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1

Detection of beamsplitting attack in a quantum cryptographic channel based on photon number statistics monitoring  

NASA Astrophysics Data System (ADS)

Quantum cryptography in theory allows distributing secure keys between two users so that any performed eavesdropping attempt would be immediately discovered. However, in practice an eavesdropper can obtain key information from multi-photon states when attenuated laser radiation is used as a source. In order to overcome this possibility, it is generally suggested to implement special cryptographic protocols, like decoy states or SARG04. We present an alternative method based on monitoring photon number statistics after detection. This method can therefore be used with any existing protocol.

Gaidash, A. A.; Egorov, V. I.; Gleim, A. V.

2014-10-01

2

The statistical distribution of the number of counted scintillation photons in digital silicon photomultipliers: model and validation.  

PubMed

In the design and application of scintillation detectors based on silicon photomultipliers (SiPMs), e.g. in positron emission tomography imaging, it is important to understand and quantify the non-proportionality of the SiPM response due to saturation, crosstalk and dark counts. A new type of SiPM, the so-called digital silicon photomultiplier (dSiPM), has recently been introduced. Here, we develop a model of the probability distribution of the number of fired microcells, i.e. the number of counted scintillation photons, in response to a given amount of energy deposited in a scintillator optically coupled to a dSiPM. Based on physical and functional principles, the model elucidates the statistical behavior of dSiPMs. The model takes into account the photon detection efficiency of the detector; the light yield, excess variance and time profile of the scintillator; and the crosstalk probability, dark count rate, integration time and the number of microcells of the dSiPM. Furthermore, relations for the expectation value and the variance of the number of fired cells are deduced. These relations are applied in the experimental validation of the model using a dSiPM coupled to a LSO:Ce,Ca scintillator. Finally, we propose an accurate method for the correction of energy spectra measured with dSiPM-based scintillation detectors. PMID:22796633

van Dam, Herman T; Seifert, Stefan; Schaart, Dennis R

2012-08-01

3

Generalized binomial distribution in photon statistics  

E-print Network

The photon-number distribution between two parts of a given volume is found for an arbitrary photon statistics. This problem is related to the interaction of a light beam with a macroscopic device, for example a diaphragm, that separates the photon flux into two parts with known probabilities. To solve this problem, a Generalized Binomial Distribution (GBD) is derived that is applicable to an arbitrary photon statistics satisfying probability convolution equations. It is shown that if photons obey Poisson statistics then the GBD is reduced to the ordinary binomial distribution, whereas in the case of Bose-Einstein statistics the GBD is reduced to the Polya distribution. In this case, the photon spatial distribution depends on the phase-space volume occupied by the photons. This result involves a photon bunching effect, or collective behavior of photons that sharply differs from the behavior of classical particles. It is shown that the photon bunching effect looks similar to the quantum interference effect.

Aleksey Ilyin

2014-11-20

4

Photon-number statistics from resonance fluorescence of a two-level atom near a plasmonic nanoparticle  

NASA Astrophysics Data System (ADS)

The photon-number statistics from resonance fluorescence of a two-level atom near a metal nanosphere driven by a laser field with finite bandwidth is studied theoretically. Our analysis shows that all interesting physics here takes place in a small area around the nanosphere where the near field and the atom-nanosphere coupling essentially affect the radiative properties of the atom. Computer modeling estimates this area roughly as r ?2 a (r is the distance from the center of the nanosphere to the atom), with a being the radius of the nanosphere. At the larger distances, the influence of the nanoparticle vanishes and the atom tends to behave similarly to that in free space. It is shown that the distribution function p (n ,T ) of the emission probability of n photons in a given time interval T in steady-state resonance fluorescence drastically depends on the atom location around the nanosphere for r ?2 a , featuring a characteristic twist in the ridgelike dependence and a convergence time of up to 9 ? s, two orders of magnitude slower than for the atom in free space. At large distances, the distribution converges to a Gaussian one, as for the atom in free space. The typical convergence time scale at large distances r >2 a tends to the convergence time of the atom in free space. There are also two areas symmetrical around the nanosphere in which ? ˜? and the convergence time goes to zero. This behavior is determined by the interplay of the radiative and nonradiative decay rates of the atom due to the coupling with the metal nanosphere and by the near-field intensity. Additional parameters are the normalized laser frequency detuning from the atomic resonance and the bandwidth of the incoming laser field.

