refractive index. Ground and excited state dipole moments were evaluated by means of solvatochromic shift method and also the excited state dipole moments are determined in combination with ground state dipole moments. It was observed that dipole moment values of excited states ( μe) were higher than corresponding ground state values ( μg), indicating a substantial redistribution of the π-electron densities in a more polar excited state for all the dyes investigated.

  3. Optical pumping of metastable NH radicals into the paramagnetic ground state

    SciTech Connect

    Meerakker, Sebastiaan Y.T. van de; Mosk, Allard P.; Jongma, Rienk T.; Sartakov, Boris G.; Meijer, Gerard

    2003-09-01

    We here report on the optical pumping of both {sup 14}NH and {sup 15}NH radicals from the metastable a {sup 1}{delta} state into the X {sup 3}{sigma}{sup -} ground state in a molecular beam experiment. By inducing the hitherto unobserved spin-forbidden A {sup 3}{pi} <- a {sup 1}{delta} transition, followed by spontaneous emission to the X {sup 3}{sigma}{sup -} state, a unidirectional pathway for population transfer from the metastable state into the electronic ground state is obtained. The optical pumping scheme demonstrated here opens up the possibility to accumulate NH radicals in a magnetic or optical trap.

  4. Switching between ground and excited states by optical feedback in a quantum dot laser diode

    SciTech Connect

    Virte, Martin; Breuer, Stefan; Sciamanna, Marc; Panajotov, Krassimir

    2014-09-22

    We demonstrate switching between ground state and excited state emission in a quantum-dot laser subject to optical feedback. Even though the solitary laser emits only from the excited state, we can trigger the emission of the ground state by optical feedback. We observe recurrent but incomplete switching between the two emission states by variation of the external cavity length in the sub-micrometer scale. We obtain a good qualitative agreement of experimental results with simulation results obtained by a rate equation that accounts for the variations of the feedback phase.

  5. Rotational Spectrum of 1,1-Difluoroethane: Internal Rotation Analysis and Structure

    NASA Astrophysics Data System (ADS)

    Villamanan, R. M.; Chen, W. D.; Wlodarczak, G.; Demaison, J.; Lesarri, A. G.; Lopez, J. C.; Alonso, J. L.

    1995-05-01

    The rotational spectrum of CH3CHF2 in its ground state was measured up to 653 GHz. Accurate rotational and centrifugal distortion constants were determined. The internal rotation splittings were analyzed using the internal axis method. An ab initio structure has been calculated and a near-equilibrium structure has been estimated using offsets derived empirically. This structure was compared to an experimental r0 structure. The four lowest excited states (including the methyl torsion) have also been assigned.

  6. Coherent libration to coherent rotational dynamics via chimeralike states and clustering in a Josephson junction array

    NASA Astrophysics Data System (ADS)

    Mishra, Arindam; Saha, Suman; Hens, Chittaranjan; Roy, Prodyot K.; Bose, Mridul; Louodop, Patrick; Cerdeira, Hilda A.; Dana, Syamal K.

    2017-01-01

    An array of excitable Josephson junctions under a global mean-field interaction and a common periodic forcing shows the emergence of two important classes of coherent dynamics, librational and rotational motion, in the weaker and stronger coupling limits, respectively, with transitions to chimeralike states and clustered states in the intermediate coupling range. In this numerical study, we use the Kuramoto complex order parameter and introduce two measures, a libration index and a clustering index, to characterize the dynamical regimes and their transitions and locate them in a parameter plane.

  7. Ground-state properties of hcp helium-4 on the basis of a cell model

    NASA Technical Reports Server (NTRS)

    Jacobi, N.; Zmuidzinas, J. S.

    1977-01-01

    A simple cell model is used to compute the ground-state energy and the volume-pressure relation for hcp He-4, in good agreement with experiments and with more sophisticated quantum mechanical calculations.

  8. Trajectory approach to the Schrödinger–Langevin equation with linear dissipation for ground states

    SciTech Connect

    Chou, Chia-Chun

    2015-11-15

    The Schrödinger–Langevin equation with linear dissipation is integrated by propagating an ensemble of Bohmian trajectories for the ground state of quantum systems. Substituting the wave function expressed in terms of the complex action into the Schrödinger–Langevin equation yields the complex quantum Hamilton–Jacobi equation with linear dissipation. We transform this equation into the arbitrary Lagrangian–Eulerian version with the grid velocity matching the flow velocity of the probability fluid. The resulting equation is simultaneously integrated with the trajectory guidance equation. Then, the computational method is applied to the harmonic oscillator, the double well potential, and the ground vibrational state of methyl iodide. The excellent agreement between the computational and the exact results for the ground state energies and wave functions shows that this study provides a synthetic trajectory approach to the ground state of quantum systems.

  9. Analytic models for the density of a ground-state spinor condensate

    NASA Astrophysics Data System (ADS)

    Gautam, Sandeep; Adhikari, S. K.

    2015-08-01

    We demonstrate that the ground state of a trapped spin-1 and spin-2 spinor ferromagnetic Bose-Einstein condensate (BEC) can be well approximated by a single decoupled Gross-Pitaevskii (GP) equation. Useful analytic models for the ground-state densities of ferromagnetic BECs are obtained from the Thomas-Fermi approximation (TFA) to this decoupled equation. Similarly, for the ground states of spin-1 antiferromagnetic and spin-2 antiferromagnetic and cyclic BECs, some of the spin-component densities are zero, which reduces the coupled GP equation to a simple reduced form. Analytic models for ground-state densities are also obtained for antiferromagnetic and cyclic BECs from the TFA to the respective reduced GP equations. The analytic densities are illustrated and compared with the full numerical solution of the GP equation with realistic experimental parameters.

  10. Coherent structures in the ground state of the quantum Frenkel-Kontorova model

    SciTech Connect

    Berman, G.P.; Bulgakov, E.N. Kirensky Institute of Physics, Research Educational Center for Nonlinear Processes at Krasnoyarsk Technical University, Theoretical Department at Krasnoyarsk State University, 660036, Krasnoyarsk ); Campbell, D.K. )

    1994-03-15

    We study the quantum ground state of the Frenkel-Kontorova model in the strongly nonlinear'' regime in which in the corresponding classical limit the coordinates of the atoms are distributed on Cantori.'' We identify (many) quasidegenerate configurations that contribute to the quantum ground state. When the characteristic quantum and classical energy scales are roughly equal (the intermediate'' quantum regime), we find, consistent with earlier numerical studies, that the standard map'' determining the coordinates in the classical ground state is renormalized to an effective sawtooth'' map, which determines the expectation values of the coordinates in the quantum ground state. We also discuss the dynamics of the model and estimate the characteristic time for various quantum tunneling effects.

  11. Features of simultaneous ground- and excited-state lasing in quantum dot lasers

    SciTech Connect

    Zhukov, A. E. Maximov, M. V.; Shernyakov, Yu. M.; Livshits, D. A.; Savelyev, A. V.; Zubov, F. I.; Klimenko, V. V.

    2012-02-15

    The lasing spectra and light-current (L-I) characteristics of an InAs/InGaAs quantum dot laser emitting in the simultaneous lasing mode at the ground- and excited-state optical transitions are studied. Lasing and spontaneous emission spectra are compared. It is shown that ground-state quenching of lasing is observed even in the absence of active region self-heating or an increase in homogeneous broadening with growth in the current density. It is found that the intensities of both lasing and spontaneous emission at the ground-state transition begin to decrease at a pump intensity that significantly exceeds the two-level lasing threshold. It is also found that different groups of quantum dots are involved in ground- and excited-state lasing.

  12. The impact of bonded interactions on the ground-state geometries of a small flexible polymer

    NASA Astrophysics Data System (ADS)

    Koci, Tomas; Qi, Kai; Bachmann, Michael

    2016-10-01

    Bonded interactions in coarse-grained models of elastic polymers are commonly represented by the finitely extensible nonlinear elastic (FENE) potential. In this study, we perform parallel multicanonical Monte Carlo simulations to examine the impact of an additional Lennard-Jones term in the bonded potential on the geometry of ground-state structures of a short polymer. Employing microcanonical inflection point analysis and conformational analysis, we construct a hyper-phase diagram and identify ground-state structures with two distinct geometries.

  13. Expectation values of single-particle operators in the random phase approximation ground state

    NASA Astrophysics Data System (ADS)

    Kosov, D. S.

    2017-02-01

    We developed a method for computing matrix elements of single-particle operators in the correlated random phase approximation ground state. Working with the explicit random phase approximation ground state wavefunction, we derived a practically useful and simple expression for a molecular property in terms of random phase approximation amplitudes. The theory is illustrated by the calculation of molecular dipole moments for a set of representative molecules.

  14. Ground state properties of solid and liquid spin-aligned atomic hydrogen

    NASA Technical Reports Server (NTRS)

    Danilowicz, R. L.; Dugan, J. V., Jr.; Etters, R. D.

    1976-01-01

    Calculations of the ground state energy in the solid phase were performed with the aid of a variational approach. The Morse potential form of the atomic triple potential computed by Kolos and Wolniewicz (1965) was employed for the calculations. The ground state energies of both the liquid and solid phases of spin-aligned atomic hydrogen around the volume of the transition are presented in a graph.

  15. Expectation values of single-particle operators in the random phase approximation ground state.

    PubMed

    Kosov, D S

    2017-02-07

    We developed a method for computing matrix elements of single-particle operators in the correlated random phase approximation ground state. Working with the explicit random phase approximation ground state wavefunction, we derived a practically useful and simple expression for a molecular property in terms of random phase approximation amplitudes. The theory is illustrated by the calculation of molecular dipole moments for a set of representative molecules.

  16. Using Diffusion Monte Carlo to Probe the Rotationally Excited States of H_3^+ and its Isotopologues

    NASA Astrophysics Data System (ADS)

    Wellen, Bethany A.; Petit, Andrew S.; McCoy, Anne B.

    2011-06-01

    H3-ND_n^+ are among the most abundant polyatomic ions in the universe. Moreover, the deuterated isotopologues are thought to play a key role in the astrochemical reactions governing the H/D fractionation of "metallic" species in the interstellar medium. An accurate quantum mechanical treatment of these species, as well as any reactions involving them, requires a methodology capable of capturing their large fluxionality as well as the constraints, due to particle exchange symmetries, on their physically allowed rovibrational states. Diffusion Monte Carlo (DMC) has been shown to be a highly successful technique for treating quantum zero-point effects of very floppy molecules and clusters and our group has recently developed a fixed-node DMC methodology capable of including the effects of rotational excitation. Here, we report the results of DMC calculations of the rotationally excited states of H_3^+ and its isotopologues. In particular, comparison with converged variational calculations involving states with J ≤ 20 provides the most thorough test yet of the range of quantum states over which the assumptions underlying our rotationally excited state DMC methodology can be reliably applied. Finally, the implications of this work on our overall goal of using DMC based methodologies to map out the energetics of the reaction of H3-ND_n^+ with HD will be discussed. T. R. Geballe and T. Oka, Science 312, 1610 (2006) E. Hugo, O. Asvany, and S. Schlemmer, J. Chem. Phys. 130, 164302 (2009) A. S. Petit and A. B. McCoy, J. Phys. Chem. A 113, 12706 (2009)

  17. Steady-State Computation of Constant Rotational Rate Dynamic Stability Derivatives

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Green, Lawrence L.

    2000-01-01

    Dynamic stability derivatives are essential to predicting the open and closed loop performance, stability, and controllability of aircraft. Computational determination of constant-rate dynamic stability derivatives (derivatives of aircraft forces and moments with respect to constant rotational rates) is currently performed indirectly with finite differencing of multiple time-accurate computational fluid dynamics solutions. Typical time-accurate solutions require excessive amounts of computational time to complete. Formulating Navier-Stokes (N-S) equations in a rotating noninertial reference frame and applying an automatic differentiation tool to the modified code has the potential for directly computing these derivatives with a single, much faster steady-state calculation. The ability to rapidly determine static and dynamic stability derivatives by computational methods can benefit multidisciplinary design methodologies and reduce dependency on wind tunnel measurements. The CFL3D thin-layer N-S computational fluid dynamics code was modified for this study to allow calculations on complex three-dimensional configurations with constant rotation rate components in all three axes. These CFL3D modifications also have direct application to rotorcraft and turbomachinery analyses. The modified CFL3D steady-state calculation is a new capability that showed excellent agreement with results calculated by a similar formulation. The application of automatic differentiation to CFL3D allows the static stability and body-axis rate derivatives to be calculated quickly and exactly.

  18. Ground-State Phases of Anisotropic Mixed Diamond Chains with Spins 1 and 1/2

    NASA Astrophysics Data System (ADS)

    Hida, Kazuo

    2014-11-01

    The ground-state phases of anisotropic mixed diamond chains with spins 1 and 1/2 are investigated. Both single-site and exchange anisotropies are considered. We find the phases consisting of an array of uncorrelated spin-1 clusters separated by singlet dimers. Except in the simplest case where the cluster consists of a single S = 1 spin, this type of ground state breaks the translational symmetry spontaneously. Although the mechanism leading to this type of ground state is the same as that in the isotropic case, it is nonmagnetic or paramagnetic depending on the competition between two types of anisotropy. We also find the Néel, period-doubled Néel, Haldane, and large-D phases, where the ground state is a single spin cluster of infinite size equivalent to the spin-1 Heisenberg chain with alternating anisotropies. The ground-state phase diagrams are determined for typical sets of parameters by numerical analysis. In various limiting cases, the ground-state phase diagrams are determined analytically. The low-temperature behaviors of magnetic susceptibility and entropy are investigated to distinguish each phase by observable quantities. The relationship of the present model with the anisotropic rung-alternating ladder with spin-1/2 is also discussed.

  19. Ground states of the Ising model on an anisotropic triangular lattice: stripes and zigzags.

    PubMed

    Dublenych, Yu I

    2013-10-09

    A complete solution of the ground-state problem for the Ising model on an anisotropic triangular lattice with the nearest-neighbor interactions in a magnetic field is presented. It is shown that this problem can be reduced to the ground-state problem for an infinite chain with the interactions up to the second neighbors. In addition to the known ground-state structures (which correspond to full-dimensional regions in the parameter space of the model), new structures are found (at the boundaries of these regions), in particular, zigzagging stripes similar to those observed experimentally in colloidal monolayers. Though the number of parameters is relatively large (four), all the ground-state structures of the model are constructed and analyzed and therefore the paper can be considered as an example of a complete solution of a ground-state problem for classical spin or lattice-gas models. The paper can also help to verify the correctness of some results obtained previously by other authors and concerning the ground states of the model under consideration.

  20. Relativistic configuration interaction calculation on the ground and excited states of iridium monoxide

    SciTech Connect

    Suo, Bingbing; Yu, Yan-Mei; Han, Huixian

    2015-03-07

    We present the fully relativistic multi-reference configuration interaction calculations of the ground and low-lying excited electronic states of IrO for individual spin-orbit component. The lowest-lying state is calculated for Ω = 1/2, 3/2, 5/2, and 7/2 in order to clarify the ground state of IrO. Our calculation suggests that the ground state is of Ω = 1/2, which is highly mixed with {sup 4}Σ{sup −} and {sup 2}Π states in Λ − S notation. The two low-lying states 5/2 and 7/2 are nearly degenerate with the ground state and locate only 234 and 260 cm{sup −1} above, respectively. The equilibrium bond length 1.712 Å and the harmonic vibrational frequency 903 cm{sup −1} of the 5/2 state are close to the experimental measurement of 1.724 Å and 909 cm{sup −1}, which suggests that the 5/2 state should be the low-lying state that contributes to the experimental spectra. Moreover, the electronic states that give rise to the observed transition bands are assigned for Ω = 5/2 and 7/2 in terms of the obtained excited energies and oscillator strengths.

  1. Terahertz spectroscopy on Faraday and Kerr rotations in a quantum anomalous Hall state

    PubMed Central

    Okada, Ken N.; Takahashi, Youtarou; Mogi, Masataka; Yoshimi, Ryutaro; Tsukazaki, Atsushi; Takahashi, Kei S.; Ogawa, Naoki; Kawasaki, Masashi; Tokura, Yoshinori

    2016-01-01

    Electrodynamic responses from three-dimensional topological insulators are characterized by the universal magnetoelectric term constituent of the Lagrangian formalism. The quantized magnetoelectric coupling, which is generally referred to as topological magnetoelectric effect, has been predicted to induce exotic phenomena including the universal low-energy magneto-optical effects. Here we report the experimental indication of the topological magnetoelectric effect, which is exemplified by magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall states of magnetic topological insulator surfaces by terahertz magneto-optics. The universal relation composed of the observed Faraday and Kerr rotation angles but not of any material parameters (for example, dielectric constant and magnetic susceptibility) well exhibits the trajectory towards the fine structure constant in the quantized limit. PMID:27436710

  2. Terahertz spectroscopy on Faraday and Kerr rotations in a quantum anomalous Hall state.

    PubMed

    Okada, Ken N; Takahashi, Youtarou; Mogi, Masataka; Yoshimi, Ryutaro; Tsukazaki, Atsushi; Takahashi, Kei S; Ogawa, Naoki; Kawasaki, Masashi; Tokura, Yoshinori

    2016-07-20

    Electrodynamic responses from three-dimensional topological insulators are characterized by the universal magnetoelectric term constituent of the Lagrangian formalism. The quantized magnetoelectric coupling, which is generally referred to as topological magnetoelectric effect, has been predicted to induce exotic phenomena including the universal low-energy magneto-optical effects. Here we report the experimental indication of the topological magnetoelectric effect, which is exemplified by magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall states of magnetic topological insulator surfaces by terahertz magneto-optics. The universal relation composed of the observed Faraday and Kerr rotation angles but not of any material parameters (for example, dielectric constant and magnetic susceptibility) well exhibits the trajectory towards the fine structure constant in the quantized limit.

  3. New clues on the interior of Titan from its rotation state

    NASA Astrophysics Data System (ADS)

    Noyelles, Benoît; Nimmo, Francis

    2014-07-01

    The Saturnian satellite Titan is one of the main targets of the Cassini-Huygens mission, which revealed in particular Titan's shape, gravity field, and rotation state. The shape and gravity field suggest that Titan is not in hydrostatic equilibrium, that it has a global subsurface ocean, and that its ice shell is both rigid (at tidal periods) and of variable thickness. The rotational state of Titan consists of an expected synchronous rotation rate and an unexpectedly high obliquity (0.3○) explained by Baland et al. (2011) to be a resonant behavior. We here combine a realistic model of the ice shell and interior and a 6-degrees of freedom rotational model, in which the librations, obliquity and polar motion of the rigid core and of the shell are modelled, to constrain the structure of Titan from the observations. We consider the gravitational pull of Saturn on the 2 rigid layers, the gravitational coupling between them, and the pressure coupling at the liquid-solid interfaces. We confirm the influence of the resonance found by Baland et al., that affects between 10 and 13% of the possible Titans. It is due to the 29.5-year periodic annual forcing. The resonant Titans can be obtained in situations in which a mass anomaly at the shell-ocean boundary (bottom loading) is from 80 to 92% compensated. This suggests a 250 to 280 km thick ocean below a 130 to 140 km thick shell, and is consistent with the degree-3 analysis of Hemingway 26 et al. (2013).

  4. Bound state potential energy surface construction: ab initio zero-point energies and vibrationally averaged rotational constants.

    PubMed

    Bettens, Ryan P A

    2003-01-15

    Collins' method of interpolating a potential energy surface (PES) from quantum chemical calculations for reactive systems (Jordan, M. J. T.; Thompson, K. C.; Collins, M. A. J. Chem. Phys. 1995, 102, 5647. Thompson, K. C.; Jordan, M. J. T.; Collins, M. A. J. Chem. Phys. 1998, 108, 8302. Bettens, R. P. A.; Collins, M. A. J. Chem. Phys. 1999, 111, 816) has been applied to a bound state problem. The interpolation method has been combined for the first time with quantum diffusion Monte Carlo calculations to obtain an accurate ground state zero-point energy, the vibrationally average rotational constants, and the vibrationally averaged internal coordinates. In particular, the system studied was fluoromethane using a composite method approximating the QCISD(T)/6-311++G(2df,2p) level of theory. The approach adopted in this work (a) is fully automated, (b) is fully ab initio, (c) includes all nine nuclear degrees of freedom, (d) requires no assumption of the functional form of the PES, (e) possesses the full symmetry of the system, (f) does not involve fitting any parameters of any kind, and (g) is generally applicable to any system amenable to quantum chemical calculations and Collins' interpolation method. The calculated zero-point energy agrees to within 0.2% of its current best estimate. A0 and B0 are within 0.9 and 0.3%, respectively, of experiment.

  5. Equilibrium states and ground state of two-dimensional fluid foams

    SciTech Connect

    Graner, F.; Jiang, Y.; Janiaud, E.; Flament, C.

    2001-01-01

    We study the equilibrium energies of two-dimensional (2D) noncoarsening fluid foams, which consist of bubbles with fixed areas. The equilibrium states correspond to local minima of the total perimeter. We present a theoretical derivation of energy minima; experiments with ferrofluid foams, which can be either highly distorted, locally relaxed, or globally annealed; and Monte Carlo simulations using the extended large-Q Potts model. For a dry foam with small size variance we develop physical insight and an electrostatic analogy, which enables us to (i) find an approximate value of the global minimum perimeter, accounting for (small) area disorder, the topological distribution, and physical boundary conditions; (ii) conjecture the corresponding pattern and topology: small bubbles sort inward and large bubbles sort outward, topological charges of the same signs ''repel'' while charges of the opposite signs ''attract;'' (iii) define local and global markers to determine directly from an image how far a foam is from its ground state; (iv) conjecture that, in a local perimeter minimum at prescribed topology, the pressure distribution and thus the edge curvature are unique. Some results also apply to 3D foams.