Pastukhov, Vladimir M.; Vladimirova, Yulia V.; Zadkov, Victor N.

2014-12-01

5

Photon statistics dispersion in excitonic composites  

E-print Network

Linear media are predicted to exist whose relative permiability is an operator in the space of quantum states of light. Such media are characterized by a photon statistics--dependent refractive index. This indicates a new type of optical dispersion -- the photon statistics dispersion. Interaction of quantum light with such media modifies the photon number distribution and, in particular, the degree of coherence of light. An excitonic composite -- a collection of noninteracting quantum dots -- is considered as a realization of the medium with the photon statistics dispersion. Expressions are derived for generalized plane waves in an excitonic composite and input--output relations for a planar layer of the material. Transformation rules for different photon initial states are analyzed. Utilization of the photon statistics dispersion in potential quantum--optical devices is discussed.

G. Ya. Slepyan; S. A. Maksimenko

2006-05-22

6

Characterization of photon statistics in a single-photon source via variable attenuation  

SciTech Connect

We propose a simple but effective scheme for characterizing photon-number statistics of a practical single-photon source. In this scheme, the variable attenuation method which frequently appears in decoy state quantum cryptography is utilized here to enhance the estimation of photon-number statistics. A much stricter bound for vacuum and single-photon proportions is obtained and this result, in turn, is shown to be applicable to the unconditional secure quantum cryptographic communication with single-photon devices.

Zhang Shengli [Key Laboratory of Quantum Information, University of Science and Technology of China (CAS), Hefei 230026 (China); Electronic Technology Institute, Information Engineering University, Zhengzhou, Henan 450004 (China); Zou Xubo; Li Chuanfeng; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China (CAS), Hefei 230026 (China); Jin Chenhui [Electronic Technology Institute, Information Engineering University, Zhengzhou, Henan 450004 (China)

2009-10-15

7

Tunable photon statistics in weakly nonlinear photonic molecules  

E-print Network

In recent studies [Liew et al., Phys. Rev. Lett. 104, 183601 (2010); Bamba et al., Phys. Rev. A 83, 021802(R) (2011)], due to destructive interference between different paths for two-photon excitation, strong photon antibunching can be obtained in a photonic molecule consisting of two coupled cavity modes with weak Kerr nonlinearity when one of the cavity modes is driven resonantly. Here, we study the photon statistics in a nonlinear photonic molecule with both the two cavity modes being driven coherently. We show that the statistical properties of the photons can be controlled by regulating the coupling constant between the cavity modes, the strength ratio and the relative phase between the driving fields. The photonic molecules with two driven modes can be used to generate tunable single-photon sources or controlled photonic quantum gates with weak Kerr nonlinearity.

Xun-Wei Xu; Yong Li

2014-07-11

8

Tunable photon statistics in weakly nonlinear photonic molecules  

NASA Astrophysics Data System (ADS)

In recent studies [Liew et al., Phys. Rev. Lett. 104, 183601 (2010), 10.1103/PhysRevLett.104.183601; Bamba et al., Phys. Rev. A 83, 021802(R) (2011), 10.1103/PhysRevA.83.021802], due to destructive interference between different paths for two-photon excitation, strong photon antibunching can be obtained in a photonic molecule consisting of two coupled cavity modes with weak Kerr nonlinearity when one of the cavity modes is driven resonantly. Here, we study the photon statistics in a nonlinear photonic molecule with both the two cavity modes being driven coherently. We show that the statistical properties of the photons can be controlled by regulating the strength ratio and the relative phase between the two driving fields. The photonic molecules with two driven modes can be used to generate tunable single-photon sources or controlled photonic quantum gates with weak Kerr nonlinearity.