  6. Ordered ground states of metallic hydrogen and deuterium

    NASA Technical Reports Server (NTRS)

    Ashcroft, N. W.

    1981-01-01

    The physical attributes of some of the more physically distinct ordered states of metallic hydrogen and metallic deuterium at T = 0 and nearby are discussed. The likelihood of superconductivity in both is considered with respect to the usual coupling via the density fluctuations of the ions.

  7. Sharing Common Ground: Texas and the Common Core State Standards

    ERIC Educational Resources Information Center

    Vasinda, Sheri; Grote-Garcia, Stephanie; Durham, Patricia

    2013-01-01

    When browsing through professional catalogs or attending national conferences, one cannot help but notice the growing emphasis on the Common Core State Standards (CCSS). So, what does this mean for Texas teachers? As part of a special four-part series in our Texas Journal of Literacy Education, a special task force from the TALE Board will share…

  8. Periodic ground state for the charged massive Schwinger model

    SciTech Connect

    Nagy, S.; Sailer, K.; Polonyi, J.

    2004-11-15

    It is shown that the charged massive Schwinger model supports a periodic vacuum structure for arbitrary charge density, similar to the common crystalline layout known in solid state physics. The dynamical origin of the inhomogeneity is identified in the framework of the bosonized model and in terms of the original fermionic variables.

  9. Ab initio dipole moment and theoretical rovibrational intensities in the electronic ground state of PH 3

    NASA Astrophysics Data System (ADS)

    Yurchenko, Sergei N.; Carvajal, Miguel; Thiel, Walter; Jensen, Per

    2006-09-01

    We report a six-dimensional CCSD(T)/aug-cc-pVTZ dipole moment surface for the electronic ground state of PH 3 computed ab initio on a large grid of 10 080 molecular geometries. Parameterized, analytical functions are fitted through the ab initio data, and the resulting dipole moment functions are used, together with a potential energy function determined by refining an existing ab initio surface in fittings to experimental wavenumber data, for simulating absorption spectra of the first three polyads of PH 3, i.e., ( ν2, ν4), ( ν1, ν3, 2 ν2, 2 ν4, ν2 + ν4), and ( ν1 + ν2, ν3 + ν2, ν1 + ν4, ν3 + ν4, 2 ν2 + ν4, ν2 + 2 ν4, 3 ν2, 3 ν4). The resulting theoretical transition moments show excellent agreement with experiment. A line-by-line comparison of the simulated intensities of the ν2/ ν4 band system with 955 experimental intensity values reported by Brown et al. [L.R. Brown, R.L. Sams, I. Kleiner, C. Cottaz, L. Sagui, J. Mol. Spectrosc. 215 (2002) 178-203] gives an average absolute percentage deviation of 8.7% (and a root-mean-square deviation of 0.94 cm -1 for the transition wavenumbers). This is very remarkable since the calculations rely entirely on ab initio dipole moment surfaces and do not involve any adjustment of these surfaces to reproduce the experimental intensities. Finally, we predict the line strengths for transitions between so-called cluster levels (near-degenerate levels formed at high rotational excitation) for J up to 60.

  10. Ground state of Ho atoms on Pt(111) metal surfaces: Implications for magnetism

    NASA Astrophysics Data System (ADS)

    Karbowiak, M.; Rudowicz, C.

    2016-05-01

    We investigated the ground state of Ho atoms adsorbed on the Pt(111) surface, for which conflicting results exist. The density functional theory (DFT) calculations yielded the Ho ground state as | Jz=±8 > . Interpretation of x-ray absorption spectroscopy and x-ray magnetic circular dichroism spectra and the magnetization curves indicated the ground state as | Jz=±6 > . Superposition model is employed to predict the crystal-field (CF) parameters based on the structural data for the system Ho/Pt(111) obtained from the DFT modeling. Simultaneous diagonalization of the free-ion (HFI) and the trigonal CF Hamiltonian (HCF) within the whole configuration 4 f10 of H o3 + ion was performed. The role of the trigonal CF terms, neglected in the pure uniaxial CF model used previously for interpretation of experimental spectra, is found significant, whereas the sixth-rank CF terms may be neglected in agreement with the DFT predictions. The results provide substantial support for the experimental designation of the | Jz=±6 > ground state, albeit with subtle difference due to admixture of other | Jz> states, but run against the DFT-based designation of the | Jz=±8 > ground state. A subtle splitting of the ground energy level with the state (predominantly), | Jz=±6 > is predicted. This paper provides better insight into the single-ion magnetic behavior of the Ho/Pt(111) system by helping to resolve the controversy concerning the Ho ground state. Experimental techniques with greater resolution powers are suggested for direct confirmation of this splitting and C3 v symmetry experienced by the Ho atom.

  11. Degenerate ground states and multiple bifurcations in a two-dimensional q-state quantum Potts model.

    PubMed

    Dai, Yan-Wei; Cho, Sam Young; Batchelor, Murray T; Zhou, Huan-Qiang

    2014-06-01

    We numerically investigate the two-dimensional q-state quantum Potts model on the infinite square lattice by using the infinite projected entangled-pair state (iPEPS) algorithm. We show that the quantum fidelity, defined as an overlap measurement between an arbitrary reference state and the iPEPS ground state of the system, can detect q-fold degenerate ground states for the Z_{q} broken-symmetry phase. Accordingly, a multiple bifurcation of the quantum ground-state fidelity is shown to occur as the transverse magnetic field varies from the symmetry phase to the broken-symmetry phase, which means that a multiple-bifurcation point corresponds to a critical point. A (dis)continuous behavior of quantum fidelity at phase transition points characterizes a (dis)continuous phase transition. Similar to the characteristic behavior of the quantum fidelity, the magnetizations, as order parameters, obtained from the degenerate ground states exhibit multiple bifurcation at critical points. Each order parameter is also explicitly demonstrated to transform under the Z_{q} subgroup of the symmetry group of the Hamiltonian. We find that the q-state quantum Potts model on the square lattice undergoes a discontinuous (first-order) phase transition for q=3 and q=4 and a continuous phase transition for q=2 (the two-dimensional quantum transverse Ising model).

  12. Determination and Comparison of Carbonyl Stretching Frequency of a Ketone in Its Ground State and the First Electronic Excited State

    ERIC Educational Resources Information Center

    Bandyopadhyay, Subhajit; Roy, Saswata

    2014-01-01

    This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…

  13. Rotational branching ratios and photoelectron angular distributions in resonance enhanced multiphoton ionization of HBr via the F sup 1. Delta. sub 2 Rydberg state

    SciTech Connect

    Wang, K.; McKoy, V. )

    1991-12-01

    Results of theoretical studies of rotational ion distributions in the {ital X} {sup 2}{Pi}{sub 1/2} ground state of HBr{sup +} resulting from (2+1) resonance enhanced multiphoton ionization (REMPI) via the {ital S}(2) branch of the {ital F} {sup 1}{Delta}{sub 2} Rydberg state are reported. These results show a strongly parity-favored ion distribution with about 80% population in the ({minus}) component of the {Lambda} doublet of {ital J}{sup +} rotational levels. The 20% population in the other parity component of the {Lambda} doublet can be seen to be due to odd partial wave contributions to the photoelectron matrix elements which arise primarily from non-atomic-like behavior of the electronic continuum. This, in turn, is due to angular momentum coupling in the photoelectron orbital brought about by the torques of the nonspherical molecular ion potential. We demonstrate that the effect of alignment on these ion distributions, although not large, is important. Photoelectron angular distributions and alignment of the {ital J} levels of the HBr{sup +} ions are also presented. Rotational branching ratios and photoelectron angular distributions resulting from (2+1{prime}) REMPI of HBr via several {ital S} branches of the {ital F} {sup 1}{Delta}{sub 2} state are also shown for near-threshold photoelectron energies.

  14. Ground-Water Recharge in Humid Areas of the United States--A Summary of Ground-Water Resources Program Studies, 2003-2006

    USGS Publications Warehouse

    Delin, Geoffrey N.; Risser, Dennis W.

    2007-01-01

    Increased demands on water resources by a growing population and recent droughts have raised awareness about the adequacy of ground-water resources in humid areas of the United States. The spatial and temporal variability of ground-water recharge are key factors that need to be quantified to determine the sustainability of ground-water resources. Ground-water recharge is defined herein as the entry into the saturated zone of water made available at the water-table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry, 1979). In response to the need for better estimates of ground-water recharge, the Ground-Water Resources Program (GWRP) of the U.S. Geological Survey (USGS) began an initiative in 2003 to estimate ground-water recharge rates in the relatively humid areas of the United States.

  15. Making Classical Ground State Spin Computing Fault-Tolerant

    DTIC Science & Technology

    2010-06-24

    teleportation ,” Phys. Rev. A, 70 (2004). [15] D. Aharonov, W. van Dam, J. Kempe, Z. Landau, S. Lloyd, and O. Regev, “Adiabatic quantum computation is equiv...Adiabatic gate teleportation ,” Phys. Rev. Lett., 103, 120504 (2009). [25] D. Bacon and S. T. Flammia, “Adiabatic cluster state quantum computing...is relevant to quantum dot cellular automata as well as to recent universal adiabatic quantum computing constructions. In its most primitive form

  16. Methods and Indicators for Assessment of Regional Ground-Water Conditions in the Southwestern United States

    USGS Publications Warehouse

    Tillman, Fred D; Leake, Stanley A.; Flynn, Marilyn E.; Cordova, Jeffrey T.; Schonauer, Kurt T.; Dickinson, Jesse E.

    2008-01-01

    Monitoring the status and trends in the availability of the Nation's ground-water supplies is important to scientists, planners, water managers, and the general public. This is especially true in the semiarid to arid southwestern United States where rapid population growth and limited surface-water resources have led to increased use of ground-water supplies and water-level declines of several hundred feet in many aquifers. Individual well observations may only represent aquifer conditions in a limited area, and wells may be screened over single or multiple aquifers, further complicating single-well interpretations. Additionally, changes in ground-water conditions may involve time scales ranging from days to many decades, depending on the timing of recharge, soil and aquifer properties, and depth to the water table. The lack of an easily identifiable ground-water property indicative of current conditions, combined with differing time scales of water-level changes, makes the presentation of ground-water conditions a difficult task, particularly on a regional basis. One approach is to spatially present several indicators of ground-water conditions that address different time scales and attributes of the aquifer systems. This report describes several methods and indicators for presenting differing aspects of ground-water conditions using water-level observations in existing data-sets. The indicators of ground-water conditions developed in this study include areas experiencing water-level decline and water-level rise, recent trends in ground-water levels, and current depth to ground water. The computer programs written to create these indicators of ground-water conditions and display them in an interactive geographic information systems (GIS) format are explained and results illustrated through analyses of ground-water conditions for selected alluvial basins in the Lower Colorado River Basin in Arizona.

  17. Exponentially Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians

    NASA Astrophysics Data System (ADS)

    Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G.

    2017-02-01

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009), 10.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  18. Exponentially Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians.

    PubMed

    Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G

    2017-02-17

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009)NJOPFM1367-263010.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  19. Observation of γ-vibrations and alignments built on non-ground-state configurations in ¹⁵⁶Dy

    DOE PAGES

    Zhu, C. -H.; Hartley, D. J.; Riedinger, L. L.; ...

    2015-03-26

    The exact nature of the lowest Kπ=2⁺ rotational bands in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the γ degree of freedom perpendicular to the nuclear symmetry axis. Very few such γ-bands have been traced past the usual back-bending rotational alignments of high-j nucleons. We have investigated the structure of positive-parity bands in the N=90 nucleus ¹⁵⁶Dy, using the ¹⁴⁸Nd(¹²C,4n)¹⁵⁶Dy reaction at 65 MeV, observing the resulting γ-ray transitions with the Gammasphere array. The even- and odd-spin members of the π=2⁺ γ-band are observed to 32⁺ and 31⁺ respectively.more » This rotational band faithfully tracks the ground-state configuration to the highest spins. The members of a possible γ-vibration built on the aligned yrast S-band are observed to spins 28⁺ and 27⁺. An even-spin positive-parity band, observed to spin 24⁺, is a candidate for an aligned S-band built on the seniority-zero configuration of the 0₂⁺ state at 676 keV. As a result, the crossing of this band with the 0₂⁺ band is at hwc = 0.28(1) MeV and is consistent with the configuration of the 0₂⁺ band not producing any blocking of the monopole pairing.« less

  20. Observation of γ-vibrations and alignments built on non-ground-state configurations in ¹⁵⁶Dy

    SciTech Connect

    Zhu, C. -H.; Hartley, D. J.; Riedinger, L. L.; Sharpey-Schafer, J. F.; Almond, J. M.; Beausang, C.; Carpenter, M. P.; Chiara, C. J.; Cooper, N.; Curien, D.; Gall, B. J. P.; Garrett, P. E.; Janssens, R. V. F.; Kondev, F. G.; Kulp, W. D.; Lauritsen, T.; McCutchan, E. A.; Miller, D.; Piot, J.; Redon, N.; Riley, M. A.; Simpson, J.; Stefanescu, I.; Werner, V.; Wang, X.; Wood, J. L.; Majola, S. N. T.; Zhu, S.

    2015-03-26

    The exact nature of the lowest Kπ=2⁺ rotational bands in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the γ degree of freedom perpendicular to the nuclear symmetry axis. Very few such γ-bands have been traced past the usual back-bending rotational alignments of high-j nucleons. We have investigated the structure of positive-parity bands in the N=90 nucleus ¹⁵⁶Dy, using the ¹⁴⁸Nd(¹²C,4n)¹⁵⁶Dy reaction at 65 MeV, observing the resulting γ-ray transitions with the Gammasphere array. The even- and odd-spin members of the π=2⁺ γ-band are observed to 32⁺ and 31⁺ respectively. This rotational band faithfully tracks the ground-state configuration to the highest spins. The members of a possible γ-vibration built on the aligned yrast S-band are observed to spins 28⁺ and 27⁺. An even-spin positive-parity band, observed to spin 24⁺, is a candidate for an aligned S-band built on the seniority-zero configuration of the 0₂⁺ state at 676 keV. As a result, the crossing of this band with the 0₂⁺ band is at hwc = 0.28(1) MeV and is consistent with the configuration of the 0₂⁺ band not producing any blocking of the monopole pairing.

  1. Quantum state tomography for quadrupolar nuclei using global rotations of the spin system.

    PubMed

    Teles, J; deAzevedo, E R; Auccaise, R; Sarthour, R S; Oliveira, I S; Bonagamba, T J

    2007-04-21

    In this paper, we describe a quantum state tomography method based on global rotations of the spin system which, together with a coherence selection scheme, enables the complete density matrix reconstruction. The main advantage of this technique, in respect to previous proposals, is the use of much shorter rf pulses, which decreases significantly the time necessary for algorithm quantum state tomography. In this case, under adequate experimental conditions, the rf pulses correspond to simple spatial rotations of the spin states, and its analytical description is conveniently given in the irreducible tensor formalism. Simulated results show the feasibility of the method for a single spin 72 nucleus. As an experimental result, we exemplify the application of this method by tomographing the steps during the implementation of the Deutsch algorithm. The algorithm was implemented in a (23)Na quadrupole nucleus using the strongly modulated pulses technique. We also extended the tomography method for a 3-coupled homonuclear spin 12 system, where an additional evolution under the internal Hamiltonian is necessary for zero order coherences evaluation.

  2. Rotational 2+ states of superheavy elements in the Skyrme-Hartree-Fock-Bogoliubov model

    NASA Astrophysics Data System (ADS)

    Baran, A.; Staszczak, A.

    2013-05-01

    The Skyrme-Hartree-Fock-Bogoliubov calculations of the energies of first 2+ rotational states of deformed superheavy (SH) elements in the region of 108 ⩽ Z ⩽ 126 and 148 ⩽ N ⩽ 180 are reported. The results agree well in the case of fermium isotopes after a proper scaling of the moment of inertia. The scaling factor equals 1.3. The extension of the model to the region of SH elements gives a possibility of better estimation of the Q-values of α-decay, which is a dominant decay mode of SH elements.

  3. Theoretical Calculations of XeF Ground State Kinetics.

    DTIC Science & Technology

    1988-03-01

    APPRVE FO PBC ELAE;AP 5981 This report was submitted by The Aerospace Corporation , El Segundo, CA 90245, under Contract No. F0701-85-C-0086-PO0016 with...the Space Division, P.O. Box 92960, Worldway Postal Center, Los Angeles, CA 90009-2960. It was reviewed and approved for The Aerospace Corporation by W...a. NAME OF MONITORING ORGANIZATION The Aerospace Corporation ( Space Division Laboratory Operations 6C. ADDRESS (Cly, State, and ZP Code) 7b ADDRESS

  4. Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

    PubMed

    Robinson, A P; Woods, P J; Seweryniak, D; Davids, C N; Carpenter, M P; Hecht, A A; Peterson, D; Sinha, S; Walters, W B; Zhu, S

    2005-07-15

    Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.

  5. Quantal Density Functional Theory(Q-DFT) of Degenerate Ground and Excited States

    NASA Astrophysics Data System (ADS)

    Sahni, Viraht; Pan, Xiaoyin

    2002-03-01

    We present here Q-DFT (V.Sahni et al, PRL 87), 113002 (2001), and references therein. of degenerate states with degeneracy g. We describe : (a) The transformation from a degenerate ground or excited pure state of the interacting system to an S (single Slater determinant) system of noninteracting Fermions with equivalent density, total energy, and ionization potential; (b) The construction of g S systems to reproduce a subspace ensemble density and energy. The density and energy are defined via the ensemble density matrix formed from the degenerate ground or excited pure states of the interacting system; (c) The construction of an S system with a g-fold degenerate highest occupied level, (which leads to g Slater determinants (C.A. Ullrich and W. Kohn, PRL 87), 093001(2001).), to reproduce the ground or excited state ensemble density and energy.

  6. Ground state of the hydrogen molecule in a strong magnetic field

    NASA Astrophysics Data System (ADS)

    Kravchenko, Yu. P.; Liberman, M. A.

    1997-10-01

    The ground state of a hydrogen molecule in magnetic fields is investigated using a fully numerical Hartree-Fock approach. We found that between 4.2×104 T and 3×106 T the ground state is 3Σ+u with very weak interaction between atoms. In this field region the hydrogen can form a superfluid phase, predicted earlier [Korolev and Liberman, Phys. Rev. Lett. 72, 270 (1994)]; the state 3Πu is metastable and may be responsible for the unknown excitonic line observed by Timofeev and Chernenko [JETP Lett. 61, 617 (1995)]. For magnetic fields stronger than 3×106 T the ground state is the tightly bound 3Πu.

  7. Uniqueness of Positive Ground State Solutions of the Logarithmic Schrödinger Equation

    NASA Astrophysics Data System (ADS)

    Troy, William C.

    2016-12-01

    We prove the uniqueness of positive ground state solutions of the problem { {{d2u}/{dr2}} + {{n-1}/{r}}{du/dr}} + u ln(|u|) = 0}, {u(r) > 0 forall r ≥ 0}, and {(u(r),u'(r)) to (0, 0)} as {r to ∞}. This equation is derived from the logarithmic Schrödinger equation {iψt = {Δ} ψ + u ln (|u|2)}, and also from the classical equation {{{partial u}/{partial t}} = {Δ} u +u (|u|^{p-1}) -u}. For each {n ≥ 1}, a positive ground state solution is { u0(r) = exp (-{r^2/4} + {n/2}), 0 ≤ r < ∞}. We combine {u0(r)} with energy estimates and associated Ricatti equation estimates to prove that, for each {n in [1, 9 ]}, {u0(r)} is the only positive ground state. We also investigate the stability of {u0(r)}. Several open problems are stated.

  8. Charge ordered normal ground state and its interplay with superconductivity in the underdoped cuprates

    NASA Astrophysics Data System (ADS)

    Sebastian, Suchitra

    2015-03-01

    Over the last few years, evidence has gradually built for a charge ordered normal ground state in the underdoped region of the cuprate high temperature superconductors. I will address the electronic structure of the normal ground state of the underdoped cuprates as accessed by quantum oscillations, and relate it to complementary measurements by other experimental techniques. The interplay of the charge ordered ground state with the antinodal gapped pseudogap state, and overarching magnetic and superconducting correlations will be further explored. This work was performed in collaboration with N. Harrison, G. G. Lonzarich, B. J. Ramshaw, B. S. Tan, P. A. Goddard, F. F. Balakirev, C. H. Mielke, R. Liang, D. A. Bonn, and W. N. Hardy

  9. Learning Approach on the Ground State Energy Calculation of Helium Atom

    SciTech Connect

    Shah, Syed Naseem Hussain

    2010-07-28

    This research investigated the role of learning approach on the ground state energy calculation of Helium atom in improving the concepts of science teachers at university level. As the exact solution of several particles is not possible here we used approximation methods. Using this method one can understand easily the calculation of ground state energy of any given function. Variation Method is one of the most useful approximation methods in estimating the energy eigen values of the ground state and the first few excited states of a system, which we only have a qualitative idea about the wave function.The objective of this approach is to introduce and involve university teacher in new research, to improve their class room practices and to enable teachers to foster critical thinking in students.

  10. Correlations between ground and excited state spectra of a quantum Dot

    PubMed

    Stewart; Sprinzak; Marcus; Duruoz; Harris

    1997-12-05

    The ground and excited state spectra of a semiconductor quantum dot with successive electron occupancy were studied with linear and nonlinear magnetoconductance measurements. A direct correlation was observed between the mth excited state of the N-electron system and the ground state of the (N + m)-electron system for m up to 4. The results are consistent with a single-particle picture in which a fixed spectrum of energy levels is successively filled, except for a notable absence of spin degeneracy. Further departures from the single-particle picture due to electron-electron interaction were also observed. Magnetoconductance fluctuations of ground states show anticrossings where wave function characteristics are exchanged between adjacent levels.

  11. Short-range correlations in the magnetic ground state of Na4 Ir3 O8

    NASA Astrophysics Data System (ADS)

    Dally, Rebecca; Hogan, Tom; Amato, Alex; Luetkens, Hubertus; Baines, Chris; Rodriguez-Rivera, Jose; Graf, Michael; Wilson, Stephen

    2015-03-01

    The magnetic ground state of the candidate three-dimensional quantum spin liquid Na4 Ir3O8 has been studied through bulk magnetization, muon spin relaxation and neutron scattering measurements. Na4 Ir3O8 possesses a unique hyper-Kagome lattice of Ir moments that is potentially accompanied by a novel realization of Heisenberg-Kitaev exchange. This fact combined with the absence of previously reported magnetic ordering has led to its candidacy as a three-dimensional quantum spin liquid. Our combined experimental data show that a short-range, frozen, ground state comprised of quasi-static moments develops in this material below a characteristic temperature TF = 6 K , persisting down until at least 20 mK. The expected dynamical ground state of a quantum spin liquid was not observed but rather an inhomogeneous quasi-static spin state that survives with persistent long timescale fluctuations.

  12. Exact many-electron ground states on the diamond Hubbard chain

    NASA Astrophysics Data System (ADS)

    Gulacsi, Zsolt; Kampf, Arno; Vollhardt, Dieter

    2008-03-01

    Exact ground states of interacting electrons on the diamond Hubbard chain in a magnetic field are constructed which exhibit a wide range of properties such as flat-band ferromagnetism, correlation induced metallic, half-metallic, or insulating behavior [1]. The properties of these ground states can be tuned by changing the magnetic flux, local potentials, or electron density.The results show that the studied simple one-dimensional structure displays remarkably complex physical properties. The virtue of tuning different ground states through external parameters points to new possibilities for the design of electronic devices which can switch between insulating or conducting and nonmagnetic or (fully or partially spin polarized) ferromagnetic states, open new routes for the design of spin-valve devices and gate induced ferromagnetism. [1] Z. Gulacsi, A. Kampf, D. Vollhardt, Phys. Rev. Lett. 99, 026404(2007).

  13. Repumping ground-state population in a coherently driven atomic resonance.

    PubMed

    Sinay, Asif; Shuker, Moshe; Firstenberg, Ofer; Fisher, Amnon; Ben-Kish, Amit; Steinhauer, Jeff

    2010-08-30

    We experimentally demonstrate an optical pumping technique to pump a dilute rubidium vapor into the m(F) = 0 ground states. The technique utilizes selection rules that forbid the excitation of the m(F) = 0 states by linearly-polarized light. A substantial increase in the transparency contrast of the coherent-population-trapping resonance used for frequency standards is demonstrated.

  14. Restrictions on Medicaid abortions open to challenge on state constitutional grounds.

    PubMed

    Klassel, D

    1980-12-01

    The United States Court (June 30, 1980) held in Harris v. McRae and Williams V. Zbaraz that the federal government and the states may refuse to pay for most abortions needed by Medicaid-eligible women without violating the Constitution. These decisions brought to an end litigation to establish a federal constitutional right to public aid for poor women in deciding whether to continue or terminate a pregnancy. Decisions of a state's highest court resting solely on state law grounds are usually not reviewed by the U.S. Supreme Court, leaving each state free to curve out unique areas of rights and liberties for its population. Attention is directed here to the manner in which state courts may do so in the area of public funding for abortion with focus on the following: abortion and abortion funding under the federal constitution; challenging abortion restrictions on state constitutional grounds; establishing a state constitutional right to abortion; establishing denial of the right to abortion; justifying the interference; discrimination on the basis of wealth; and sex discrimination. The challenging of abortion funding restrictions on state constitutional grounds is a promising legal strategy for advocates of abortion rights. It has increased the chances for success in states that show a willingness to expand on federal constitutional law precedents: states that recognize principles of neutrality in granting government benefits or that provide special constitutional protection to the poor and to women.

  15. Origin of the Tetragonal Ground State of Heusler Compounds

    NASA Astrophysics Data System (ADS)

    Faleev, Sergey V.; Ferrante, Yari; Jeong, Jaewoo; Samant, Mahesh G.; Jones, Barbara; Parkin, Stuart S. P.

    2017-03-01

    We describe the general mechanism of tetragonal distortion in Heusler compounds X2Y Z . From 286 compounds studied using density-functional theory, 62% are found to be tetragonal at zero temperature. Such a large share of compounds with tetragonal distortions can be explained by the peak-and-valley character of the density of states (DOS) of these compounds in the cubic phase (arising from localized d bands and van Hove singularities) in conjunction with a smooth shift of peaky DOS structure relative to the Fermi energy, EF, when valence electrons are added to the system. A shift of the DOS in the Y or Z series leads to an alternation of stable and nonstable cubic phases that depends on the value of the DOS at EF in the cubic phase. Groups of compounds with a large share of tetragonal distortions are identified and explained.

  16. Interactions Between Ground-State Nitrogen Atoms and Molecules

    NASA Technical Reports Server (NTRS)

    Vanderslice, Joseph T.; Mason, Edward A.; Lippincott, Ellis R.

    1959-01-01

    Potential-energy curves for nitrogen atom (N-N) interactions corresponding to the X (1)Sigma(sup +, sub g), A (3)Sigma(sup +, sub u), (5)Sigma(sup +, sub g), (7)Sigma(sup +, sub u), B (3) Pi(sub g), C (3)(Pi(su u)and a (1)Pi(sub g) states of the nitrogen molecule N2 as well as curves for the atom-molecules (N-N2) and molecule-molecule (N2-N2) interactions have been calculated. All calculations have been based as nearly as possible on experimental data, including spectroscopically determined vibrational energy levels, scattering cross sections of atomic beams in gases, and measured vibrational relaxation times. In cases where experimental data were not available, approximate quantum-mechanical calculations have been made. Results obtained by these various methods are remarkably consistent with one another and are believed to have good accuracy.

  17. Surface modification using low energy ground state ion beams

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1990-01-01

    A method of effecting modifications at the surfaces of materials using low energy ion beams of known quantum state, purity, flux, and energy is presented. The ion beam is obtained by bombarding ion-generating molecules with electrons which are also at low energy. The electrons used to bombard the ion generating molecules are separated from the ions thus obtained and the ion beam is directed at the material surface to be modified. Depending on the type of ion generating molecules used, different ions can be obtained for different types of surface modifications such as oxidation and diamond film formation. One area of application is in the manufacture of semiconductor devices from semiconductor wafers.

  18. Ground Water Atlas of the United States: Introduction and National Summary

    USGS Publications Warehouse

    Miller, James A.

    1999-01-01

    The Ground Water Atlas of the United States provides a summary of the most important information available for each principal aquifer, or rock unit that will yield usable quantities of water to wells, throughout the 50 States, Puerto Rico, and the U.S. Virgin Islands. The Atlas is an outgrowth of the Regional Aquifer-System Analysis (RASA) program of the U.S. Geological Survey (USGS), a program that investigated 24 of the most important aquifers and aquifer systems of the Nation and one in the Caribbean Islands (fig. 1). The objectives of the RASA program were to define the geologic and hydrologic frameworks of each aquifer system, to assess the geochemistry of the water in the system, to characterize the ground-water flow system, and to describe the effects of development on the flow system. Although the RASA studies did not cover the entire Nation, they compiled much of the data needed to make the National assessments of ground-water resources presented in the Ground Water Atlas of the United States. The Atlas, however, describes the location, extent, and geologic and hydrologic characteristics of all the important aquifers in the United States, including those not studied by the RASA program. The Atlas is written so that it can be understood by readers who are not hydrologists. Simple language is used to explain technical terms. The principles that control the presence, movement, and chemical quality of ground water in different climatic, topographic, and geologic settings are clearly illustrated. The Atlas is, therefore, useful as a teaching tool for introductory courses in hydrology or hydrogeology at the college level and as an overview of ground-water conditions for consultants who need information about an individual aquifer. It also serves as an introduction to regional and National ground-water resources for lawmakers, personnel of local, State, or Federal agencies, or anyone who needs to understand ground-water occurrence, movement, and quality. The

  19. Effect of rotating magnetic field on thermocapillary flow stability and the FZ crystal growth on the ground and in space

    NASA Astrophysics Data System (ADS)

    Feonychev, A. I.

    It is well known that numerous experiments on crystal growth by the Bridgman method in space had met with only limited success. Because of this, only floating zone method is promising at present. However, realization of this method demands solution of some problems, in particular reduction of dopant micro- and macrosegregation. Rotating magnetic field is efficient method for control of flow in electrically conducting fluid and transfer processes. Investigation of rotating magnetic field had initiated in RIAME MAI in 1994 /3/. Results of the last investigations had been presented in /4/. Mathematical model of flow generated by rotating magnetic field and computer program were verified by comparison with experiment in area of developed oscillatory flow. Nonlinear analysis of flow stability under combination of thermocapillary convection and secondary flow generated by rotating magnetic field shows that boundary of transition from laminar to oscillatory flow is nonmonotone function in the plane of Marangoni number (Ma) - combined parameter Reω Ha2 (Ha is Hartman number, Reω is dimensionless velocity of magnetic field rotation). These data give additional knowledge of mechanism of onset of oscillations. In this case, there is reason to believe that the cause is Eckman's viscous stresses in rotating fluid on solid end-walls. It was shown that there is a possibility to increase stability of thermocapillary convection and in doing so to remove the main cause of dopant microsegregation. In doing so, if parameters of rotating magnetic field had been incorrectly chosen the dangerous pulsating oscillations are to develop. Radial macrosegregation of dopant can result from correct choosing of parameters of rotating magnetic field. As example, optimization of rotating magnetic field had been carried out for Ge(Ga) under three values of Marangoni number in weightlessness conditions. In the case when rotating magnetic field is used in terrestrial conditions, under combination of

  20. Rotationally resolved S1<-- S0 electronic spectra of fluorene, carbazole, and dibenzofuran: evidence for Herzberg-Teller coupling with the S2 state.

    PubMed

    Yi, John T; Alvarez-Valtierra, Leonardo; Pratt, David W

    2006-06-28

    Rotationally resolved fluorescence excitation spectra of the S1 <-- S0 origin bands and higher vibronic bands of fluorene (FLU), carbazole (CAR), and dibenzofuran (DBF) have been observed and assigned. Analyses of these data show that replacement of the CH2 group in FLU with a NH group in CAR and an O atom in DBF produces only localized changes in structure, in the ground state. But the three molecules exhibit different changes in geometry when they are excited by light. The S1 states of the three molecules also are electronically very different. The S1 <-- S0 transition moments of CAR and DBF are parallel to the C2 symmetry axis whereas the corresponding transition moment in FLU is perpendicular to this axis. Herzberg-Teller coupling involving the S2 state also has been observed in the spectra of higher vibronic bands of CAR and DBF. Possible reasons for these behaviors are discussed.

  1. Rotationally resolved S1<--S0 electronic spectra of fluorene, carbazole, and dibenzofuran: Evidence for Herzberg-Teller coupling with the S2 state

    NASA Astrophysics Data System (ADS)

    Yi, John T.; Alvarez-Valtierra, Leonardo; Pratt, David W.

    2006-06-01

    Rotationally resolved fluorescence excitation spectra of the S1←S0 origin bands and higher vibronic bands of fluorene (FLU), carbazole (CAR), and dibenzofuran (DBF) have been observed and assigned. Analyses of these data show that replacement of the CH2 group in FLU with a NH group in CAR and an O atom in DBF produces only localized changes in structure, in the ground state. But the three molecules exhibit different changes in geometry when they are excited by light. The S1 states of the three molecules also are electronically very different. The S1←S0 transition moments of CAR and DBF are parallel to the C2 symmetry axis whereas the corresponding transition moment in FLU is perpendicular to this axis. Herzberg-Teller coupling involving the S2 state also has been observed in the spectra of higher vibronic bands of CAR and DBF. Possible reasons for these behaviors are discussed.

  2. Hydrogeologic factors that influence ground water movement in the desert southwest United States

    USGS Publications Warehouse

    Chuang, Frank C.; McKee, Edwin H.; Howard, Keith A.

    2003-01-01

    A project to study ground-water and surface-water interactions in the desert southwestern United States was initiated in 2001 by the Tucson, Arizona office of the Water Resources Division, U.S. Geological Survey (USGS). One of the goals of the Southwest Ground-water Resources Project was to develop a regional synthesis that includes the use of available digital geologic data, which is growing rapidly due to the increasing use of Geographic Information Systems (GIS). Included in this report are the digital maps and databases of geologic information that should have a direct impact on the studies of ground-water flow and surface-water interaction. Ground-water flow is governed by many geologic factors or elements including rock and soil permeability, stratigraphy and structural features. These elements directly influence ground-water flow, which is key to understanding the possible inter-connectivity of aquifer systems in desert basins of the southwestern United States. We derive these elements from the evaluation of regional geology and localized studies of hydrogeologic basins. These elements can then be applied to other unstudied areas throughout the desert southwest. This report presents a regional perspective of the geologic elements controlling ground-water systems in the desert southwest that may eventually lead to greater focus on smaller sub-regions and ultimately, to individual ground-water basins.

  3. Arsenic in ground water of the United States: occurrence and geochemistry

    USGS Publications Warehouse

    Welch, Alan H.; Westjohn, D.B.; Helsel, Dennis R.; Wanty, Richard B.

    2000-01-01

    Concentrations of naturally occurring arsenic in ground water vary regionally due to a combination of climate and geology. Although slightly less than half of 30,000 arsenic analyses of ground water in the United States were 1 μg/L, about 10% exceeded 10 μg/L. At a broad regional scale, arsenic concentrations exceeding 10 μg/L appear to be more frequently observed in the western United States than in the eastern half. Arsenic concentrations in ground water of the Appalachian Highlands and the Atlantic Plain generally are very low ( 1 μg/L). Concentrations are somewhat greater in the Interior Plains and the Rocky Mountain System. Investigations of ground water in New England, Michigan, Minnesota, South Dakota, Oklahoma, and Wisconsin within the last decade suggest that arsenic concentrations exceeding 10 μg/L are more widespread and common than previously recognized.Arsenic release from iron oxide appears to be the most common cause of widespread arsenic concentrations exceeding 10 μg/L in ground water. This can occur in response to different geochemical conditions, including release of arsenic to ground water through reaction of iron oxide with either natural or anthropogenic (i.e., petroleum products) organic carbon. Iron oxide also can release arsenic to alkaline ground water, such as that found in some felsic volcanic rocks and alkaline aquifers of the western United States. Sulfide minerals are both a source and sink for arsenic. Geothermal water and high evaporation rates also are associated with arsenic concentrations 10g/L in ground and surface water, particularly in the west.Arsenic release from iron oxide appears to be the most common cause of widespread arsenic concentrations exceeding 10 µg/L a ground water. This can occur in response to different geochemical conditions, including release of arsenic to ground water through reaction of iron oxide with either natural or anthropogenic (i.e., petroleum products) organic carbon. Iron oxide also can

  4. Submillimeter-wave rotational spectra of DNC in highly excited vibrational states observed in an extended negative glow discharge

    NASA Astrophysics Data System (ADS)

    Amano, T.

    2011-05-01

    Rotational transitions of DNC have been observed in the submillimeter-wave region in an extended negative glow discharge in a gas mixture of CD 4 and N 2. The dissociative recombination reaction of DCND + with electrons is thought to be a dominant channel to produce DNC in highly excited vibrational states. The vibrational temperature for the ν3 vibrational mode is found to be about 4000 K, and the rotational lines in levels up to (0 0 8) are observed. The rotational and centrifugal distortion constants are determined for these states along with those for the (1 0 0) state. The measurement accuracy is high enough to determine some higher order vibration-rotation interaction constants.

  5. Intercept-resend attack on six-state quantum key distribution over collective-rotation noise channels

    NASA Astrophysics Data System (ADS)

    Kevin, Garapo; Mhlambululi, Mafu; Francesco, Petruccione

    2016-07-01

    We investigate the effect of collective-rotation noise on the security of the six-state quantum key distribution. We study the case where the eavesdropper, Eve, performs an intercept-resend attack on the quantum communication between Alice, the sender, and Bob, the receiver. We first derive the collective-rotation noise model for the six-state protocol and then parameterize the mutual information between Alice and Eve. We then derive quantum bit error rate for three intercept-resend attack scenarios. We observe that the six-state protocol is robust against intercept-resend attacks on collective rotation noise channels when the rotation angle is kept within certain bounds. Project supported by the South African Research Chair Initiative of the Department of Science and Technology and National Research Foundation.

  6. The ground state of embryonic stem cell self-renewal

    PubMed Central

    Ying, Qi-Long; Wray, Jason; Nichols, Jennifer; Batlle-Morera, Laura; Doble, Bradley; Woodgett, James; Cohen, Philip; Smith, Austin

    2016-01-01

    In the three decades since pluripotent mouse embryonic stem (ES) cells were first described1,2 they have been derived and maintained by using various empirical combinations of feeder cells, conditioned media, cytokines, growth factors, hormones, fetal calf serum, and serum extracts1–7. Consequently ES-cell self-renewal is generally considered to be dependent on multifactorial stimulation of dedicated transcriptional circuitries, pre-eminent among which is the activation of STAT3 by cytokines (ref. 8). Here we show, however, that extrinsic stimuli are dispensable for the derivation, propagation and pluripotency of ES cells. Self-renewal is enabled by the elimination of differentiation-inducing signalling from mitogen-activated protein kinase. Additional inhibition of glycogen synthase kinase 3 consolidates biosynthetic capacity and suppresses residual differentiation. Complete bypass of cytokine signalling is confirmed by isolating ES cells genetically devoid of STAT3. These findings reveal that ES cells have an innate programme for self-replication that does not require extrinsic instruction. This property may account for their latent tumorigenicity. The delineation of minimal requirements for self-renewal now provides a defined platform for the precise description and dissection of the pluripotent state. PMID:18497825

  7. Effects of Rotational State Excitations on the Dissociative Adsorption Dynamics of D2/Cu(111)

    NASA Astrophysics Data System (ADS)

    Diño, Wilson; Kasai, Hideaki; Okiji, Ayao

    1995-07-01

    Recent time-of-flight experiments show a non-monotonous dependence of the dissociative adsorption/sticking* probability of D2(H2)/Cu(111) on the initial rotational state. There is an observed decrease in the sticking probability with a slight increase in the initial rotational state quantum number j. As j is increased further, the sticking probability eventually increases. We show that, to account for this interesting behaviour, there are two opposing factors working for and against the adsorption process: STEERING EFFECT and ENERGY TRANSFER EFFECT. The first is dueto a dynamical reorientation of the molecule, and the latter is due to the coupling of therotational motion to the translational motion along the reaction path. To illustrate these two effects, we performed quantum mechanical model calculations using a variation of the coupled-channel method, a physically realistic model potential based on available potential energy (hyper-) surface plots for D2(H2)/Cu for two different orientations-parallel and perpendicular to the surface, and the concept of a reaction path.

  8. Formation of Triplet Positron-helium Bound State by Stripping of Positronium Atoms in Collision with Ground State Helium

    NASA Technical Reports Server (NTRS)

    Drachman, Richard J.

    2006-01-01

    Formation of triplet positron-helium bound state by stripping of positronium atoms in collision with ground state helium JOSEPH DI RlENZI, College of Notre Dame of Maryland, RICHARD J. DRACHMAN, NASA/Goddard Space Flight Center - The system consisting of a positron and a helium atom in the triplet state e(+)He(S-3)(sup e) was conjectured long ago to be stable [1]. Its stability has recently been established rigorously [2], and the values of the energies of dissociation into the ground states of Ps and He(+) have also been reported [3] and [4]. We have evaluated the cross-section for this system formed by radiative attachment of a positron in triplet He state and found it to be small [5]. The mechanism of production suggested here should result in a larger cross-section (of atomic size) which we are determining using the Born approximation with simplified initial and final wave functions.