Xu, Xun-Wei; Li, Yong

2014-10-01

9

Photon statistics: math versus mysticism  

NASA Astrophysics Data System (ADS)

Critical analysis is given for mystical aspects of the current understanding of interaction between charged particles: wave-particle duality and nonlocal entanglement. A possible statistical effect concerning distribution functions for coincidences between the output channels of beam splitters is described. If this effect is observed in beam splitter data, ten significant evidence for photon splitting, i.e. , against the notion that light is ultimately packaged in finite chunks, has been found. An argument is given for the invalidity of the meaning attached to tests of Bell inequalities. Additionally, a totally classical paradigm for the calculation of the customary expression for the "quantum" coincidence coefficient pertaining to the singlet state is described. If fully accounts for the results of experimental tests of Bell inequalities taken nowadays to prove the reality of entanglement and non-locality in quantum phenomena of, inter alia, light. Described. It fully accounts for the results of experimental tests of Bell inequalities take n nowadays to prove the reality of entanglement and non-locality in quantum phenomena of inter alia, light.

Kracklauer, A. F.

2013-10-01

10

On Photon Statistics in Variable Media  

E-print Network

We find explicit solutions of the Heisenberg equations of motion for a quadratic Hamiltonian, describing a generic model of variable media, in the case of multi-parameter squeezed input photons. The corresponding photon statistics are also derived in the Schroedinger picture in an abstract operator setting. Their time evolution is given in terms of solutions of certain Ermakov-type system. The unitary transformation and an extension of the squeeze/evolution operator are introduced formally.

Sergey I. Kryuchkov; Erwin Suazo; Sergei K. Suslov

2014-01-29

11

Counting statistics of collective photon transmissions  

SciTech Connect

We theoretically study cooperative effects in the steady-state transmission of photons through a medium of N radiators. Using methods from quantum transport, we find a cross-over in scaling from N to N{sup 2} in the current and to even higher powers of N in the higher cumulants of the photon counting statistics as a function of the tunable source occupation. The effect should be observable for atoms confined within a nano-cell with a pumped optical cavity as photon source. - Highlights: > Super-radiance transfers to super-transmittance in steady-state transport. > Higher cumulants are much more sensitive indicators for collective behavior than the first cumulant. > Effects should be measurable by pumped-cavity experiment.

Vogl, M., E-mail: malte.vogl@tu-berlin.de; Schaller, G., E-mail: gernot.schaller@tu-berlin.de; Brandes, T.

2011-10-15

12

Resolving photon number states in a superconducting circuit.  

PubMed

Electromagnetic signals are always composed of photons, although in the circuit domain those signals are carried as voltages and currents on wires, and the discreteness of the photon's energy is usually not evident. However, by coupling a superconducting quantum bit (qubit) to signals on a microwave transmission line, it is possible to construct an integrated circuit in which the presence or absence of even a single photon can have a dramatic effect. Such a system can be described by circuit quantum electrodynamics (QED)-the circuit equivalent of cavity QED, where photons interact with atoms or quantum dots. Previously, circuit QED devices were shown to reach the resonant strong coupling regime, where a single qubit could absorb and re-emit a single photon many times. Here we report a circuit QED experiment in the strong dispersive limit, a new regime where a single photon has a large effect on the qubit without ever being absorbed. The hallmark of this strong dispersive regime is that the qubit transition energy can be resolved into a separate spectral line for each photon number state of the microwave field. The strength of each line is a measure of the probability of finding the corresponding photon number in the cavity. This effect is used to distinguish between coherent and thermal fields, and could be used to create a photon statistics analyser. As no photons are absorbed by this process, it should be possible to generate non-classical states of light by measurement and perform qubit-photon conditional logic, the basis of a logic bus for a quantum computer. PMID:17268464

Schuster, D I; Houck, A A; Schreier, J A; Wallraff, A; Gambetta, J M; Blais, A; Frunzio, L; Majer, J; Johnson, B; Devoret, M H; Girvin, S M; Schoelkopf, R J

2007-02-01

13

Calibration of single-photon detectors using quantum statistics  

SciTech Connect

I show that calibration of the single-photon detector can be performed without knowledge of the signal parameters. Only partial information about the state statistics is sufficient for that. If one knows that the state is the squeezed one or the squeezed one mixed with the incoherent radiation, one can infer both the parameters of the state and the efficiency of the detector. For that one needs only to measure on/off statistics of detector clicks for the number of known absorbers placed before the detector. Thus, I suggest a scheme that performs a tomography of the signal and the measuring apparatus simultaneously.