  9. Rotational state selection and orientation of diatomic and asymmetric top molecules via the electric hexapole technique

    NASA Astrophysics Data System (ADS)

    Hain, Toby Douglas

    2000-11-01

    The hexapole rotational state selection of 2∏ Ω diatomic and asymmetric top molecules is investigated. Classical molecular trajectory simulations are shown to reproduce experimental focusing spectra in these large classes of molecules. Deviations from linear Stark effects introduce significant effects in the focusing behavior of both the 2∏ and asymmetric rotor species. The laboratory frame distributions of orientations of the state-selected molecules are quantified by quantum mechanical orientational probability distribution functions (opdf's). Chapter 1 introduces preliminary data for the hexapole focusing of hydroxyl radicals and shows the deviation of the structured focusing curves from the first-order Stark effect. In Chapter 2, the focusing theory is developed for 2∏ diatomics, and the focusing spectra presented in Chapter 1 are analyzed using the theory. The Λ-doublet splitting is found to be the important parameter for simulating the measured focusing spectra. The high field limit opdf's are calculated, and highly anisotropic orientational distributions for the selected states are shown. Chapter 3 shows the laboratory orientation of 2∏ molecules is tunable via the electric field strength of an orienting field for post- hexapole selected rotational states. A laser induced fluorescence experiment is detailed allowing experimental validation of the theoretical opdf's. Chapter 4 explores the scattering of hexapole selected OD rotational states with various target gases. Elastic scattering cross sections are reported for OD + M (M = He, Ar, H2O, CO2, NH3, and CH3F). Hexapole focusing and the subsequent orientation of asymmetric rotors are the subjects of Chapter 5. Matrix treatments are used to calculate the field-free and Stark energies exactly. Perturbation and intermediate Stark effect approximations are compared to the exact matrix method, yielding several general rules useful in analyzing and predicting experimental focusing spectra. The theory

  10. Stationary State After a Quench to the Lieb-Liniger from Rotating BECs

    NASA Astrophysics Data System (ADS)

    Bucciantini, Leda

    2016-08-01

    We study long-time dynamics of a bosonic system after suddenly switching on repulsive delta-like interactions. As initial states, we consider two experimentally relevant configurations: a rotating BEC and two counter-propagating BECs with opposite momentum, both on a ring. In the first case, the rapidity distribution function for the stationary state is derived analytically and it is given by the distribution obtained for the same quench starting from a BEC, shifted by the momentum of each boson. In the second case, the rapidity distribution function is obtained numerically for generic values of repulsive interaction and initial momentum. The significant differences for the case of large versus small quenches are discussed.

  11. Cryo-EM structures of the autoinhibited E. coli ATP synthase in three rotational states.

    PubMed

    Sobti, Meghna; Smits, Callum; Wong, Andrew Sw; Ishmukhametov, Robert; Stock, Daniela; Sandin, Sara; Stewart, Alastair G

    2016-12-21

    A molecular model that provides a framework for interpreting the wealth of functional information obtained on the E. coli F-ATP synthase has been generated using cryo-electron microscopy. Three different states that relate to rotation of the enzyme were observed, with the central stalk's ε subunit in an extended autoinhibitory conformation in all three states. The Fo motor comprises of seven transmembrane helices and a decameric c-ring and invaginations on either side of the membrane indicate the entry and exit channels for protons. The proton translocating subunit contains near parallel helices inclined by ~30° to the membrane, a feature now synonymous with rotary ATPases. For the first time in this rotary ATPase subtype, the peripheral stalk is resolved over its entire length of the complex, revealing the F1 attachment points and a coiled-coil that bifurcates toward the membrane with its helices separating to embrace subunit a from two sides.

  12. Measurement-Induced State Transitions in a Superconducting Qubit: Beyond the Rotating Wave Approximation

    NASA Astrophysics Data System (ADS)

    Sank, Daniel; Chen, Zijun; Khezri, Mostafa; Kelly, J.; Barends, R.; Campbell, B.; Chen, Y.; Chiaro, B.; Dunsworth, A.; Fowler, A.; Jeffrey, E.; Lucero, E.; Megrant, A.; Mutus, J.; Neeley, M.; Neill, C.; O'Malley, P. J. J.; Quintana, C.; Roushan, P.; Vainsencher, A.; White, T.; Wenner, J.; Korotkov, Alexander N.; Martinis, John M.

    2016-11-01

    Many superconducting qubit systems use the dispersive interaction between the qubit and a coupled harmonic resonator to perform quantum state measurement. Previous works have found that such measurements can induce state transitions in the qubit if the number of photons in the resonator is too high. We investigate these transitions and find that they can push the qubit out of the two-level subspace, and that they show resonant behavior as a function of photon number. We develop a theory for these observations based on level crossings within the Jaynes-Cummings ladder, with transitions mediated by terms in the Hamiltonian that are typically ignored by the rotating wave approximation. We find that the most important of these terms comes from an unexpected broken symmetry in the qubit potential. We confirm the theory by measuring the photon occupation of the resonator when transitions occur while varying the detuning between the qubit and resonator.

  13. Recoil-Induced-Resonances in Nonlinear, Ground-State, Pump-Probe Spectroscopy

    DTIC Science & Technology

    2007-11-02

    spectrum by controlling the ratio of the Rabi frequencies of the two fields that comprise the two- photon pump field. Interference in a dressed state ...examine this question. In addition, we show that the interference persists even if the pump fields are in quantized, Fock states . The probe absorption...spectroscopy is developed in which optical fields drive two- photon Raman transitions between ground states of an ensemble of three-level atoms. Effects

  14. Fission of rotating fermium isotopes

    NASA Astrophysics Data System (ADS)

    Baran, A.; Staszczak, A.

    2014-05-01

    In this paper we discuss the process of fission of even fermium isotopes, on the basis of their rotational states. The nuclear intrinsic vorticity and its coupling to the global rotation of the nucleus are used to simulate the interaction between the rotational motion and the pairing field, and lead to pairing quenching in the case of higher angular momentum states. The rotation leads to a decreasing of the fission barrier heights. The ingredients of the model—ground state fission barriers, pairing correlation energies and the cranking moments of inertia—are obtained within the self-consistent Hartree-Fock-Bogoliubov framework using the Skyrme \\text{Sk}{{\\text{M}}^{*}} energy density functional. Fission barriers and half-lives are estimated for spins I up to I = 16ℏ.

  15. Evidence for a gapped spin-liquid ground state in a kagome Heisenberg antiferromagnet

    DOE PAGES

    Fu, Mingxuan; Imai, Takahashi; Han, Tian -Heng; ...

    2015-11-06

    Here, the kagome Heisenberg antiferromagnet is a leading candidate in the search for a spin system with a quantum spin-liquid ground state. The nature of its ground state remains a matter of active debate. We conducted oxygen-17 single-crystal nuclear magnetic resonance (NMR) measurements of the spin-1/2 kagome lattice in herbertsmithite [ZnCu3(OH)6Cl2], which is known to exhibit a spinon continuum in the spin excitation spectrum. We demonstrated that the intrinsic local spin susceptibility χkagome, deduced from the oxygen-17 NMR frequency shift, asymptotes to zero below temperatures of 0.03J, where J ~ 200 kelvin is the copper-copper superexchange interaction. Combined with themore » magnetic field dependence of χkagome that we observed at low temperatures, these results imply that the kagome Heisenberg antiferromagnet has a spin-liquid ground state with a finite gap.« less

  16. Ground State Properties of the 1/2 Flux Harper Hamiltonian

    NASA Astrophysics Data System (ADS)

    Kennedy, Colin; Burton, William Cody; Chung, Woo Chang; Ketterle, Wolfgang

    2015-05-01

    The Harper Hamiltonian describes the motion of charged particles in an applied magnetic field - the spectrum of which exhibits the famed Hofstadter's butterfly. Recent advances in driven optical lattices have made great strides in simulating nontrivial Hamiltonians, such as the Harper model, in the time-averaged sense. We report on the realization of the ground state of bosons in the Harper Hamiltonian for 1/2 flux per plaquette utilizing a tilted two-dimensional lattice with laser assisted tunneling. We detail progress in studying various ground state properties of the 1/2 flux Harper Hamiltonian including ground state degeneracies, gauge-dependent observables, effects of micromotion, adiabatic loading schemes, and emergence and decay of coherence. Additionally, we describe prospects for flux rectification using a period-tripled superlattice and generalizations to three dimensions. MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, Department of Physics, Massachusetts Institute of Technology.

  17. Relativistic Quark-Model Results for Baryon Ground and Resonant States

    SciTech Connect

    Plessas, W.; Melde, T.

    2008-10-13

    Latest results from a study of baryon ground and resonant states within relativistic constituent quark models are reported. After recalling some typical spectral properties, the description of ground states, especially with regard to the nucleon and hyperon electromagnetic structures, is addressed. In the following, recent covariant predictions for pion, eta, and kaon partial decay widths of light and strange baryon resonances below 2 GeV are summarized. These results exhibit a characteristic pattern that is distinct from nonrelativistic or relativized decay studies performed so far. Together with a detailed analysis of the spin, flavor, and spatial structures of the wave functions, it supports a new and extended classification scheme of baryon ground and resonant states into SU(3) flavor multiplets.

  18. Evidence for a gapped spin-liquid ground state in a kagome Heisenberg antiferromagnet.

    PubMed

    Fu, Mingxuan; Imai, Takashi; Han, Tian-Heng; Lee, Young S

    2015-11-06

    The kagome Heisenberg antiferromagnet is a leading candidate in the search for a spin system with a quantum spin-liquid ground state. The nature of its ground state remains a matter of active debate. We conducted oxygen-17 single-crystal nuclear magnetic resonance (NMR) measurements of the spin-1/2 kagome lattice in herbertsmithite [ZnCu3(OH)6Cl2], which is known to exhibit a spinon continuum in the spin excitation spectrum. We demonstrated that the intrinsic local spin susceptibility χ(kagome), deduced from the oxygen-17 NMR frequency shift, asymptotes to zero below temperatures of 0.03J, where J ~ 200 kelvin is the copper-copper superexchange interaction. Combined with the magnetic field dependence of χ(kagome) that we observed at low temperatures, these results imply that the kagome Heisenberg antiferromagnet has a spin-liquid ground state with a finite gap.

  19. Cold collisions of ground-state calcium atoms in a laser field: A theoretical study

    SciTech Connect

    Bussery-Honvault, Beatrice; Launay, Jean-Michel; Moszynski, Robert

    2003-09-01

    State-of-the-art ab initio techniques have been applied to compute the potential-energy curves for the ground X {sup 1}{sigma}{sub g}{sup +} and excited {sup 1}{pi}{sub g}(4s3d) states of the calcium dimer in the Born-Oppenheimer approximation. The weakly bound ground state was calculated by symmetry-adapted perturbation theory, while the strongly bound excited state was computed using a combination of the linear-response theory within the coupled-cluster singles and doubles framework for the core-valence electronic correlation and of the full configuration interaction for the valence-valence correlation. The ground-state potential has been corrected by considering the relativistic terms resulting from the first-order many-electron Breit theory, and the retardation corrections. The magnetic electronic transition dipole moment governing the {sup 1}{pi}{sub g}(leftarrow){sup 1}{sigma}{sub g}{sup +} transitions has been obtained as the first residue of the polarization propagator computed with the coupled-cluster method restricted to single and double excitations. The computed energies and transition moments have been analytically fitted and used in the dynamical calculations of the rovibrational energy levels, ground-state scattering length, photoassociation intensities at ultralow temperatures, and spontaneous emission coefficients from the {sup 1}{pi}{sub g}(4s3d) to the X {sup 1}{sigma}{sub g}{sup +} state. The spectroscopic constants of the theoretical ground-state potential are in a good agreement with the experimental values derived from the Fourier-transform spectra [O. Allard et al., Eur. Phys. J. D (to be published)]. The theoretical s-wave scattering length for the ground state is a=44 bohrs, suggesting that it should be possible to obtain a stable Bose-Einstein condensate of calcium atoms. Finally, the computed photoassociation intensities and spontaneous emission coefficients suggest that it should be possible to obtain cold calcium molecules by

  20. Is rotating between static and dynamic work beneficial for our fatigue state?

    PubMed

    Luger, Tessy; Bosch, Tim; Hoozemans, Marco J M; Veeger, DirkJan H E J; de Looze, Michiel P

    2016-06-01

    Shoulder disorders comprise a large part of work-related musculoskeletal disorders. Risk factors, such as repetitiveness and monotony, may cause muscle fatigue and be attenuated by task rotation. We investigated rotation between a dynamic box-lifting task and a relatively static pick-and-place task and aimed to determine whether (1) a high rotation frequency leads to less fatigue development than a low rotation frequency, and (2) a self-selected rotation frequency leads to less fatigue development than imposed rotation frequencies. Ten participants performed four one-hour rotation schedules: two low frequency rotation schedules rotating at 30min, one high frequency rotation schedule rotating every sixth minute, and a self-selected rotation schedule. Borg, SOFI and electromyography of Trapezius and Deltoid subparts served as fatigue indicators. We found significant signs of fatigue for most schedules regarding the Borg and SOFI ratings and the M. Trapezius pars Descendens. Task rotation frequency had no significant effect on any of the outcome parameters, whereas the self-selected rotation schedule clearly resulted in less development of perceived fatigue than imposed schedules. In conclusion, we think that freedom of rotation has the greatest potential to attenuate potential development of musculoskeletal disorders and we require due caution with the use and interpretation of EMG indicators of fatigue.

  1. On the Ground-State Energy and Local Pressure of an Inhomogeneous Bose Gas

    NASA Astrophysics Data System (ADS)

    Bobrov, V. B.; Trigger, S. A.

    2017-01-01

    The exact expression for the average kinetic energy of an inhomogeneous Bose gas in the ground state is obtained as a functional of the inhomogeneous density of the Bose-Einstein condensate. The result is based on existence of the off-diagonal long-range order in the single-particle density matrix for systems with a Bose-Einstein condensate. This makes it possible to avoid the use of anomalous averages. On this basis, the explicit expressions for the ground-state energy and the local pressure of an inhomogeneous Bose gas are derived within the self-consistent Hartree-Fock approximation.

  2. Model valence-fluctuation systems: variational ground states and magnetic responses

    SciTech Connect

    Brandow, B.H.

    1980-04-01

    Variational ground-state wavefunctions are presented and optimized for two model valence-fluctuation systems, based on Anderson lattice Hamiltonians in the U ..-->.. infinity limit. Although these wavefunctions are approximate, they are treated in an essentially exact manner. The )f/sup 0/, f/sup 1/; n = 1) system has an intuitively reasonable ground-state susceptibility, while the )f/sup 1/, f/sup 2/; n = 2) system is found to exhibit an insulating gap. Due to their different crystal symmetries, this gap should be realized in SmB/sub 6/ but not in SmS.

  3. Detecting ground-state degeneracy in many-body systems through qubit decoherence

    NASA Astrophysics Data System (ADS)

    Cui, Hai-Tao; Yi, Xue-Xi

    2017-02-01

    By coupling with a qubit, we demonstrate that qubit decoherence can unambiguously detect the occurrence of ground-state degeneracy in many-body systems. We first demonstrate universality using the two-band model. Consequently, several exemplifications, focused on topological condensed matter systems in one, two, and three dimensions, are presented to validate our proposal. The key point is that qubit decoherence varies significantly when energy bands touch each other at the Fermi surface. In addition, it can partially reflect the degeneracy inside the band. This feature implies that qubit decoherence can be used for reliable diagnosis of ground-state degeneracy.

  4. Ground state atomic oxygen in high-power impulse magnetron sputtering: a quantitative study

    NASA Astrophysics Data System (ADS)

    Britun, Nikolay; Belosludtsev, Alexandr; Silva, Tiago; Snyders, Rony

    2017-02-01

    The ground state density of oxygen atoms in reactive high-power impulse magnetron sputtering discharges has been studied quantitatively. Both time-resolved and space-resolved measurements were conducted. The measurements were performed using two-photon absorption laser-induced fluorescence (TALIF), and calibrated by optical emission actinometry with multiple Ar emission lines. The results clarify the dynamics of the O ground state atoms in the discharge afterglow significantly, including their propagation and fast decay after the plasma pulse, as well as the influence of gas pressure, O2 admixture, etc.

  5. Ground-state properties of third-row elements with nonlocal density functionals

    SciTech Connect

    Bagno, P.; Jepsen, O.; Gunnarsson, O.

    1989-07-15

    The cohesive energy, the lattice parameter, and the bulk modulus of third-row elements are calculated using the Langreth-Mehl-Hu (LMH), the Perdew-Wang (PW), and the gradient expansion functionals. The PW functional is found to give somewhat better results than the LMH functional and both are found to typically remove half the errors in the local-spin-density (LSD) approximation, while the gradient expansion gives worse results than the local-density approximation. For Fe both the LMH and PW functionals correctly predict a ferromagnetic bcc ground state, while the LSD approximation and the gradient expansion predict a nonmagnetic fcc ground state.

  6. Ground state cooling of a nanomechanical resonator in the nonresolved regime via quantum interference.

    PubMed

    Xia, Keyu; Evers, Jörg

    2009-11-27

    Ground state cooling of a nanomechanical resonator coupled to a superconducting flux qubit is discussed. By inducing quantum interference to cancel unwanted heating excitations, ground state cooling becomes possible in the nonresolved regime. The qubit is modeled as a three-level system in Lambda configuration, and the driving fluxes are applied such that the qubit absorption spectrum exhibits electromagnetically induced transparency, thereby canceling the unwanted excitations. As our scheme allows the application of strong cooling fields, fast and efficient cooling can be achieved.

  7. Dimerized ground state in the one-dimensional spin-1 boson Hubbard model

    SciTech Connect

    Apaja, Vesa; Syljuaasen, Olav F.

    2006-09-15

    We have investigated the one-dimensional spin-1 boson Hubbard model with antiferromagnetic interactions using quantum Monte Carlo methods. We obtain the shapes of the two lowest Mott lobes and show that the ground state within the lowest Mott lobe is dimerized. The results presented here are relevant for optically trapped antiferromagnetic spin-1 bosons. An experimental signature of the dimerized ground state is modulated Bragg peaks in the noise distribution of the atomic cloud obtained after switching off the trap. These Bragg peaks are located at wave vectors corresponding to half-integer multiples of the reciprocal wave vector of the optical lattice.

  8. On stability of ground states for finite crystals in the Schrödinger-Poisson model

    NASA Astrophysics Data System (ADS)

    Komech, A.; Kopylova, E.

    2017-03-01

    We consider the Schrödinger-Poisson-Newton equations for finite crystals under periodic boundary conditions with one ion per cell of a lattice. The electrons are described by one-particle Schrödinger equation. Our main results are (i) the global dynamics with moving ions and (ii) the orbital stability of periodic ground state under a novel Jellium and Wiener-type conditions on the ion charge density. Under the Jellium condition, both ionic and electronic charge densities for the ground state are uniform.

  9. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    NASA Astrophysics Data System (ADS)

    Borges, L. H. C.; Barone, F. A.

    2016-02-01

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schrödinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector.

  10. Preparing ground States of quantum many-body systems on a quantum computer.

    PubMed

    Poulin, David; Wocjan, Pawel

    2009-04-03

    Preparing the ground state of a system of interacting classical particles is an NP-hard problem. Thus, there is in general no better algorithm to solve this problem than exhaustively going through all N configurations of the system to determine the one with lowest energy, requiring a running time proportional to N. A quantum computer, if it could be built, could solve this problem in time sqrt[N]. Here, we present a powerful extension of this result to the case of interacting quantum particles, demonstrating that a quantum computer can prepare the ground state of a quantum system as efficiently as it does for classical systems.

  11. Simulation of the Hydrogen Ground State in Stochastic Electrodynamics-2: Inclusion of Relativistic Corrections

    NASA Astrophysics Data System (ADS)

    Nieuwenhuizen, Theodorus M.; Liska, Matthew T. P.

    2015-10-01

    In a recent paper the authors studied numerically the hydrogen ground state in stochastic electrodynamics (SED) within the the non-relativistic approximation. In quantum theory the leading non-relativistic corrections to the ground state energy dominate the Lamb shift related to the photon cloud that should cause the quantum-like behaviour of SED. The present work takes these corrections into account in the numerical modelling. It is found that they have little effect; the self-ionisation that occurs without them remains present. It is speculated that the point-charge approximation for the electron is the cause of the failure.

  12. Projected shell model study of ground state bands in 171-175Tm

    NASA Astrophysics Data System (ADS)

    Slathia, B.; Devi, R.; Khosa, S. K.

    2016-10-01

    The ground state bands of thulium isotopes with mass numbers (A), ranging from 171 to 175, have been investigated in the framework of the projected shell model. The theoretical results for the energy levels of ground state bands were found to be in reasonable agreement with the observed values. Predictably, E2 transition probabilities have got predicted vis-a-vis transitions with non-availability of experimental values. The E2 transition probability values have been observed to follow the same trend as seen in 171Tm.

  13. On Asymptotic Stability in Energy Space of Ground States for Nonlinear Schrödinger Equations

    NASA Astrophysics Data System (ADS)

    Cuccagna, Scipio; Mizumachi, Tetsu

    2008-11-01

    We consider nonlinear Schrödinger equations iu_t +Δ u +β (|u|^2)u=0 , text{for} (t,x)in mathbb{R}× mathbb{R}^d, where d ≥ 3 and β is smooth. We prove that symmetric finite energy solutions close to orbitally stable ground states converge to a sum of a ground state and a dispersive wave as t → ∞ assuming the so called the Fermi Golden Rule (FGR) hypothesis. We improve the “sign condition” required in a recent paper by Gang Zhou and I.M.Sigal.

  14. Ground and excited state chemistry of some hydrophilic thiazine dyes for possible photogalvanic applications

    SciTech Connect

    Burton, W.C.

    1982-08-01

    The research was designed to study the ground and excited state properties of hydrophilic analogues of the thiazine dye, thionine. The analogues were prepared by substituting ..beta..-hydroxyethyl or N-methylpiperazine groups onto the thiazine chromophore. Positive charges were introduced into the analogues containing the N-methylpiperazine groups by methylation of the N-methyl nitrogen atom of the piperazine ring. After purification and characterization of the analogues, ground state properties such as water solubility and aggregation were studied. Excited state studies involved determination of triplet state lifetimes (tau), and triplet state rate constants for, self quenching, (k/sub SQ/), ferrous quenching (k/sub Q/), and bromide and iodide (k/sub Br/ and K/sub I/) quenching. Oxidation and decay of the photoproducts, semireduced dyes and leuco dyes, was also studied.

  15. Estimation of ground and excited state dipole moments of Oil Red O by solvatochromic shift methods

    NASA Astrophysics Data System (ADS)

    Sıdır, İsa; Gülseven Sıdır, Yadigar

    2015-01-01

    Absorption and fluorescence spectra of Oil Red O (abbreviated as ORO) are recorded in various solvents with different polarity in the range of 250-900 nm, at room temperature. The solvatochromic shift methods have been used to determine the ground state (μg) and excited state (μe) dipole moments depending on dielectric constant and refractive index functions. It is observed that fluorescence spectra show positive solvatochromism whereas absorption spectra do not indicates sensitive behavior to solvent polarity. Excited state dipole moment is found as higher than those of ground state for all of the used methods and it is attributed to more polar excited state of ORO. Theoretical μg has been determined by quantum chemical calculations using DFT and semi empirical methods. HOMO, LUMO, molecular electrostatic potential (MEP) and solvent accessible surface of ORO are calculated by using DFT-B3LYP method.

  16. Understanding the Yang-Mills ground state: The origin of colour confinement

    NASA Astrophysics Data System (ADS)

    Preparata, Giuliano

    1988-01-01

    The essential magnetic instability of the perturbative ground state of a non-abelian Yang-Mills theory recently discovered, is shown to lead to a family of degenerate states, the Savvidy states, where the Yang-Mills fields undergo an infinite (when the ultraviolet cut-off Λ-->∞M) condensation process. These states build up the real Yang-Mills ground state, in which colour is confined and governed by the effective lagrangian of anisotropic chromodynamics (ACD), proposed by the present author a few years ago. This appears to solve the problem of confinement in QCD. On leave of absence from Dipartimento di Fisica, Università di Bari, I-70126 Bari, Italy.

  17. Estimation of ground and excited state dipole moments of Oil Red O by solvatochromic shift methods.

    PubMed

    Sıdır, İsa; Gülseven Sıdır, Yadigar

    2015-01-25

    Absorption and fluorescence spectra of Oil Red O (abbreviated as ORO) are recorded in various solvents with different polarity in the range of 250-900 nm, at room temperature. The solvatochromic shift methods have been used to determine the ground state (μg) and excited state (μe) dipole moments depending on dielectric constant and refractive index functions. It is observed that fluorescence spectra show positive solvatochromism whereas absorption spectra do not indicates sensitive behavior to solvent polarity. Excited state dipole moment is found as higher than those of ground state for all of the used methods and it is attributed to more polar excited state of ORO. Theoretical μg has been determined by quantum chemical calculations using DFT and semi empirical methods. HOMO, LUMO, molecular electrostatic potential (MEP) and solvent accessible surface of ORO are calculated by using DFT-B3LYP method.

  18. Electron impact ionization of helium from its ground and metastable states

    NASA Astrophysics Data System (ADS)

    Zhang-jin, Chen; Ke-zun, Xu

    1999-05-01

    The triple differential cross sections for the ionization of helium from its ground state 1 1S and metastable states 2 1S and 2 3S in coplanar asymmetric geometry by 150, 250 and 400 eV electrons have been calculated in the BBK model. The present results are compared with the experimental data and/or the other theoretical ones. It has been found that the structures for the metastable states differ markedly from those for the ground state. The collision mechanisms for the new structures appearing in the cross sections for the ionization from metastable states have been analysed. And it has been shown how the intensity of recoil peak changes due to the size of the electron orbital. In addition, the optimal kinematical situations for the cross sections are explored for future experiment.

  19. Developing a state water plan: Ground-water conditions in Utah, spring of 1967

    USGS Publications Warehouse

    Baker, C.H.; Price, Don; Butler, R.G.; Mower, R.W.; Herbert, L.R.; Cordova, R.M.; Bolke, E.L.; Bjorklund, L.J.; Robinson, G.B. Jr.; Sandberg, G.W.

    1967-01-01

    This report is the fourth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series are prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources and are designed to provide data to enable interested parties such as legislators, administrators, and planners to keep abreast of changing ground-water conditions.This report, like the others (see references, p. 89), contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. It also contains supplementary data that are related to ground-water use in some areas. In reports of this series, the inclusion of such supplementary data as graphs showing chemical quality of water and maps showing water-table configuration is intended only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.The report includes individual discussions of the most important areas of ground-water withdrawal in the State for the calendar year 1966. Water-level fluctuations, however, are described for the period spring 1966 to spring 1967. Many of the data used in the report were collected by the Geological Survey in cooperation with the Utah State Engineer.

  20. Developing a state water plan: Ground-water conditions in Utah, spring of 1966

    USGS Publications Warehouse

    Hood, J.W.; Herbert, L.R.; Butler, R.G.; Mower, R.W.; Handy, A.H.; Cordova, R.M.; Feltis, R.D.; Bjorklund, L.J.; Robinson, G.B. Jr.; Sandberg, G.W.

    1966-01-01

    This report is the third in a series of annual reports that describe ground-water conditions in Utah. Reports in this series are prepared cooperatively by the U.S. Geological Survey and the Utah Water and Power Board and are designed to provide data to enable interested parties such as legislators, administrators, and planners to keep abreast of changing ground-water conditions.This report, like the first two (Arnow and others, 1964, 1965), contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. It also contains supplementary data that are related to ground-water use in some individual areas. In reports of this series, the inclusion of such supplementary data as graphs showing chemical quality of water and maps showing water-table slope is intended only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.The report includes individual discussions of the most important areas of ground-water withdrawal in the State for the calendar year 1965. Water-level fluctuations, however, are described for the period spring 1965 through spring 1966. Many of the data used in the report were collected by the Geological Survey in cooperation with the Utah State Engineer.

  1. Ground state spin and excitation energies in half-filled Lieb lattices

    NASA Astrophysics Data System (ADS)

    Ţolea, M.; Niţǎ, M.

    2016-10-01

    We present detailed spectral calculations for small Lieb lattices having up to N =4 number of cells, in the regime of half-filling, an instance of particular relevance for the nanomagnetism of discrete systems such as quantum dot arrays, due to the degenerate levels at midspectrum. While for the Hubbard interaction model—and even number of sites—the ground state spin is given by the Lieb theorem, the inclusion of long-range interaction—or odd number of sites—makes the spin state not known a priori, which justifies our approach. We calculate also the excitation energies, which are of experimental importance, and find significant variation induced by the interaction potential. One obtains insights on the mechanisms involved that impose as ground state the Lieb state with lower spin rather than the Hund one with maximum spin for the degenerate levels, showing this in the first and second orders of the interaction potential for the smaller lattices. The analytical results agree with the numerical ones, which are performed by exact diagonalization calculations or by a combined mean-field and configuration interaction method. While the Lieb state is always lower in energy than the Hund state, for strong long-range interaction, when possible, another minimal spin state is imposed as ground state.

  2. Ground-water indicators state pilot studies for Idaho, Minnesota, and New Jersey: Findings report

    SciTech Connect

    Not Available

    1991-09-30

    The Findings Report describes and presents general findings from the three ground-water indicator State pilot studies the U.S. Environmental Protection Agency conducted in Idaho, Minnesota, and New Jersey to investigate the use of indicators to track progress and trends in the ground-water protection effort. EPA evaluated the following five indicators in these studies: Maximum Contaminant Level (MCL) violations by public drinking water supplies; On-site and off-site contamination at hazardous waste sites; Volatile Organic Compound (VOC) concentrations in ground water (as an indicator of waste site and industrial site activity); Nitrate concentrations in ground water (as an indicator of area-wide sources of contamination); and Extent of pesticide use (as an indicator of area-wide pesticide contamination).

  3. Stability of Steady-State Motion of an Isolated System Consisting of a Rotating Body and Two Pendulums

    NASA Astrophysics Data System (ADS)

    Filimonikhin, G. B.; Filimonikhina, I. I.; Pirogov, V. V.

    2014-07-01

    An isolated mechanical system consisting of a rotating body and two pendulums fit on its longitudinal axis is studied. This system models how pendulum, ball, or fluid (ring) dampers decrease or increase the nutation angle of a spin-stabilized artificial satellite. The conditions of origin, existence, and cessation of the steady-state motion of the system, depending on its parameters, and the stability conditions for the primary motion (the body rotates about the longitudinal axis and the pendulums lie on the same line) and secondary motions (the body does not rotate around the longitudinal axis) are established. The residual nutation angle is estimated

  4. Electron Impact Excitation of Xenon from the Ground State and the Metastable State to the 5p57p Levels

    NASA Astrophysics Data System (ADS)

    Chen, Zhan-Bin; Dong, Chen-Zhong; Xie, Lu-You; Jiang, Jun

    2014-03-01

    Electron impact excitation cross sections from the ground state and the lowest metastable state 5p56s J = 2 to the excited states of the 5p57p configuration of xenon are calculated systematically using the fully relativistic distorted wave method. Special attention is paid to the configuration interaction effects in the wave-function expansion of target states. The results are in good agreement with the recent experimental data by Jung et al. [Phys. Rev. A 80 (2009) 062708] over the measured energy range. These accurate theoretical results can be used in the modeling and diagnosis of plasmas containing xenon.

  5. Polarization memory in the nonpolar magnetic ground state of multiferroic CuFeO2

    NASA Astrophysics Data System (ADS)

    Beilsten-Edmands, J.; Magorrian, S. J.; Foronda, F. R.; Prabhakaran, D.; Radaelli, P. G.; Johnson, R. D.

    2016-10-01

    We investigate polarization memory effects in single-crystal CuFeO2, which has a magnetically induced ferroelectric phase at low temperatures and applied B fields between 7.5 and 13 T. Following electrical poling of the ferroelectric phase, we find that the nonpolar collinear antiferromagnetic ground state at B =0 T retains a strong memory of the polarization magnitude and direction, such that upon reentering the ferroelectric phase a net polarization of comparable magnitude to the initial polarization is recovered in the absence of external bias. This memory effect is very robust: in pulsed-magnetic-field measurements, several pulses into the ferroelectric phase with reverse bias are required to switch the polarization direction, with significant switching only seen after the system is driven out of the ferroelectric phase and ground state either magnetically (by application of B >13 T) or thermally. The memory effect is also largely insensitive to the magnetoelastic domain composition, since no change in the memory effect is observed for a sample driven into a single-domain state by application of stress in the [1 1 ¯0 ] direction. On the basis of Monte Carlo simulations of the ground-state spin configurations, we propose that the memory effect is due to the existence of helical domain walls within the nonpolar collinear antiferromagnetic ground state, which would retain the helicity of the polar phase for certain magnetothermal histories.

  6. A projection gradient method for computing ground state of spin-2 Bose–Einstein condensates

    SciTech Connect

    Wang, Hanquan

    2014-10-01

    In this paper, a projection gradient method is presented for computing ground state of spin-2 Bose–Einstein condensates (BEC). We first propose the general projection gradient method for solving energy functional minimization problem under multiple constraints, in which the energy functional takes real functions as independent variables. We next extend the method to solve a similar problem, where the energy functional now takes complex functions as independent variables. We finally employ the method into finding the ground state of spin-2 BEC. The key of our method is: by constructing continuous gradient flows (CGFs), the ground state of spin-2 BEC can be computed as the steady state solution of such CGFs. We discretized the CGFs by a conservative finite difference method along with a proper way to deal with the nonlinear terms. We show that the numerical discretization is normalization and magnetization conservative and energy diminishing. Numerical results of the ground state and their energy of spin-2 BEC are reported to demonstrate the effectiveness of the numerical method.

  7. Autioionizing states in the photionization of the 3s(2)3p(4) (3)Pe ground state of sulfur

    NASA Technical Reports Server (NTRS)

    Tayal, S. S.

    1988-01-01

    The partial and total photoionization cross sections for the S(3s/2/3p/4/ /3/Pe) ground state are calculated in both the dipole length and velocity forms. The prominent features in the cross sections are the autoionization Rydberg series converging to S+(3s/2/p/3/ /2/D/0/, /2/P/0/) excited-state thresholds. The results are pertinent to the study of sulfur in the plasma of Jupiter's satellite Io.

  8. Magnetic states of MnP: muon-spin rotation studies

    NASA Astrophysics Data System (ADS)

    Khasanov, R.; Amato, A.; Bonfà, P.; Guguchia, Z.; Luetkens, H.; Morenzoni, E.; De Renzi, R.; Zhigadlo, N. D.

    2017-04-01

    Muon-spin rotation data collected at ambient pressure (p) and at p  =  2.42 GPa in MnP were analyzed to check their consistency with various low- and high-pressure magnetic structures reported in the literature. Our analysis confirms that in MnP the low-temperature and low-pressure helimagnetic phase is characterised by an increased value of the average magnetic moment compared to the high-temperature ferromagnetic phase. An elliptical double-helical structure with a propagation vector \\mathbf{Q}=(0,0,0.117) , an a-axis moment elongated by approximately 18% and an additional tilt of the rotation plane towards c-direction by ≃ 4 –8° leads to a good agreement between the theory and the experiment. The analysis of the high-pressure μSR data reveals that the new magnetic order appearing for pressures exceeding 1.5 GPa can not be described by keeping the propagation vector \\mathbf{Q}\\parallel c . Even the extreme case—decoupling the double-helical structure into four individual helices—remains inconsistent with the experiment. It is shown that the high-pressure magnetic phase which is a precursor of superconductivity is an incommensurate helical state with \\mathbf{Q}\\parallel b .

  9. Unconventional superconductors under a rotating magnetic field. I. Density of states and specific heat

    NASA Astrophysics Data System (ADS)

    Vorontsov, A. B.; Vekhter, I.

    2007-06-01

    We develop a fully microscopic theory for the calculations of the angle-dependent properties of unconventional superconductors under a rotated magnetic field. We employ the quasiclassical Eilenberger equations and use a variation of the Brandt-Pesch-Tewordt (BPT) method to obtain a closed-form solution for the Green’s function. The equations are solved self-consistently for quasi-two-dimensional dx2-y2(dxy) superconductors with the field rotated in the basal plane. The solution is used to determine the density of states and the specific heat. We find that applying the field along the gap nodes may result in minima or maxima in the angle-dependent specific heat, depending on the location in the T-H plane. This variation is attributed to the scattering of the quasiparticles on vortices, which depends on both the field and the quasiparticle energy, and is beyond the reach of the semiclassical approximation. We investigate the anisotropy across the T-H phase diagram and compare our results with the experiments on heavy fermion CeCoIn5 .

  10. Rapidly rotating neutron stars in general relativity: Realistic equations of state

    NASA Technical Reports Server (NTRS)

    Cook, Gregory B.; Shapiro, Stuart L.; Teukolsky, Saul A.

    1994-01-01

    We construct equilibrium sequences of rotating neutron stars in general relativity. We compare results for 14 nuclear matter equations of state. We determine a number of important physical parameters for such stars, including the maximum mass and maximum spin rate. The stability of the configurations to quasi-radial perturbations is assessed. We employ a numerical scheme particularly well suited to handle rapid rotation and large departures from spherical symmetry. We provide an extensive tabulation of models for future reference. Two classes of evolutionary sequences of fixed baryon rest mass and entropy are explored: normal sequences, which behave very much like Newtonian sequences, and supramassive sequences, which exist for neutron stars solely because of general relativistic effects. Adiabatic dissipation of energy and angular momentum causes a star to evolve in quasi-stationary fashion along an evolutionary sequence. Supramassive sequences have masses exceeding the maximum mass of a nonrotating neutron star. A supramassive star evolves toward eventual catastrophic collapse to a black hole. Prior to collapse, the star actually spins up as it loses angular momentum, an effect that may provide an observable precursor to gravitational collapse to a black hole.

  11. Rotational state-changing cold collisions of hydroxyl ions with helium

    NASA Astrophysics Data System (ADS)

    Hauser, Daniel; Lee, Seunghyun; Carelli, Fabio; Spieler, Steffen; Lakhmanskaya, Olga; Endres, Eric S.; Kumar, Sunil S.; Gianturco, Franco; Wester, Roland

    2015-06-01

    Cold molecules are important for many applications, from fundamental precision measurements, quantum information processing, quantum-controlled chemistry, to understanding the cold interstellar medium. Molecular ions are known to be cooled efficiently in sympathetic collisions with cold atoms or ions. However, little knowledge is available on the elementary cooling steps, because the determination of quantum state-to-state collision rates at low temperature is very challenging for both experiment and theory. Here we present a method to manipulate molecular quantum states by non-resonant photodetachment. Based on this we provide absolute quantum scattering rate coefficients under full quantum state control for the rotationally inelastic collision of hydroxyl anions with helium. Experiment and quantum scattering theory show excellent agreement without adjustable parameters. Very similar rate coefficients are obtained for two different isotopes, which is linked to several quantum scattering resonances appearing at different energies. The presented method is also applicable to polyatomic systems and will help elucidate non-radiative processes in polyaromatic hydrocarbons and protein chromophores.

  12. Conformational analysis of N-methylformamide in ground S0 and excited S1 and T1 electronic states

    NASA Astrophysics Data System (ADS)

    Tukachev, N. V.; Bataev, V. A.; Godunov, I. A.

    2016-07-01

    For conformers of the N-methylformamide (HCONHCH3) molecule, calculations of equilibrium geometry parameters, harmonic vibration frequencies, energy differences and potential barriers to conformational transitions were performed in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states. In the S0 state, the molecule exists in trans and cis stable conformations (having Cs symmetry). Our calculations show that the electronic excitations T1←S0 and S1←S0 cause changes in the structure of conformers: both HCON and HNCC fragments become pyramidal and rotate around the CN bond. As a result, in each excited electronic state under consideration, there are 12 minima forming six pairs of equivalent conformers separated by relatively small potential barriers. One- and two-dimensional potential energy surface sections corresponding to different intramolecular large-amplitude motions were calculated using the MP2/aug-cc-pVTZ (S0) and CASPT2/cc-pVTZ (S1 and T1) methods. Anharmonic vibrational problems for large-amplitude motions were solved, and the corresponding frequencies were estimated.

  13. Steric asymmetry and lambda-doublet propensities in state-to-state rotationally inelastic scattering of NO(2Π1/2) with He

    NASA Astrophysics Data System (ADS)

    de Lange, Marc J. L.; Stolte, Steven; Taatjes, Craig A.; Kłos, Jacek; Groenenboom, Gerrit C.; van der Avoird, Ad

    2004-12-01

    Relative integrated cross sections are measured for rotationally inelastic scattering of NO(2Π1/2), hexapole selected in the upper Λ-doublet level of the ground rotational state (j=0.5), in collisions with He at a nominal energy of 514 cm-1. Application of a static electric field E in the scattering region, directed parallel or antiparallel to the relative velocity vector v, allows the state-selected NO molecule to be oriented with either the N end or the O end towards the incoming He atom. Laser-induced fluorescence detection of the final state of the NO molecule is used to determine the experimental steric asymmetry, SA≡(σv↑↓E-σv↑↑E)/(σv↑↓E+σv↑↑E), which is equal to within a factor of (-1) to the molecular steric effect, Si→f≡(σHe→NO-σHe→ON)/(σHe→NO+σHe→ON). The dependence of the integral inelastic cross section on the incoming Λ-doublet component is also observed as a function of the final rotational (j'), spin-orbit (Ω'), and Λ-doublet (ɛ') state. The measured steric asymmetries are significantly larger than previously observed for NO-Ar scattering, supporting earlier proposals that the repulsive part of the interaction potential is responsible for the steric asymmetry. In contrast to the case of scattering with Ar, the steric asymmetry of NO-He collisions is not very sensitive to the value of Ω'. However, the Λ-doublet propensities are very different for [Ω=0.5(F1)→Ω'=1.5(F2)] and [Ω=0.5(F1)→Ω'=0.5(F1)] transitions. Spin-orbit manifold conserving collisions exhibit a propensity for parity conservation at low Δj, but spin-orbit manifold changing collisions do not show this propensity. In conjunction with the experiments, state-to-state cross sections for scattering of oriented NO(2Π) molecules with He atoms are predicted from close-coupling calculations on restricted coupled-cluster methods including single, double, and noniterated triple excitations [J. Klos, G. Chalasinski, M. T. Berry, R. Bukowski, and

  14. The ground state of a spin-1 anti-ferromagnetic atomic condensate for Heisenberg limited metrology

    NASA Astrophysics Data System (ADS)

    Wu, Ling-Na; You, Li

    2016-05-01

    The ground state of a spin-1 atomic condensate with anti-ferromagnetic interaction can be applied to quantum metrology approaching the Heisenberg limit. Unlike a ferromagnetic condensate state where individual atomic spins are aligned in the same direction, atoms in an anti-ferromagnetic ground state condensate exist as spin singlet pairs, whose inherent correlation promises metrological precisions beyond the standard quantum limit (SQL) for uncorrelated atoms. The degree of improvement over the SQL is measured by quantum Fisher information (QFI), whose dependence on the ratio of linear Zeeman shift p to spin-dependent atomic interaction c is studied. At a typical value of p = 0 . 4 c corresponding to a magnetic field of 28 . 6 μ G with c = h × 50 Hz (for 23 Na atom condensate in the F = 1 state at a typical density of ~1014cm-3), the scaled QFI can reach ~ 0 . 48 N , which is close to the limits of N for NooN state, or 0 . 5 N for twin-Fock state. We hope our work will stimulate experimental efforts towards reaching the anti-ferromagnetic condensate ground state at extremely low magnetic fields.