Mogilevtsev, D. [Institute of Physics, Belarus National Academy of Sciences, F.Skarina Ave. 68, Minsk 220072 (Belarus) and Instituto de Fisica, UNICAMP, CP 6165, Campinas-SP, 13083-970 (Brazil)

2010-08-15

14

Photon statistics: Nonlinear spectroscopy of single quantum systems Shaul Mukamel  

E-print Network

Photon statistics: Nonlinear spectroscopy of single quantum systems Shaul Mukamel Department of their infor- mation content. A general formal expression for photon counting statistics from single quantum counting statistics which had proven to be a most valuable measure of coherence has been formulated

Mukamel, Shaul

15

Interaction of Fixed Number of Photons with Retinal Rod Cells  

NASA Astrophysics Data System (ADS)

New tools and approaches of quantum optics offer a unique opportunity to generate light pulses carrying a precise number of photons. Accurate control over the light pulses helps to improve the characterization of photoinduced processes. Here, we study interaction of a specialized light source which provides flashes containing just one photon, with retinal rod cells of Xenopus laevis toads. We provide unambiguous proof of the single-photon sensitivity of rod cells without relying on the statistical modeling. We determine their quantum efficiencies without the use of any precalibrated detectors and obtain the value of (29±4.7)%. Our approach provides the path for future studies and applications of quantum properties of light in phototransduction, vision, and photosynthesis.

Phan, Nam Mai; Cheng, Mei Fun; Bessarab, Dmitri A.; Krivitsky, Leonid A.

2014-05-01

16

Nonlinearity sensing via photon-statistics excitation spectroscopy  

SciTech Connect

We propose photon-statistics excitation spectroscopy as an adequate tool to describe the optical response of a nonlinear system. To this end we suggest to use optical excitation with varying photon statistics as another spectroscopic degree of freedom to gather information about the system in question. The responses of several simple model systems to excitation beams with different photon statistics are discussed. Possible spectroscopic applications in terms of identifying lasing operation are pointed out.

Assmann, Marc; Bayer, Manfred [Experimentelle Physik 2, Technische Universitaet Dortmund, D-44221 Dortmund (Germany)

2011-11-15

17

Linking numbers, spin, and statistics of solitons  

NASA Technical Reports Server (NTRS)

The spin and statistics of solitons in the (2 + 1)- and (3 + 1)-dimensional nonlinear sigma models is considered. For the (2 + 1)-dimensional case, there is the possibility of fractional spin and exotic statistics; for 3 + 1 dimensions, the usual spin-statistics relation is demonstrated. The linking-number interpretation of the Hopf invariant and the use of suspension considerably simplify the analysis.

Wilczek, F.; Zee, A.

1983-01-01

18

Ideal photon number amplifier and duplicator  

NASA Technical Reports Server (NTRS)

The photon number-amplification and number-duplication mechanism are analyzed in the ideal case. The search for unitary evolutions leads to consider also a number-deamplification mechanism, the symmetry between amplification and deamplification being broken by the integer-value nature of the number operator. Both transformations, amplification and duplication, need an auxiliary field which, in the case of amplification, turns out to be amplified in the inverse way. Input-output energy conservation is accounted for using a classical pump or through frequency-conversion of the fields. Ignoring one of the fields is equivalent to considering the amplifier as an open system involving entropy production. The Hamiltonians of the ideal devices are given and compared with those of realistic systems.

Dariano, G. M.

1992-01-01

19

Statistical Applets: Law of Large Numbers  

NSDL National Science Digital Library

Created by authors Duckworth, McCabe, Moore and Sclove for W.H. Freeman and Co., this applet is designed to help students understand the Law of Large Numbers by simulating rolling dice. The applet graphs the mean of the sum of the rolls for user specified conditions. This applet accompanies "Practice of Business Statistics;" however, it can be used without this text. Even though brief, this is still a nice interactive resource for an introductory statistics course.