  15. Systematic study of α preformation probability of nuclear isomeric and ground states

    NASA Astrophysics Data System (ADS)

    Sun, Xiao-Dong; Wu, Xi-Jun; Zheng, Bo; Xiang, Dong; Guo, Ping; Li, Xiao-Hua

    2017-01-01

    In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states and ground states. The results indicate that during the process of α particle preforming, the low lying nuclear isomeric states are similar to ground states. Meanwhile, in the framework of single nucleon energy level structure, we find that for nuclei with nucleon number below the magic numbers, the α preformation probabilities of high-spin states seem to be larger than low ones. For nuclei with nucleon number above the magic numbers, the α preformation probabilities of isomeric states are larger than those of ground states. Supported by National Natural Science Foundation of China (11205083), Construct Program of Key Discipline in Hunan Province, Research Foundation of Education Bureau of Hunan Province, China (15A159), Natural Science Foundation of Hunan Province, China (2015JJ3103, 2015JJ2123), Innovation Group of Nuclear and Particle Physics in USC, Hunan Provincial Innovation Foundation for Postgraduate (CX2015B398)

  16. Rotationally resolved state-to-state photoionization and photoelectron study of titanium carbide and its cation (TiC/TiC{sup +})

    SciTech Connect

    Luo, Zhihong; Huang, Huang; Chang, Yih-Chung; Zhang, Zheng; Ng, C. Y.; Yin, Qing-Zhu

    2014-10-14

    Titanium carbide and its cation (TiC/TiC{sup +}) have been investigated by the two-color visible (VIS)-ultraviolet (UV) resonance-enhanced photoionization and pulsed field ionization-photoelectron (PFI-PE) methods. Two visible excitation bands for neutral TiC are observed at 16 446 and 16 930 cm{sup −1}. Based on rotational analyses, these bands are assigned as the respective TiC({sup 3}Π{sub 1}) ← TiC(X{sup 3}Σ{sup +}) and TiC({sup 3}Σ{sup +}) ← TiC(X{sup 3}Σ{sup +}) transition bands. This assignment supports that the electronic configuration and term symmetry for the neutral TiC ground state are …7σ{sup 2}8σ{sup 1}9σ{sup 1}3π{sup 4} (X{sup 3}Σ{sup +}). The rotational constant and the corresponding bond distance of TiC(X{sup 3}Σ{sup +}; v″ = 0) are determined to be B{sub 0}″ = 0.6112(10) cm{sup −1} and r{sub 0}″ = 1.695(2) Å, respectively. The rotational analyses of the VIS-UV-PFI-PE spectra for the TiC{sup +}(X; v{sup +} = 0 and 1) vibrational bands show that the electronic configuration and term symmetry for the ionic TiC{sup +} ground state are …7σ{sup 2}8σ{sup 1}3π{sup 4} (X{sup 2}Σ{sup +}) with the v{sup +} = 0 → 1 vibrational spacing of 870.0(8) cm{sup −1} and the rotational constants of B{sub e}{sup +} = 0.6322(28) cm{sup −1}, and α{sub e}{sup +} = 0.0085(28) cm{sup −1}. The latter rotational constants yield the equilibrium bond distance of r{sub e}{sup +} = 1.667(4) Å for TiC{sup +}(X{sup 2}Σ{sup +}). The cleanly rotationally resolved VIS-UV-PFI-PE spectra have also provided a highly precise value of 53 200.2(8) cm{sup −1} [6.5960(1) eV] for the adiabatic ionization energy (IE) of TiC. This IE(TiC) value along with the known IE(Ti) has made possible the determination of the difference between the 0 K bond dissociation energy (D{sub 0}) of TiC{sup +}(X{sup 2}Σ{sup +}) and that of TiC(X{sup 3}Σ{sup +}) to be D{sub 0}(Ti{sup +}−C) − D{sub 0}(Ti−C) = 0.2322(2) eV. Similar to previous experimental

  17. Rayleigh approximation to ground state of the Bose and Coulomb glasses

    DOE PAGES

    Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; ...

    2015-01-16

    Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local energies. This leads to frustration and highly degenerate ground states the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the ground state of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Ourmore » findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.« less

  18. Historical Analysis and Charaterization of Ground Level Ozone for Canada and United State

    NASA Astrophysics Data System (ADS)

    Lin, H.; Li, H.; Auld, H.

    2003-12-01

    Ground-level ozone has long been recognized as an important health and ecosystem-related air quality concern in Canada and the United States. In this work we seek to understand the characteristics of ground level ozone conditions for Canada and United States to support the Ozone Annex under the Canada-U.S. Air Quality Agreement. Our analyses are based upon the data collected by Canadian National Air Pollution Surveillance (NAPS, the NAPS database has also been expanded to include U.S. EPA ground level ozone data) network. Historical ozone data from 1974 to 2002 at a total of 538 stations (253 Canadian stations and 285 U.S. stations) were statistically analyzed using several methodologies including the Canada Wide Standard (CWS). A more detailed analysis including hourly, daily, monthly, seasonally and yearly ozone concentration distributions and trends was undertaken for 54 stations.

  19. Rayleigh approximation to ground state of the Bose and Coulomb glasses

    NASA Astrophysics Data System (ADS)

    Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; Berlyand, L.

    2015-01-01

    Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local energies. This leads to frustration and highly degenerate ground states the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the ground state of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.

  20. Bibliography on ground water in glacial-aquifer systems in the Northeastern United States

    USGS Publications Warehouse

    Wiltshire, Denise A.; Lyford, Forest P.; Cohen, A.J.

    1986-01-01

    The U.S. Geological Survey established the Regional Aquifer-System Analysis (RASA) program to evaluate major interconnected aquifers or groups of aquifers that share similar characteristics within a region. One of the objectives of the Northeastern Glacial RASA is to provide information on the occurrence and quality of ground water in glacial deposits in ten States: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, Ohio, Pennsylvania, and New Jersey. To help meet the objectives of the RASA program, an automated bibliographic data base was developed. The data base contains references to ground-water resources of glacial-aquifer systems in the ten States listed above. This bibliography contains more than 700 ground-water related references that date from 1839 through 1984. The bibliography lists books, journal articles, conference proceedings, government and other technical reports, theses, and maps. Unpublished manuscripts, publications in press, newspaper articles, and book reviews are omitted from the bibliography.

  1. Rayleigh approximation to ground state of the Bose and Coulomb glasses

    SciTech Connect

    Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; Berlyand, L.

    2015-01-16

    Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local energies. This leads to frustration and highly degenerate ground states the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the ground state of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.

  2. A genetic algorithm based determination of the ground and excited (1Lb) state structure and the orientation of the transition dipole moment of benzimidazole.

    PubMed

    Schmitt, Michael; Krügler, Daniel; Böhm, Marcel; Ratzer, Christian; Bednarska, Violetta; Kalkman, Ivo; Meerts, W Leo

    2006-01-14

    The structure of benzimidazole has been determined in the electronic ground and excited states using rotationally resolved electronic spectroscopy. The rovibronic spectra of four isotopomers and subsequently the structure of benzimidazole have been automatically assigned and fitted using a genetic algorithm based fitting strategy. The lifetimes of the deuterated isotopomers have been shown to depend on the position of deuteration. The angle of the transition dipole moment with the inertial a-axis could be determined to be -30 degrees. Structures and transition dipole moment orientation have been calculated at various levels of theory and were compared to the experimental results.

  3. Conserved prosegment residues stabilize a late-stage folding transition state of pepsin independently of ground states.

    PubMed

    Dee, Derek R; Horimoto, Yasumi; Yada, Rickey Y

    2014-01-01

    The native folding of certain zymogen-derived enzymes is completely dependent upon a prosegment domain to stabilize the folding transition state, thereby catalyzing the folding reaction. Generally little is known about how the prosegment accomplishes this task. It was previously shown that the prosegment catalyzes a late-stage folding transition between a stable misfolded state and the native state of pepsin. In this study, the contributions of specific prosegment residues to catalyzing pepsin folding were investigated by introducing individual Ala substitutions and measuring the effects on the bimolecular folding reaction between the prosegment peptide and pepsin. The effects of mutations on the free energies of the individual misfolded and native ground states and the transition state were compared using measurements of prosegment-pepsin binding and folding kinetics. Five out of the seven prosegment residues examined yielded relatively large kinetic effects and minimal ground state perturbations upon mutation, findings which indicate that these residues form strengthened and/or non-native contacts in the transition state. These five residues are semi- to strictly conserved, while only a non-conserved residue had no kinetic effect. One conserved residue was shown to form native structure in the transition state. These results indicated that the prosegment, which is only 44 residues long, has evolved a high density of contacts that preferentially stabilize the folding transition state over the ground states. It is postulated that the prosegment forms extensive non-native contacts during the process of catalyzing correct inter- and intra-domain contacts during the final stages of folding. These results have implications for understanding the folding of multi-domain proteins and for the evolution of prosegment-catalyzed folding.

  4. Electron-impact excitation and ionization cross sections for ground state and excited helium atoms

    SciTech Connect

    Ralchenko, Yu. Janev, R.K.; Kato, T.; Fursa, D.V.; Bray, I.; Heer, F.J. de

    2008-07-15

    Comprehensive and critically assessed cross sections for the electron-impact excitation and ionization of ground state and excited helium atoms are presented. All states (atomic terms) with n{<=}4 are treated individually, while the states with n{>=}5 are considered degenerate. For the processes involving transitions to and from n{>=}5 levels, suitable cross section scaling relations are presented. For a large number of transitions, from both ground and excited states, convergent close coupling calculations were performed to achieve a high accuracy of the data. The evaluated/recommended cross section data are presented by analytic fit functions, which preserve the correct asymptotic behavior of the cross sections. The cross sections are also displayed in graphical form.

  5. Solvent dependence of ultrafast ground state recovery of the triphenylmethane dyes, brilliant green and malachite green

    NASA Astrophysics Data System (ADS)

    Nagasawa, Yutaka; Ando, Yoshito; Okada, Tadashi

    1999-10-01

    We have studied femtosecond ground state recovery dynamics of the triphenylmethane dyes brilliant green (BG) and malachite green (MG) by pump-probe spectroscopy at the center wavelength of 635 nm with a time resolution of 33 fs. The ultrafast recovery of the ground state bleach was highly nonexponential and depended on the solvent viscosity, although all time constants were shorter than the solvation times obtained from other measurements. We observed a plateau or a rise component in the signal, which indicates an intermediate state. The rise time showed a viscosity dependence, even in the ultrafast time domain. It should be noted that the decay times were always longer for BG than MG, while the rise time did not show a solute dependence. The torsional motion of the amino-substituted phenyl group may be involved in the ultrafast process to the intermediate state, but lack of a solute dependence indicates that only a small conformational change is involved.

  6. Optomechanical sideband cooling of a micromechanical oscillator close to the quantum ground state

    SciTech Connect

    Riviere, R.; Deleglise, S.; Weis, S.; Schliesser, A.; Kippenberg, T. J.; Gavartin, E.; Arcizet, O.

    2011-06-15

    Cooling a mesoscopic mechanical oscillator to its quantum ground state is elementary for the preparation and control of quantum states of mechanical objects. Here, we pre-cool a 70-MHz micromechanical silica oscillator to an occupancy below 200 quanta by thermalizing it with a 600-mK cold {sup 3}He gas. Two-level-system induced damping via structural defect states is shown to be strongly reduced and simultaneously serves as a thermometry method to independently quantify excess heating due to the cooling laser. We demonstrate that dynamical back action optical sideband cooling can reduce the average occupancy to 9{+-}1 quanta, implying that the mechanical oscillator can be found (10{+-}1)% of the time in its quantum ground state.

  7. Topological characterization of fractional quantum Hall ground states from microscopic Hamiltonians.

    PubMed

    Zaletel, Michael P; Mong, Roger S K; Pollmann, Frank

    2013-06-07

    We show how to numerically calculate several quantities that characterize topological order starting from a microscopic fractional quantum Hall Hamiltonian. To find the set of degenerate ground states, we employ the infinite density matrix renormalization group method based on the matrix-product state representation of fractional quantum Hall states on an infinite cylinder. To study localized quasiparticles of a chosen topological charge, we use pairs of degenerate ground states as boundary conditions for the infinite density matrix renormalization group. We then show that the wave function obtained on the infinite cylinder geometry can be adapted to a torus of arbitrary modular parameter, which allows us to explicitly calculate the non-Abelian Berry connection associated with the modular T transformation. As a result, the quantum dimensions, topological spins, quasiparticle charges, chiral central charge, and Hall viscosity of the phase can be obtained using data contained entirely in the entanglement spectrum of an infinite cylinder.

  8. Optically induced rotation of Rayleigh particles by vortex beams with different states of polarization

    NASA Astrophysics Data System (ADS)

    Li, Manman; Yan, Shaohui; Yao, Baoli; Liang, Yansheng; Lei, Ming; Yang, Yanlong

    2016-01-01

    Optical vortex beams carry optical orbital angular momentum (OAM) and can induce an orbital motion of trapped particles in optical trapping. We show that the state of polarization (SOP) of vortex beams will affect the details of this optically induced orbital motion to some extent. Numerical results demonstrate that focusing the vortex beams with circular, radial or azimuthal polarizations can induce a uniform orbital motion on a trapped Rayleigh particle, while in the focal field of the vortex beam with linear polarization the particle experiences a non-uniform orbital motion. Among the formers, the vortex beam with circular polarization induces a maximum optical torque on the particle. Furthermore, by varying the topological charge of the vortex beams, the vortex beam with circular polarization gives rise to an optimum torque superior to those given by the other three vortex beams. These facts suggest that the circularly polarized vortex beam is more suitable for rotating particles.

  9. Measurement of rubidium ground-state hyperfine transition frequency using atomic fountains

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Yuri B.; Szymaniec, Krzysztof; Edris, Soliman

    2015-08-01

    The results of precision measurements of the 87Rb ground-state hyperfine transition frequency, which were conducted at NPL from 2009 to 2013, are reported. The resulting frequency, measured using NPL’s Cs and Rb atomic frequency standards, demonstrates reasonable agreement with the most recent measurements reported by LNE-SYRTE.

  10. Non-periodic discrete Schrödinger equations: ground state solutions

    NASA Astrophysics Data System (ADS)

    Chen, Guanwei; Schechter, Martin

    2016-06-01

    In this paper, we study a class of non-periodic discrete Schrödinger equations with superlinear non-linearities at infinity. Under conditions weaker than those previously assumed, we obtain the existence of ground state solutions, i.e., non-trivial solutions with least possible energy. In addition, an example is given to illustrate our results.

  11. Ground-state properties of small-size nonlinear dynamical lattices.

    PubMed

    Buonsante, P; Kevrekidis, P G; Penna, V; Vezzani, A

    2007-01-01

    We investigate the ground state of a system of interacting particles in small nonlinear lattices with M >or=3 sites, using as a prototypical example the discrete nonlinear Schrödinger equation that has been recently used extensively in the contexts of nonlinear optics of waveguide arrays and Bose-Einstein condensates in optical lattices. We find that, in the presence of attractive interactions, the dynamical scenario relevant to the ground-state and the lowest-energy modes of such few-site nonlinear lattices reveals a variety of nontrivial features that are absent in the large/infinite lattice limits: the single-pulse solution and the uniform solution are found to coexist in a finite range of the lattice intersite coupling where, depending on the latter, one of them represents the ground state; in addition, the single-pulse mode does not even exist beyond a critical parametric threshold. Finally, the onset of the ground-state (modulational) instability appears to be intimately connected with a nonstandard ("double transcritical") type of bifurcation that, to the best of our knowledge, has not been reported previously in other physical systems.

  12. Magnetic ground state of an individual Fe2+ ion in strained semiconductor nanostructure

    PubMed Central

    Smoleński, T.; Kazimierczuk, T.; Kobak, J.; Goryca, M.; Golnik, A.; Kossacki, P.; Pacuski, W.

    2016-01-01

    Single impurities with nonzero spin and multiple ground states offer a degree of freedom that can be utilized to store the quantum information. However, Fe2+ dopant is known for having a single nondegenerate ground state in the bulk host semiconductors and thus is of little use for spintronic applications. Here we show that the well-established picture of Fe2+ spin configuration can be modified by subjecting the Fe2+ ion to high strain, for example, produced by lattice mismatched epitaxial nanostructures. Our analysis reveals that high strain induces qualitative change in the ion energy spectrum and results in nearly doubly degenerate ground state with spin projection Sz=±2. We provide an experimental proof of this concept using a new system: a strained epitaxial quantum dot containing individual Fe2+ ion. Magnetic character of the Fe2+ ground state in a CdSe/ZnSe dot is revealed in photoluminescence experiments by exploiting a coupling between a confined exciton and the single-iron impurity. We also demonstrate that the Fe2+ spin can be oriented by spin-polarized excitons, which opens a possibility of using it as an optically controllable two-level system free of nuclear spin fluctuations. PMID:26818580

  13. Creation of a strongly dipolar gas of ultracold ground-state 23 Na87 Rb molecules

    NASA Astrophysics Data System (ADS)

    Guo, Mingyang; Zhu, Bing; Lu, Bo; Ye, Xin; Wang, Fudong; Wang, Dajun; Vexiau, Romain; Bouloufa-Maafa, Nadia; Quéméner, Goulven; Dulieu, Olivier

    2016-05-01

    We report on successful creation of an ultracold sample of ground-state 23 Na87 Rb molecules with a large effective electric dipole moment. Through a carefully designed two-photon Raman process, we have successfully transferred the magneto-associated Feshbach molecules to the singlet ground state with high efficiency, obtaining up to 8000 23 Na87 Rb molecules with peak number density over 1011 cm-3 in their absolute ground-state level. With an external electric field, we have induced an effective dipole moment over 1 Debye, making 23 Na87 Rb the most dipolar ultracold particle ever achieved. Contrary to the expectation, we observed a rather fast population loss even for 23 Na87 Rb in the absolute ground state with the bi-molecular exchange reaction energetically forbidden. The origin for the short lifetime and possible ways of mitigating it are currently under investigation. Our achievements pave the way toward investigation of ultracold bosonic molecules with strong dipolar interactions. This work is supported by the Hong Kong RGC CUHK404712 and the ANR/RGC Joint Research Scheme ACUHK403/13.

  14. On the ground state energy of the delta-function Fermi gas

    NASA Astrophysics Data System (ADS)

    Tracy, Craig A.; Widom, Harold

    2016-10-01

    The weak coupling asymptotics to order γ of the ground state energy of the delta-function Fermi gas, derived heuristically in the literature, is here made rigorous. Further asymptotics are in principle computable. The analysis applies to the Gaudin integral equation, a method previously used by one of the authors for the asymptotics of large Toeplitz matrices.

  15. Magnetostriction-driven ground-state stabilization in 2H perovskites

    NASA Astrophysics Data System (ADS)

    Porter, D. G.; Senn, M. S.; Khalyavin, D. D.; Cortese, A.; Waterfield-Price, N.; Radaelli, P. G.; Manuel, P.; zur-Loye, H.-C.; Mazzoli, C.; Bombardi, A.

    2016-10-01

    The magnetic ground state of Sr3A RuO6 , with A =(Li ,Na ) , is studied using neutron diffraction, resonant x-ray scattering, and laboratory characterization measurements of high-quality crystals. Combining these results allows us to observe the onset of long-range magnetic order and distinguish the symmetrically allowed magnetic models, identifying in-plane antiferromagnetic moments and a small ferromagnetic component along the c axis. While the existence of magnetic domains masks the particular in-plane direction of the moments, it has been possible to elucidate the ground state using symmetry considerations. We find that due to the lack of local anisotropy, antisymmetric exchange interactions control the magnetic order, first through structural distortions that couple to in-plane antiferromagnetic moments and second through a high-order magnetoelastic coupling that lifts the degeneracy of the in-plane moments. The symmetry considerations used to rationalize the magnetic ground state are very general and will apply to many systems in this family, such as Ca3A RuO6 , with A =(Li ,Na ) , and Ca3LiOsO6 whose magnetic ground states are still not completely understood.

  16. Prevalence and Characterization of Salmonellae in Commercial Ground Beef in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercially produced ground beef samples (n = 4,136) were collected from seven regions of the United States over a 24 month period (July 2005 to June 2007) and analyzed for the presence of Salmonella using methods to examine enumerable levels and total prevalence. All Salmonella isolated were sero...

  17. Complete α6 m Corrections to the Ground State of H2

    NASA Astrophysics Data System (ADS)

    Puchalski, Mariusz; Komasa, Jacek; Czachorowski, Paweł; Pachucki, Krzysztof

    2016-12-01

    We perform the calculation of all relativistic and quantum electrodynamic corrections of the order of α6 m to the ground electronic state of a hydrogen molecule and present improved results for the dissociation and the fundamental transition energies. These results open the window for the high-precision spectroscopy of H2 and related low-energy tests of fundamental interactions.

  18. Ground Based Reflectance Measurements of Arid Rangeland Vegetation Communities of the Southwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1997 a research program began using an Analytical Spectral Device (ASD-FR) spectroradiometer to collect ground based in situ radiance/reflectance measurements from vegetation communities typical of semiarid/arid rangelands of southwestern United States. Measurements were made after the spring (Ap...

  19. Magnetic ground state of an individual Fe2+ ion in strained semiconductor nanostructure

    NASA Astrophysics Data System (ADS)

    Smoleński, T.; Kazimierczuk, T.; Kobak, J.; Goryca, M.; Golnik, A.; Kossacki, P.; Pacuski, W.

    2016-01-01

    Single impurities with nonzero spin and multiple ground states offer a degree of freedom that can be utilized to store the quantum information. However, Fe2+ dopant is known for having a single nondegenerate ground state in the bulk host semiconductors and thus is of little use for spintronic applications. Here we show that the well-established picture of Fe2+ spin configuration can be modified by subjecting the Fe2+ ion to high strain, for example, produced by lattice mismatched epitaxial nanostructures. Our analysis reveals that high strain induces qualitative change in the ion energy spectrum and results in nearly doubly degenerate ground state with spin projection Sz=+/-2. We provide an experimental proof of this concept using a new system: a strained epitaxial quantum dot containing individual Fe2+ ion. Magnetic character of the Fe2+ ground state in a CdSe/ZnSe dot is revealed in photoluminescence experiments by exploiting a coupling between a confined exciton and the single-iron impurity. We also demonstrate that the Fe2+ spin can be oriented by spin-polarized excitons, which opens a possibility of using it as an optically controllable two-level system free of nuclear spin fluctuations.

  20. Magnetostriction-driven ground-state stabilization in 2H perovskites

    SciTech Connect

    Porter, D. G.; Senn, M. S.; Khalyavin, D. D.; Cortese, A.; Waterfield-Price, N.; Radaelli, P. G.; Manuel, P.; zur-Loye, H. -C.; Mazzoli, C.; Bombardi, A.

    2016-10-04

    In this paper, the magnetic ground state of Sr3ARuO6, with A =(Li,Na), is studied using neutron diffraction, resonant x-ray scattering, and laboratory characterization measurements of high-quality crystals. Combining these results allows us to observe the onset of long-range magnetic order and distinguish the symmetrically allowed magnetic models, identifying in-plane antiferromagnetic moments and a small ferromagnetic component along the c axis. While the existence of magnetic domains masks the particular in-plane direction of the moments, it has been possible to elucidate the ground state using symmetry considerations. We find that due to the lack of local anisotropy, antisymmetric exchange interactions control the magnetic order, first through structural distortions that couple to in-plane antiferromagnetic moments and second through a high-order magnetoelastic coupling that lifts the degeneracy of the in-plane moments. Finally, the symmetry considerations used to rationalize the magnetic ground state are very general and will apply to many systems in this family, such as Ca3ARuO6, with A = (Li,Na), and Ca3LiOsO6 whose magnetic ground states are still not completely understood.

  1. Meta-Atom Behavior in Clusters Revealing Large Spin Ground States.

    PubMed

    Hernández Sánchez, Raúl; Betley, Theodore A

    2015-11-04

    The field of single molecule magnetism remains predicated on super- and double exchange mechanisms to engender large spin ground states. An alternative approach to achieving high-spin architectures involves synthesizing weak-field clusters featuring close M-M interactions to produce a single valence orbital manifold. Population of this orbital manifold in accordance with Hund's rules could potentially yield thermally persistent high-spin ground states under which the valence electrons remain coupled. We now demonstrate this effect with a reduced hexanuclear iron cluster that achieves an S = 19/2 (χ(M)T ≈ 53 cm(3) K/mol) ground state that persists to 300 K, representing the largest spin ground state persistent to room temperature reported to date. The reduced cluster displays single molecule magnet behavior manifest in both variable-temperature zero-field (57)Fe Mössbauer and magnetometry with a spin reversal barrier of 42.5(8) cm(-1) and a magnetic blocking temperature of 2.9 K (0.059 K/min).

  2. Distribution of Elevated Nitrate Concentrations in Ground Water in Washington State

    USGS Publications Warehouse

    Frans, Lonna

    2008-01-01

    More than 60 percent of the population of Washington State uses ground water for their drinking and cooking needs. Nitrate concentrations in ground water are elevated in parts of the State as a result of various land-use practices, including fertilizer application, dairy operations and ranching, and septic-system use. Shallow wells generally are more vulnerable to nitrate contamination than deeper wells (Williamson and others, 1998; Ebbert and others, 2000). In order to protect public health, the Washington State Department of Health requires that public water systems regularly measure nitrate in their wells. Public water systems serving more than 25 people collect water samples at least annually; systems serving from 2 to 14 people collect water samples at least every 3 years. Private well owners serving one residence may be required to sample when the well is first drilled, but are unregulated after that. As a result, limited information is available to citizens and public health officials about potential exposure to elevated nitrate concentrations for people whose primary drinking-water sources are private wells. The U.S. Geological Survey and Washington State Department of Health collaborated to examine water-quality data from public water systems and develop models that calculate the probability of detecting elevated nitrate concentrations in ground water. Maps were then developed to estimate ground water vulnerability to nitrate in areas where limited data are available.

  3. Sequences of ground states and classification of frustration in odd-numbered antiferromagnetic rings

    NASA Astrophysics Data System (ADS)

    Florek, Wojciech; Antkowiak, Michał; Kamieniarz, Grzegorz

    2016-12-01

    The sequences of ground states in frustrated antiferromagnetic rings with odd number of local spins characterized by a single bond defect or by arbitrary uniform couplings to an additional spin located at the center are determined. The sequences provide firm constraints on the total ground-state quantum numbers, which are more stringent than those arising from the Lieb-Mattis theorem for bipartite quantum spin systems. Apart from their theoretical importance, they suggest the possibility of tailoring a given class of the molecular nanomagnets with desired ground-state properties by tuning the relevant couplings. In particular, they predict the spin S =1 /2 ground state for the centered rings composed of the half-integer spins with approximately uniform interactions. They confirm the applicability of the recent classification of spin frustration in both types of molecular nanomagnets. The classification is also discussed in the classical limit for the first class of the rings, providing a direct picture of frustration types. The Lieb-Mattis energy-level ordering and an analog of the Landé band, i.e., the energy spectra properties simplifying the characterization of the rings using the bulk magnetic or NMR measurements, are briefly discussed.

  4. Existence of ground state solutions to Dirac equations with vanishing potentials at infinity

    NASA Astrophysics Data System (ADS)

    Figueiredo, Giovany M.; Pimenta, Marcos T. O.

    2017-01-01

    In this work we study the existence of ground-state solutions of Dirac equations with potentials which are allowed to vanish at infinity. The approach is based on minimization of the energy functional over a generalized Nehari set. Some conditions on the potentials are given in order to overcome the lack of compactness.

  5. Magnetostriction-driven ground-state stabilization in 2H perovskites

    DOE PAGES

    Porter, D. G.; Senn, M. S.; Khalyavin, D. D.; ...

    2016-10-04

    In this paper, the magnetic ground state of Sr3ARuO6, with A =(Li,Na), is studied using neutron diffraction, resonant x-ray scattering, and laboratory characterization measurements of high-quality crystals. Combining these results allows us to observe the onset of long-range magnetic order and distinguish the symmetrically allowed magnetic models, identifying in-plane antiferromagnetic moments and a small ferromagnetic component along the c axis. While the existence of magnetic domains masks the particular in-plane direction of the moments, it has been possible to elucidate the ground state using symmetry considerations. We find that due to the lack of local anisotropy, antisymmetric exchange interactions controlmore » the magnetic order, first through structural distortions that couple to in-plane antiferromagnetic moments and second through a high-order magnetoelastic coupling that lifts the degeneracy of the in-plane moments. Finally, the symmetry considerations used to rationalize the magnetic ground state are very general and will apply to many systems in this family, such as Ca3ARuO6, with A = (Li,Na), and Ca3LiOsO6 whose magnetic ground states are still not completely understood.« less

  6. Breaking new ground in the mind: an initial study of mental brittle transformation and mental rigid rotation in science experts.

    PubMed

    Resnick, Ilyse; Shipley, Thomas F

    2013-05-01

    The current study examines the spatial skills employed in different spatial reasoning tasks, by asking how science experts who are practiced in different types of visualizations perform on different spatial tasks. Specifically, the current study examines the varieties of mental transformations. We hypothesize that there may be two broad classes of mental transformations: rigid body mental transformations and non-rigid mental transformations. We focus on the disciplines of geology and organic chemistry because different types of transformations are central to the two disciplines: While geologists and organic chemists may both confront rotation in the practice of their profession, only geologists confront brittle transformations. A new instrument was developed to measure mental brittle transformation (visualizing breaking). Geologists and organic chemists performed similarly on a measure of mental rotation, while geologists outperformed organic chemists on the mental brittle transformation test. The differential pattern of skill on the two tests for the two groups of experts suggests that mental brittle transformation and mental rotation are different spatial skills. The roles of domain general cognitive resources (attentional control, spatial working memory, and perceptual filling in) and strategy in completing mental brittle transformation are discussed. The current study illustrates how ecological and interdisciplinary approaches complement traditional cognitive science to offer a comprehensive approach to understanding the nature of spatial thinking.

  7. The magnetic structure on the ground state of the equilateral triangular spin tube

    NASA Astrophysics Data System (ADS)

    Matsui, Kazuki; Goto, Takayuki; Manaka, Hirotaka; Miura, Yoko

    2016-12-01

    The ground state of the frustrated equilateral triangular spin tube CsCrF4 is still hidden behind a veil though NMR spectrum broaden into 2 T at low temperature. In order to investigate the spin structure in an ordered state by 19F-NMR, we have determined the anisotropic hyperfine coupling tensors for each three fluorine sites in the paramagnetic state. The measurement field was raised up to 10 T to achieve highest resolution. The preliminary analysis using the obtained hyperfine tensors has shown that the archetypal 120°-type structure in ab-plane does not accord with the NMR spectra of ordered state.

  8. Rotational Spectrum of Sarin

    NASA Astrophysics Data System (ADS)

    Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

    2001-05-01

    As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C4H10FO2P) was observed in the rotationally cold (Trot<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1σ), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm-1. Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G** level of theory is consistent with our experimental findings.

  9. Asteroid 2867 Steins. II. Multi-telescope visible observations, shape reconstruction, and rotational state

    NASA Astrophysics Data System (ADS)

    Lamy, P. L.; Kaasalainen, M.; Lowry, S.; Weissman, P.; Barucci, M. A.; Carvano, J.; Choi, Y.-J.; Colas, F.; Faury, G.; Fornasier, S.; Groussin, O.; Hicks, M. D.; Jorda, L.; Kryszczynska, A.; Larson, S.; Toth, I.; Warner, B.

    2008-09-01

    Context: Asteroid 2867 Steins is the first target of the Rosetta space mission with a flyby scheduled in September 2008. Aims: An early physical characterization is needed to optimize the flyby parameters and the science operations, and to maximize the scientific return. The aim of this article is to characterize the shape and rotational state of this asteroid. Methods: We compile a set of 26 visible light curves whose phase angle coverage extends from 7.5° to 41.7°, and perform their simultaneous inversion relying on convex modeling. Results: The full three-dimensional solution for asteroid 2867 Steins is rather spherical with axial ratios a/b=1.17 and a/c=1.25. The rotational state is characterized by a sidereal period of 6.04681 ± 0.00002 h, and the pole direction defined by its ecliptic coordinates λ ≈ 250° and β ≈ - 89° has an uncertainty of about 5°. It is therefore almost exactly perpendicular to the ecliptic plane, and the viewing geometries are thus restricted to only ±20° about Steins' equator. Consequently, the shape model is not strongly constrained, and the polar flattening has an uncertainty of about 10%. Inversion is basically scale-free, and absolute scaling comes from a measurement of its thermal emission with the Spitzer Space Telescope (Lamy et al. 2008, A&A, 487, 1187), yielding overall dimensions of 5.73 ± 0.52, 4.95±0.45, and 4.58 ± 0.41 km.

  10. Two-photon pathway to ultracold ground state molecules of 23Na40K

    NASA Astrophysics Data System (ADS)

    Park, Jee Woo; Will, Sebastian A.; Zwierlein, Martin W.

    2015-07-01

    We report on high-resolution spectroscopy of ultracold fermionic 23Na40K Feshbach molecules, and identify a two-photon pathway to the rovibrational singlet ground state via a resonantly mixed B1Π ˜ c3Σ+intermediate state. Photoassociation in a 23Na-40K atomic mixture and one-photon spectroscopy on 23Na40K Feshbach molecules reveal about 20 vibrational levels of the electronically excited c3Σ+state. Two of these levels are found to be strongly perturbed by nearby B1Π levels via spin-orbit coupling, resulting in additional lines of dominant singlet character in the perturbed complex {{{B}}}1\\Pi | v=4> ˜ {{{c}}}3{Σ }+| v=25> , or of resonantly mixed character in {{{B}}}1\\Pi | v=12> ˜ {{{c}}}3{Σ }+| v=35> . The dominantly singlet level is used to locate the absolute rovibrational singlet ground state {{{X}}}1{Σ }+| v=0,J=0> via Autler-Townes spectroscopy. We demonstrate coherent two-photon coupling via dark state spectroscopy between the predominantly triplet Feshbach molecular state and the singlet ground state. Its binding energy is measured to be 5212.0447(1) cm-1, a thousand-fold improvement in accuracy compared to previous determinations. In their absolute singlet ground state, 23Na40K molecules are chemically stable under binary collisions and possess a large electric dipole moment of 2.72 Debye. Our work thus paves the way towards the creation of strongly dipolar Fermi gases of NaK molecules.

  11. Evolution of the Hox gene complex from an evolutionary ground state.

    PubMed

    Gehring, Walter J; Kloter, Urs; Suga, Hiroshi

    2009-01-01

    In this chapter, we consider the question of how the ordered clusters of Hox genes arose during evolution. Since ordered Hox clusters are found in all major superphyla, we have to assume that the Hox clusters arose before the Cambrian "explosion" giving rise to all of these taxa. Based on his studies of the bithorax complex (BX-C) in Drosophila Lewis considered the ground state to be the mesothoracic segment (T2) since the deletion of all of the genes of the BX-C leads to a transformation of all segments from T3 to A8/9 (the last abdominal segment) into T2 segments. We define the developmental ground state genetically, by assuming that loss-of-function mutants lead to transformations toward the ground state, whereas gain-of-function mutants lead to homeotic transformations away from the ground state. By this definition, T2 also represents the developmental ground state, if one includes the anterior genes, that is, those of the Antennapedia complex. We have reconstructed the evolution of the Hox cluster on the basis of known genetic mechanisms which involve unequal crossover and lead from an urhox gene, first to an anterior and a posterior gene and subsequently to intermediate genes which are progressively inserted, between the anterior and posterior genes. These intermediate genes are recombinant due to unequal crossover, whereas the anterior and posterior genes are not affected and therefore had the longest time to diverge from the urhox gene. The molecular phylogenetic analysis strongly supports this model. We consider the ground state to be both developmental and evolutionary and to represent the prototypic body segment. It corresponds to T2 and is specified by Antennapedia or Hox6, respectively. Experiments in the mouse also suggest that the ground state is a thoracic segment. Evolution leads from the prototypic segment to segmental divergence in both the anterior and posterior direction. The most anterior head and tail segments are specified by homeobox genes

  12. B2N2O4: Prediction of a Magnetic Ground State for a Light Main-Group Molecule

    SciTech Connect

    Varga, Zoltan; Truhlar, Donald G.

    2015-09-08

    Cyclobutanetetrone, (CO)4, has a triplet ground state. Here we predict, based on electronic structure calculations, that the B2N2O4 molecule also has a triplet ground state and is therefore paramagnetic; the structure is an analogue of (CO)4 in which the carbon ring is replaced by a (BN)2 ring. Similar to (CO)4, the triplet ground-state structure of B2N2O4 is also thermodynamically unstable. Besides analysis of the molecular orbitals, we found that the partial atomic charges are good indicators for predicting magnetic ground states.

  13. Using the ground state of an antiferromagnetic spin-1 atomic condensate for Heisenberg-limited metrology

    NASA Astrophysics Data System (ADS)

    Wu, Ling-Na; You, L.

    2016-03-01

    We show that the ground state of a spin-1 atomic condensate with antiferromagnetic interactions constitutes a useful resource for quantum metrology upon approaching the Heisenberg limit. Unlike a ferromagnetic condensate state where individual atomic spins are aligned in the same direction, the antiferromagnetic ground-state condensate is a condensate of spin-singlet atom pairs. The inherent correlation between paired atoms allows for parameter estimation at precisions beyond the standard quantum limit (SQL) for uncorrelated atoms. The degree of improvement over the SQL is measured by the scaled quantum Fisher information (QFI), whose dependence on the ratio of linear Zeeman shift p to spin-dependent atomic interaction c is studied. At a typical value of p =0.4 c , which corresponds to a magnetic field of 28.6 μ G for c =50 h Hz (for 23Na atom condensate in the F =1 state at a typical density of ˜1014cm-3 ), the scaled QFI can reach ˜0.48 N , which approaches the limit of 0.5 N for the twin-Fock state |N/2 > +|N/2 > - . Our work encourages experimental efforts to reach the ground state of an antiferromagnetic condensate at a extremely low magnetic field.

  14. Long-range interactions between polar bialkali ground-state molecules in arbitrary vibrational levels

    SciTech Connect

    Vexiau, R.; Lepers, M. Aymar, M.; Bouloufa-Maafa, N.; Dulieu, O.

    2015-06-07

    We have calculated the isotropic C{sub 6} coefficients characterizing the long-range van der Waals interaction between two identical heteronuclear alkali-metal diatomic molecules in the same arbitrary vibrational level of their ground electronic state X{sup 1}Σ{sup +}. We consider the ten species made up of {sup 7}Li, {sup 23}Na, {sup 39}K, {sup 87}Rb, and {sup 133}Cs. Following our previous work [Lepers et al., Phys. Rev. A 88, 032709 (2013)], we use the sum-over-state formula inherent to the second-order perturbation theory, composed of the contributions from the transitions within the ground state levels, from the transition between ground-state and excited state levels, and from a crossed term. These calculations involve a combination of experimental and quantum-chemical data for potential energy curves and transition dipole moments. We also investigate the case where the two molecules are in different vibrational levels and we show that the Moelwyn-Hughes approximation is valid provided that it is applied for each of the three contributions to the sum-over-state formula. Our results are particularly relevant in the context of inelastic and reactive collisions between ultracold bialkali molecules in deeply bound or in Feshbach levels.

  15. Developing a state water plan: Ground-water conditions in Utah, spring of 1971

    USGS Publications Warehouse

    Cordova, R.M.; Bjorklund, L.J.; McGreevy, L.J.; Bolke, E.L.; Sumison, C.T.; Herbert, L.R.; Butler, R.G.; Mower, R.W.; Sandberg, G.W.; Adams, D.B.

    1971-01-01

    This report is the eighth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series are prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources and are designed to provide data to enable interested parties such as legislators, administrators, and planners to keep abreast of changing ground-water conditions.This report, like the others (see references, p. 21), contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. It also contains supplementary data that are related to ground-water use in some areas. In reports of this series, the inclusion of such supplementary data as graphs showing chemical quality of water and maps showing water-table configuration is intended only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.The report includes individual discussions of the most important areas of ground-water withdrawal in the State for the calendar year 1970. Water-level fluctuations, however, are described for the period spring 1970 to spring 1971. Many of the data used in the report were collected by the Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  16. Developing a state water plan: Ground-water conditions in Utah, spring of 1984

    USGS Publications Warehouse

    Avery, Charles; Herbert, L.R.; Bischoff, Donald A.; Clark, David W.; Seiler, Ralph L.; Guttormson, Kevin; Elizondo, Melanie S.; Jensen, V.L.; Enright, Michael; Emett, D.C.; Burden, Carole B.; Eckenwiler, M.R.; Sandberg, G.W.

    1984-01-01

    This is the twenty-first in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawals from wells, water-level changes, and related changes in precipitation and streamflow. Supplementary data such as graphs showing chemical quality of water and maps showing ground-water level contours are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1983. Water-level fluctuations, however, are described from the spring of 1983 to the spring of 1984. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  17. Developing a state water plan: Ground-water conditions in Utah, spring of 1983

    USGS Publications Warehouse

    Appel, Cynthia L.; Herbert, L.R.; Bischoff, Donald A.; Smith, Melanie E.; Seiler, Ralph L.; Guttormson, Kevin; Jensen, V.L.; Enright, Michael; Emett, D.C.; Burden, Carole B.; Beard, R.C.; Sultz, L.G.; Eckenwiler, M.R.; Sandberg, G.W.

    1983-01-01

    This is the twentieth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawals from wells, water-level changes, and related changes in precipitation and streamflow. Supplementary data such as graphs showing chemical quality of water and maps showing ground-water level contours are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1982. Water-level fluctuations, however, are described for spring 1982 to spring 1983 and spring 1963 to spring 1983. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  18. Developing a state water plan: Ground-water conditions in Utah, spring of 1982

    USGS Publications Warehouse

    Holmes, Walter F.; Herbert, L.R.; Bischoff, D.A.; Smith, Melanie E.; Seiler, R.L.; Steiger, Judy I.; Appel, Cynthia L.; Jensen, V.L.; Enright, Michael; Emett, D.C.; Burden, Carole B.; Beard, R.C.; Sultz, L.G.; Eckenwiler, M.R.; Sandberg, G.W.

    1982-01-01

    This is the nineteenth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawals from wells, water-level changes, and related changes in precipitation and streamflow. Supplementary data such as graphs showing chemical quality of water and maps showing ground-water level contours are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1981. Water-level fluctuations, however, are described for the periiod spring 1981 to spring 1982. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  19. Developing a state water plan: Ground-water conditions in Utah, spring of 1969

    USGS Publications Warehouse

    Baker, C.H.; Bjorklund, L.J.; Bolke, E.L.; Mower, R.W.; Herbert, L.R.; Cordova, R.M.; Butler, R.G.; Sandberg, G.W.

    1969-01-01

    This report is the sixth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series are prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources and are designed to provide data to enable interested parties such as legislators, administrators, and planners to keep abreast of changing ground-water conditions.This report, like the others (see references, p. 12), contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. It also contains supplementary data that are related to ground-water use in some areas. In reports of this series, the inclusion of such supplementary data as graphs showing chemical quality of water and maps showing water-table configuration is intended only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.The report includes individual discussions of the most important areas of ground-water withdrawal in the State for the calendar year 1968. Water-level fluctuations, however, are described for the period spring 1968 to spring 1969. Many of the data used in the report were collected by the Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  20. Developing a state water plan: Ground-water conditions in Utah, spring of 1970

    USGS Publications Warehouse

    Sumison, C.T.; Bjorklund, L.J.; Bolke, E.L.; Mower, R.W.; Herbert, L.R.; Cordova, R.M.; Butler, R.G.; Sandberg, G.W.