Duckworth, William; Mccabe, George; Moore, David; Sclove, Stanley

2009-03-06

20

Steering photon statistics in single quantum dots: From one- to two-photon emission  

NASA Astrophysics Data System (ADS)

We present a combined experimental and theoretical study of two-photon emission from the biexciton cascade in single GaN quantum dots. By changing the biexciton binding energy, pump power, and temperature, the balance between the one- and two-photon decay processes is controlled in this four-level system, which drastically affects the photon statistics of the resulting emission. As the most pronounced feature of this interplay we observe a bunching phenomenon and a transition from sub- to super-Poissonian photon statistics, originating from the complex nature of the biexciton cascade. This work highlights how photon statistics can be steered between one- and two-photon processes towards an increased, bunched two-photon emission probability up to 50 K with the perspective for efficient photon pair generation in the UV spectral range.

Callsen, G.; Carmele, A.; Hönig, G.; Kindel, C.; Brunnmeier, J.; Wagner, M. R.; Stock, E.; Reparaz, J. S.; Schliwa, A.; Reitzenstein, S.; Knorr, A.; Hoffmann, A.; Kako, S.; Arakawa, Y.

2013-06-01

21

Photon-number discrimination without a photon counter and its application to reconstructing non-Gaussian states  

SciTech Connect

The nonlinearity of a conditional photon-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for photon-number resolution using only homodyne detection. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-photon-subtracted squeezed vacuum states. Although our photon-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, photon-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.

Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.; Hage, B.; Lam, P. K.; Symul, T. [Centre for Quantum Computation and Communication Technology, Quantum Optics group, Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Lund, A. P. [Centre for Quantum Computation and Communication Technology, Centre for Quantum Dynamics, Griffith University, Nathan QLD 4111 (Australia); Ralph, T. C. [Centre for Quantum Computation and Communication Technology, Department of Physics, University of Queensland, St. Lucia QLD 4072 (Australia)

2011-11-15

22

Significant Figures of Numbers in Statistical Tables  

Microsoft Academic Search

IT is a well-known fact that most numbers in statistical tables start with a small digit. For example, in population tables almost one third of the entries begin with the digit 1. The same holds true for most tables of the type occurring in the World's Almanac.

S. A. Goudsmit; W. H. Furry

1944-01-01

23

Testing photons' Bose-Einstein statistics with Compton scattering  

SciTech Connect

It is an empirical question whether photons always obey Bose-Einstein statistics, but devising and interpreting experimental tests of photon statistics can be a challenge. The nonrelativistic cross section for Compton scattering illustrates how a small admixture {nu} of wrong-sign statistics leads to a loss of gauge invariance; there is a large anomalous amplitude for scattering timelike photons. Nevertheless, one can interpret the observed transparency of the solar wind plasma at low frequencies as a bound {nu}<10{sup -25} if Lorentz symmetry is required. If there is instead a universal preferred frame, the bound is {nu}<10{sup -14}, still strong compared with previous results.

Altschul, Brett [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States)

2010-11-15

24

Joint multipartite photon statistics by on/off detection  

E-print Network

We demonstrate a method to reconstruct the joint photon statistics of two or more modes of radiation using on/off photodetection performed at different quantum efficiencies. The two-mode case is discussed in details and experimental results are presented for the bipartite states obtained after a beam-splitter fed by a single photon state or a thermal state.

G. Brida; M. Genovese; M. G. A. Paris; F. Piacentini

2006-06-23

25

Quantum entanglement of a large number of photons  

E-print Network

A bipartite multi-photon entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve photon number can be used to analyze such multi-photon states. Entanglement of up to 12 photons is detected using both the positivity of the partially transposed density matrix and a newly derived criteria. Furthermore, evidence is provided for entanglement of up to 100 photons. The multi-particle quantum state is such that even in the case of an overall photon collection and detection efficiency as low as a few percent, entanglement remains and can be detected.

Eisenberg, H S; Durkin, G A; Simon, C; Bouwmeester, D

2004-01-01

26

Coherent state statistics from time-resolved photon counting  

NASA Astrophysics Data System (ADS)

Time resolved photon counting was used to separate the different photon states emitted from a strongly attenuated laser source. We first describe a method to quantify the efficiency of our gated avalanche photo-detector, by relying on known Poissonian statistics. The detector was then optimized under different temperature and bias voltage conditions using the noise equivalent power as a metric. Finally, coherent pulses are sent into a ring cavity, such that the tapped output from the cavity forms a series of time multiplexed pulses, which then yield the photon counting statistics. We observed good agreement between theoretical estimates and experimental observations, to as low as 0.01% probability of detection.

Ravi, Harish; Prabhakar, Anil

2011-01-01

27

Photon statistics of coherent harmonic radiation of a linac free electron laser  

NASA Astrophysics Data System (ADS)

The subject of statistical fluctuations in a free electron laser (FEL) is both fundamental and significant to the understanding of FEL radiation. This dissertation deals with two relevant issues in this regard: the photon statistics of the visible coherent spontaneous harmonic radiation (CSHR); and the examination of the electron shot-noise interpretation of the observed statistical fluctuations. In this dissertation, we present the first experimental demonstration of the photon statistics of the FEL CSHR by the means of a photon counting experiment. We constructed the photon counting experiment for the 7th coherent spontaneous harmonic radiation on the Mark III FEL. The statistical property of the radiation is obtained by counting the number of photons emitted at an equivalent point in time for each member of an ensemble. The well- defined ensemble of radiation systems required for the experiment is achieved by suppressing the classical noise mainly associated with electron beam instabilities. The classical fluctuations are effectively suppressed through both the use of a trigger and the efforts to stabilizing the FEL gain and the electron beam. As a result, we measured the photon number fluctuations for the 7th CSHR generated by a series of identically prepared electron pulses. The experimental observation indicates that the 7th coherent spontaneous harmonic radiation displayed sub-Poisson photon statistics. On the other hand, numerical analysis is presented to investigate the validity of the shot-noise hypothesis. The shot-noise model has been relied on to explain the optical fluctuations observed in the FEL in the past. It attributes all observed statistical fluctuations to the shot-noise distribution in the density of the electron current. It will be shown that the electron shot-noise model is inadequate to explain the statistical fluctuations observed in the optical field.

Chen, Teng

28

A new type of photon-added squeezed coherent state and its statistical properties  

NASA Astrophysics Data System (ADS)

We construct a new type of photon-added squeezed coherent state generated by repeatedly operating the bosonic creation operator on a new type of squeezed coherent state [Fan H Y and Xiao M 1996 Phys. Lett. A 220 81]. We find that its normalization factor is related to single-variable Hermite polynomials. Furthermore, we investigate its statistical properties, such as Mandel's Q parameter, photon-number distribution, and Wigner function. The nonclassicality is displayed in terms of the intense oscillation of photon-number distribution and the negativity of the Wigner function.

Zhou, Jun; Fan, Hong-Yi; Song, Jun

2012-07-01

29

Excitations of photon-number states in Kerr nonlinear resonator at finite temperatures  

E-print Network

We investigate temperature reservoir effects in a lossy Kerr nonlinear resonator considering selective excitation of ooscillatory mode driven by a sequence of Gaussian pulses. In this way, we analyze time-dependent populations of photon-number states and quantum statistics on the base of second-order photon correlation function in one-photon and two-photon transitions. The effects coming from thermal reservoirs are interesting for performing more realistic approach to generate Fock states and for study phenomena connecting quantum engineering and temperature. We also study the role of pulse-shaping effects during selective excitation.

G. H. Hovsepyan; G. Yu. Kryuchkyan

2014-10-04

30

Imaging with a small number of photons.  