    1970-01-01

    This report is the seventh in a series of annual reports that describe ground-water conditions in Utah. Reports in this series are prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources and are designed to provide data to enable interested parties such as legislators, administrators, and planners to keep abreast of changing ground-water conditions.This report, like the others (see references, p. 22), contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. It also contains supplementary data that are related to ground-water use in some areas. In reports of this series, the inclusion of such supplementary data as graphs showing chemical quality of water and maps showing water-table configuration is intended only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.The report includes individual discussions of the most important areas of ground-water withdrawal in the State for the calendar year 1969. Water-level fluctuations, however, are described for the period spring 1969 to spring 1970. Many of the data used in the report were collected by the Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  1. Developing a state water plan: Ground-water conditions in Utah, spring of 1985

    USGS Publications Warehouse

    Seiler, Ralph L.; Herbert, L.R.; Bischoff, Donald A.; Clark, David W.; Pyper, George; Burden, Carole B.; Jensen, V.L.; Enright, Michael; Emett, D.C.; Sether, B.A.; Eckenwiler, M.R.; Sandberg, G.W.

    1985-01-01

    This is the twenty-second in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawals from wells, water-level changes, and related changes in precipitation and streamflow. Supplementary data such as graphs showing chemical quality of water and maps showing ground-water level contours are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1984. Water-level fluctuations, however, are described from the spring of 1984 to the spring of 1985. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

  2. Stress-free states of continuum dislocation fields: Rotations, grain boundaries, and the Nye dislocation density tensor

    NASA Astrophysics Data System (ADS)

    Limkumnerd, Surachate; Sethna, James P.

    2007-06-01

    We derive general relations between grain boundaries, rotational deformations, and stress-free states for the mesoscale continuum Nye dislocation density tensor. Dislocations generally are associated with long-range stress fields. We provide the general form for dislocation density fields whose stress fields vanish. We explain that a grain boundary (a dislocation wall satisfying Frank’s formula) has vanishing stress in the continuum limit. We show that the general stress-free state can be written explicitly as a (perhaps continuous) superposition of flat Frank walls. We show that the stress-free states are also naturally interpreted as configurations generated by a general spatially dependent rotational deformation. Finally, we propose a least-squares definition for the spatially dependent rotation field of a general (stressful) dislocation density field.

  3. Quantum annealing search of Ising spin glass ground state(s) with tunable transverse and longitudinal fields

    NASA Astrophysics Data System (ADS)

    Rajak, A.; Chakrabarti, B. K.

    2014-09-01

    Here we first discuss briefly the quantum annealing technique. We then study the quantum annealing of Sherrington-Kirkpatrick spin glass model with the tuning of both transverse and longitudinal fields. Both the fields are time-dependent and vanish adiabatically at the same time, starting from high values. We solve, for rather small systems, the time-dependent Schrodinger equation of the total Hamiltonian by employing a numerical technique. At the end of annealing we obtain the final state having high overlap with the exact ground state(s) of classical spin glass system (obtained independently).

  4. One-way rotation of a molecule-rotor driven by a shot noise.

    PubMed

    Echeverria, Jorge; Monturet, Serge; Joachim, Christian

    2014-03-07

    The shot noise of a tunneling current passing through a molecule-motor can sustain a one-way rotation when populating the molecular excited states by tunneling inelastic excitations. We demonstrate that a ratchet-like ground state rotation potential energy curve is not necessary for the rotation to occur. A relative shift in energy difference between the maxima of this ground state and the minima of the excited states is the necessary condition to get to a unidirectional rotation. The rotor speed of rotation and its rotation direction are both controlled by this shift, indicating the necessity of a careful design of both the ground and excited states of the next generation of molecule-motors to be able to generate a motive power at the nanoscale.

  5. Thermalization of rotational states of NO A 2Σ+(v = 0) in an atmospheric pressure plasma

    NASA Astrophysics Data System (ADS)

    van Gessel, A. F. H.; Bruggeman, P. J.

    2013-05-01

    Laser induced fluorescence (LIF) measurements of nitric oxide (NO) are performed in an atmospheric pressure microwave plasma jet, operated with a mixture of He and 3% air. The fluorescence signal of NO A 2Σ+(v = 0) is measured time and fluorescence wavelength resolved. Based on the evolution of the rotational spectrum at different positions in the plasma, we determined the thermalization time of the rotational distribution of NO A after pumping a single transition, at temperatures in the range 300-1500 K. Also, a LIF-RET (rotational energy transfer) model is developed to simulate the RET and to calculate the thermalization time. The RET rate coefficients are calculated using the energy corrected sudden-exponential power scaling law. It was found that it is necessary to take the fine structure of the rotational states into account. At room temperature the results of the measurement and the simulation are consistent, and the thermalization occurs during the laser pulse (11 ± 1 ns). At elevated temperatures the measurements show a large increase in thermalization time, up to 35 ± 4 ns at 1474 K. This time is much longer than the laser pulse, and of the order of the NO A lifetime. This means that for spectroscopy measurements of the rotational states of NO A, the RET has to be taken into account to derive gas temperatures from the rotational distribution of NO A.

  6. National and State Attitudes of US Adults Toward Tobacco-Free School Grounds, 2009–2010

    PubMed Central

    Patel, Roshni; Kegler, Michelle C.; Brener, Nancy D.; King, Brian A.

    2015-01-01

    Introduction Schools are an important environment for addressing tobacco use among youth. Tobacco-free school policies can help reduce the social acceptability of tobacco use and prevent tobacco initiation among youth. This study assessed attitudes toward tobacco-free school grounds among US adults. Methods Data came from the 2009–2010 National Adult Tobacco Survey, a telephone survey of adults aged 18 or older in the 50 US states and District of Columbia. Respondents were considered to have a favorable attitude toward tobacco-free school grounds if they reported tobacco use should be completely banned on school grounds, including fields and parking lots, and at all school events. Data were assessed using descriptive statistics and multivariable logistic regression, overall and by tobacco use status. Correlates were sex, age, race/ethnicity, education, marital status, income, sexual orientation, US region, and whether respondent lived with any children aged 17 years or younger. Results Nationally, 86.1% of adults had a favorable attitude toward tobacco-free school grounds, with larger percentages among nontobacco users (91.9%) than current users (76.1%). State prevalence ranged from 80.0% (Kentucky) to 90.9% (Washington). Overall odds of favorable attitudes were higher among nontobacco users (referent, current users), women (referent, men), and adults aged 25 or older (referent, aged 18–24); odds were lower among residents of the South (referent, West) and lesbian, gay, bisexual, or transgender adults (referent, heterosexual or straight). Conclusion Nearly 9 in 10 US adults have a favorable attitude toward tobacco-free school grounds, but attitudes vary across states and subpopulations. Opportunities exist to educate the public about the benefits of tobacco-free school grounds, which might help reduce tobacco use among youth. PMID:26719899

  7. Ground-state kinetics of bistable redox-active donor-acceptor mechanically interlocked molecules.

    PubMed

    Fahrenbach, Albert C; Bruns, Carson J; Li, Hao; Trabolsi, Ali; Coskun, Ali; Stoddart, J Fraser

    2014-02-18

    The ability to design and confer control over the kinetics of theprocesses involved in the mechanisms of artificial molecular machines is at the heart of the challenge to create ones that can carry out useful work on their environment, just as Nature is wont to do. As one of the more promising forerunners of prototypical artificial molecular machines, chemists have developed bistable redox-active donor-acceptor mechanically interlocked molecules (MIMs) over the past couple of decades. These bistable MIMs generally come in the form of [2]rotaxanes, molecular compounds that constitute a ring mechanically interlocked around a dumbbell-shaped component, or [2]catenanes, which are composed of two mechanically interlocked rings. As a result of their interlocked nature, bistable MIMs possess the inherent propensity to express controllable intramolecular, large-amplitude, and reversible motions in response to redox stimuli. In this Account, we rationalize the kinetic behavior in the ground state for a large assortment of these types of bistable MIMs, including both rotaxanes and catenanes. These structures have proven useful in a variety of applications ranging from drug delivery to molecular electronic devices. These bistable donor-acceptor MIMs can switch between two different isomeric states. The favored isomer, known as the ground-state co-conformation (GSCC) is in equilibrium with the less favored metastable state co-conformation (MSCC). The forward (kf) and backward (kb) rate constants associated with this ground-state equilibrium are intimately connected to each other through the ground-state distribution constant, KGS. Knowing the rate constants that govern the kinetics and bring about the equilibration between the MSCC and GSCC, allows researchers to understand the operation of these bistable MIMs in a device setting and apply them toward the construction of artificial molecular machines. The three biggest influences on the ground-state rate constants arise from

  8. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico.

    PubMed

    Villalba, L; Colmenero Sujo, L; Montero Cabrera, M E; Cano Jiménez, A; Rentería Villalobos, M; Delgado Mendoza, C J; Jurado Tenorio, L A; Dávila Rangel, I; Herrera Peraza, E F

    2005-01-01

    This paper reports (222)Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited (222)Rn concentrations exceeding 11Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of (222)Rn found may be entirely attributed to the nature of aquifer rocks.

  9. Rotational Spectrum and Internal Rotation Barrier of 1-Chloro-1,1-difluoroethane

    NASA Astrophysics Data System (ADS)

    Alonso, José L.; López, Juan C.; Blanco, Susana; Guarnieri, Antonio

    1997-03-01

    The rotational spectra of 1-chloro-1,1-difluoroethane (HCFC-142b) has been investigated in the frequency region 8-115 GHz with Stark, waveguide Fourier transform (FTMW), and millimeter-wave spectrometers. Assignments in large frequency regions with the corresponding frequency measurements have been made for the ground andv18= 1 (CH3torsion) vibrational states of the35Cl isotopomer and for the ground state of the37Cl species. Accurate rotational, quartic centrifugal distortion, and quadrupole coupling constants have been determined from global fits considering all these states. SmallA-Einternal rotation splittings have been observed for thev18= 1 vibrational state using FTMW spectroscopy. The barrier height for the internal rotation of the methyl group has been determined to be 3751 (4) cal mol-1, in disagreement with the previous microwave value of 4400 (100) cal mol-1reported by G. Graner and C. Thomas [J. Chem. Phys.49,4160-4167 (1968)].

  10. Centrifugal stretching from lifetime measurements in the 170Hf ground state band

    NASA Astrophysics Data System (ADS)

    Smith, M. K.; Werner, V.; Terry, J. R.; Pietralla, N.; Petkov, P.; Berant, Z.; Casperson, R. J.; Heinz, A.; Henning, G.; Lüttke, R.; Qian, J.; Shoraka, B.; Rainovski, G.; Williams, E.; Winkler, R.

    2013-04-01

    Centrifugal stretching in the deformed rare-earth nucleus 170Hf is investigated using high-precision lifetime measurements, performed with the New Yale Plunger Device at Wright Nuclear Structure Laboratory, Yale University. Excited states were populated in the fusion-evaporation reaction 124Sn(50Ti,4n)170Hf at a beam energy of 195 MeV. Recoil distance doppler shift data were recorded for the ground state band through the J=16+ level. The measured B(E2) values and transition quadrupole moments improve on existing data and show increasing β deformation in the ground state band of 170Hf. The results are compared to descriptions by a rigid rotor and by the confined β-soft rotor model.

  11. Study of ground and excited state decays in N ≈ Z Ag nuclei

    NASA Astrophysics Data System (ADS)

    Moschner, K.; Blazhev, A.; Warr, N.; Boutachkov, P.; Davies, P.; Wadsworth, R.; Ameil, F.; Baba, H.; Bäck, T.; Dewald, M.; Doornenbal, P.; Faestermann, T.; Gengelbach, A.; Gerl, J.; Gernhäuser, R.; Go, S.; Górska, M.; Grawe, H.; Gregor, E.; Hotaka, H.; Isobe, T.; Jenkins, D. G.; Jolie, J.; Jung, H. S.; Kojouharov, I.; Kurz, N.; Lewitowicz, M.; Lorusso, G.; Merchan, E.; Naqvi, F.; Nishibata, H.; Nishimura, D.; Nishimura, S.; Pietralla, N.; Schaffner, H.; Söderström, P.-A.; Steiger, K.; Sumikama, T.; Taprogge, J.; Thöle, P.; Watanabe, H.; Werner, V.; Xu, Z. Y.; Yagi, A.; Yoshinaga, K.; Zhu, Y.

    2015-05-01

    A decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic 100Sn. The N = Z nuclei 98In, 96Cd and 94Ag were of particular interest for the present study. Preliminary results on the neutron deficient nuclei 93Ag and 94Ag are presented. In 94Ag a more precise value for the half-life of the ground state's superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Qβ values from the measured data. The decay of 93Ag is discussed based on the observed implantation-decay correlation events.

  12. Formation of ultracold polar ground state molecules via an optical process

    NASA Astrophysics Data System (ADS)

    Dulieu, Olivier; Borsalino, Dimitri; Orban, Andrea; Vexiau, Romain; Londono-Florez, Beatriz; Crubellier, Anne; Luc, Eliane; Bouloufa-Maafa, Nadia

    2015-05-01

    Based on spectroscopic studies available in the literature completed by accurate ab initio calculations for potentail energy curves, spin-orbit couplings, and transition dipole moments, we investigate several optical coherent schemes to create ultracold bosonic and fermionic ultracold polar molecules in their absolute rovibrational ground level, starting from a weakly bound level of their electronic ground state manifold. The processes rely on the existence of convenient electronically excited states allowing an efficient stimulated Raman adiabatic transfer (STIRAP) of the level population. Illustrations are given for KRb and KCs. A model for the hyperfine structure of the excited molecular states is also presented. Supported by Agence Nationale de la Recherche (ANR), project COPOMOL (# ANR-13-IS04-0004-01).

  13. Ground-State Cooling of a Mechanical Oscillator by Interference in Andreev Reflection

    NASA Astrophysics Data System (ADS)

    Stadler, P.; Belzig, W.; Rastelli, G.

    2016-11-01

    We study the ground-state cooling of a mechanical oscillator linearly coupled to the charge of a quantum dot inserted between a normal metal and a superconducting contact. Such a system can be realized, e.g., by a suspended carbon nanotube quantum dot with a capacitive coupling to a gate contact. Focusing on the subgap transport regime, we analyze the inelastic Andreev reflections which drive the resonator to a nonequilibrium state. For small coupling, we obtain that vibration-assisted reflections can occur through two distinct interference paths. The interference determines the ratio between the rates of absorption and emission of vibrational energy quanta. We show that ground-state cooling of the mechanical oscillator can be achieved for many of the oscillator's modes simultaneously or for single modes selectively, depending on the experimentally tunable coupling to the superconductor.

  14. Ground-State Cooling of a Mechanical Oscillator by Interference in Andreev Reflection.

    PubMed

    Stadler, P; Belzig, W; Rastelli, G

    2016-11-04

    We study the ground-state cooling of a mechanical oscillator linearly coupled to the charge of a quantum dot inserted between a normal metal and a superconducting contact. Such a system can be realized, e.g., by a suspended carbon nanotube quantum dot with a capacitive coupling to a gate contact. Focusing on the subgap transport regime, we analyze the inelastic Andreev reflections which drive the resonator to a nonequilibrium state. For small coupling, we obtain that vibration-assisted reflections can occur through two distinct interference paths. The interference determines the ratio between the rates of absorption and emission of vibrational energy quanta. We show that ground-state cooling of the mechanical oscillator can be achieved for many of the oscillator's modes simultaneously or for single modes selectively, depending on the experimentally tunable coupling to the superconductor.

  15. Understanding degenerate ground states of a protected quantum circuit in the presence of disorder

    NASA Astrophysics Data System (ADS)

    Dempster, Joshua M.; Fu, Bo; Ferguson, David G.; Schuster, D. I.; Koch, Jens

    2014-09-01

    A recent theoretical proposal suggests that a simple circuit utilizing two superinductors may produce a qubit with ground-state degeneracy [Brooks, Phys. Rev. A 87, 052306 (2013), 10.1103/PhysRevA.87.052306]. We perform a full circuit analysis along with exact diagonalization of the circuit Hamiltonian to elucidate the nature of the spectrum and low-lying wave functions of this 0-π device. We show that the ground-state degeneracy is robust to disorder in charge, flux, and critical current as well as insensitive to modest variations in the circuit parameters. Our treatment is nonperturbative, provides access to excited states and matrix elements, and is immediately applicable also to intermediate parameter regimes of experimental interest.

  16. Developing a state water plan: Ground-water conditions in Utah, spring of 1965

    USGS Publications Warehouse

    Arnow, Ted; Butler, R.G.; Mower, R.W.; Holman, N.B.; Cordova, R.M.; Carpenter, C.H.; Bjorklund, L.J.; Robinson, G.B. Jr.; Sandberg, G.W.

    1965-01-01

    This report is the second in a series of annual reports that describe ground-water conditions in Utah. It includes individual discussions of the most important areas of ground-water withdrawal in the State for the claendar year of 1964. Water-level fluctuations, however, are described for the period spring 1964 through spring 1965.The report was prepared cooperatively by the U.S. Geological Survey and the Utah Water and Power Board. Many of the data used in the preparation of the report were collected by the Geological Survey in cooperation with the Utah State Engineer. Some of the data for the number of wells constructed during 1964 were prepared by digital computer from the Utah Resources Information System data bank, University of Utah, using records that were compiled from the files of the Utah State Engineer.

  17. Quantum electrodynamics in strong electric fields: the ground-state Lamb shift in hydrogenlike uranium.

    PubMed

    Gumberidze, A; Stöhlker, Th; Banaś, D; Beckert, K; Beller, P; Beyer, H F; Bosch, F; Hagmann, S; Kozhuharov, C; Liesen, D; Nolden, F; Ma, X; Mokler, P H; Steck, M; Sierpowski, D; Tashenov, S

    2005-06-10

    X-ray spectra following radiative recombination of free electrons with bare uranium ions (U92+) were measured at the electron cooler of the ESR storage ring. The most intense lines observed in the spectra can be attributed to the characteristic Lyman ground-state transitions and to the recombination of free electrons into the K shell of the ions. Our experiment was carried out by utilizing the deceleration technique which leads to a considerable reduction of the uncertainties associated with Doppler corrections. This, in combination with the 0 degree observation geometry, allowed us to determine the ground-state Lamb shift in hydrogenlike uranium (U91+) from the observed x-ray lines with an accuracy of 1%. The present result is about 3 times more precise than the most accurate value available up to now and provides the most stringent test of bound-state quantum electrodynamics for one-electron systems in the strong-field regime.

  18. Diversity enabling equilibration: disorder and the ground state in artificial spin ice.

    PubMed

    Budrikis, Zoe; Politi, Paolo; Stamps, R L

    2011-11-18

    We report a novel approach to the question of whether and how the ground state can be achieved in square artificial spin ices where frustration is incomplete. We identify two sources of randomness that affect the approach to ground state: quenched disorder in the island response to fields and randomness in the sequence of driving fields. Numerical simulations show that quenched disorder can lead to final states with lower energy, and randomness in the sequence of driving fields always lowers the final energy attained by the system. We use a network picture to understand these two effects: disorder in island responses creates new dynamical pathways, and a random sequence of driving fields allows more pathways to be followed.

  19. Three-dimensional quantum calculations on the ground and excited state vibrations of ethylene

    NASA Astrophysics Data System (ADS)

    Groenenboom, Gerrit Cornelis

    Three dimensional potential energy surfaces of the ground and excited states of ethylene were calculated at the MRCEPA (Multi Reference Coupled Electronic Pair Approximation) level. The modes included are the torsion, the CC stretch, and the symmetric scissors. Full vibrational calculations were performed using the Lanczos/grid method. The avoided crossing between the V and the R state was dealt with in a diabetic model. The ground state results agree within 3 up to the highest vibrational level known experimentally. The origin and the maximum of the V back arrow N band are calculated at 5.68 and 7.82 eV, respectively, approximately 0.2 eV above the somewhat ambiguous experimental values. This work considerably diminishes the existing gap of approximately 0.5 eV between theory and experiment.

  20. Spectroscopy of ground and excited states of pseudoscalar and vector charmonium and bottomonium

    NASA Astrophysics Data System (ADS)

    Negash, Hluf; Bhatnagar, Shashank

    2016-07-01

    In this paper, we calculate the mass spectrum, weak decay constants, two photon decay widths, and two-gluon decay widths of ground (1S) and radially excited (2S, 3S,…) states of pseudoscalar charmoniuum and bottomonium such as ηc and ηb, as well as the mass spectrum and leptonic decay constants of ground state (1S), excited (2S, 1D, 3S, 2D, 4S,…, 5D) states of vector charmonium and bottomonium such as J/ψ, and Υ, using the formulation of Bethe-Salpeter equation under covariant instantaneous ansatz (CIA). Our results are in good agreement with data (where ever available) and other models. In this framework, from the beginning, we employ a 4 × 4 representation for two-body (qq¯) BS amplitude for calculating both the mass spectra as well as the transition amplitudes. However, the price we have to pay is to solve a coupled set of equations for both pseudoscalar and vector quarkonia, which we have explicitly shown get decoupled in the heavy-quark approximation, leading to mass spectral equation with analytical solutions for both masses, as well as eigenfunctions for all the above states, in an approximate harmonic oscillator basis. The analytical forms of eigenfunctions for ground and excited states so obtained are used to evaluate the decay constants and decay widths for different processes.