PubMed

Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. A high-quality digital camera based on a multi-megapixel array will typically record an image by collecting of order 10(5) photons per pixel, but by how much could this photon flux be reduced? In this work we demonstrate a single-photon imaging system based on a time-gated intensified camera from which the image of an object can be inferred from very few detected photons. We show that a ghost-imaging configuration, where the image is obtained from photons that have never interacted with the object, is a useful approach for obtaining images with high signal-to-noise ratios. The use of heralded single photons ensures that the background counts can be virtually eliminated from the recorded images. By applying principles of image compression and associated image reconstruction, we obtain high-quality images of objects from raw data formed from an average of fewer than one detected photon per image pixel. PMID:25557090

Morris, Peter A; Aspden, Reuben S; Bell, Jessica E C; Boyd, Robert W; Padgett, Miles J

2015-01-01

31

Imaging with a small number of photons  

NASA Astrophysics Data System (ADS)

Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. A high-quality digital camera based on a multi-megapixel array will typically record an image by collecting of order 105 photons per pixel, but by how much could this photon flux be reduced? In this work we demonstrate a single-photon imaging system based on a time-gated intensified camera from which the image of an object can be inferred from very few detected photons. We show that a ghost-imaging configuration, where the image is obtained from photons that have never interacted with the object, is a useful approach for obtaining images with high signal-to-noise ratios. The use of heralded single photons ensures that the background counts can be virtually eliminated from the recorded images. By applying principles of image compression and associated image reconstruction, we obtain high-quality images of objects from raw data formed from an average of fewer than one detected photon per image pixel.

Morris, Peter A.; Aspden, Reuben S.; Bell, Jessica E. C.; Boyd, Robert W.; Padgett, Miles J.

2015-01-01

32

Quantum nondemolition measurement of small photon numbers using stored light  

NASA Astrophysics Data System (ADS)

We propose a scheme for realizing a quantum nondemolition (QND) measurement of a small number of optical photons. Our scheme has two stages: First, we couple a propagating light pulse with fixed photon number to a trapped cold atomic gas within a cavity, such that the pulse is stored within a collective polariton mode. Second, a small-photon-number measurement is engineered by monitoring the cavity-transmission spectrum. Since the polariton mode profile is preserved during the process of detecting the spectrum, photon-number QND measurements could be achieved by retrieving the light pulse from the polariton mode. We also discuss a method which uses QND measurements to generate small-photon Fock states.

Liang, L.; Lin, G. W.; Hao, Y. M.; Niu, Y. P.; Gong, S. Q.

2014-11-01

33

Quantum Entanglement of a Large Number of Photons  

Microsoft Academic Search

A bipartite multiphoton entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve the photon number can be used to analyze such multiphoton states. Entanglement of up to 12 photons is detected using both the positivity of the partially-transposed density matrix and a newly derived

H. S. Eisenberg; G. Khoury; G. A. Durkin; C. Simon; D. Bouwmeester

2004-01-01

34

Quantum entanglement of a large number of photons  

E-print Network

A bipartite multiphoton entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve photon number can be used to analyze such multiphoton states. Entanglement of up to 12 photons is detected using both the positivity of the partially transposed density matrix and a newly derived criteria. Furthermore, evidence is provided for entanglement of up to 100 photons. The multi-particle quantum state is such that even in the case of an overall photon collection and detection efficiency as low as a few percent, entanglement remains and can be detected.

H. S. Eisenberg; G. Khoury; G. A. Durkin; C. Simon; D. Bouwmeester

2004-12-16

35

Quantum entanglement of a large number of photons.  

PubMed

A bipartite multiphoton entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve the photon number can be used to analyze such multiphoton states. Entanglement of up to 12 photons is detected using both the positivity of the partially-transposed density matrix and a newly derived criteria. Furthermore, evidence is provided for entanglement of up to 100 photons. The multiparticle quantum state is such that even in the case of an overall photon collection and detection efficiency as low as a few percent, entanglement remains and can be detected. PMID:15600835

Eisenberg, H S; Khoury, G; Durkin, G A; Simon, C; Bouwmeester, D

2004-11-01

36

Quantum Entanglement of a Large Number of Photons  

NASA Astrophysics Data System (ADS)

A bipartite multiphoton entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve the photon number can be used to analyze such multiphoton states. Entanglement of up to 12 photons is detected using both the positivity of the partially-transposed density matrix and a newly derived criteria. Furthermore, evidence is provided for entanglement of up to 100 photons. The multiparticle quantum state is such that even in the case of an overall photon collection and detection efficiency as low as a few percent, entanglement remains and can be detected.

Eisenberg, H. S.; Khoury, G.; Durkin, G. A.; Simon, C.; Bouwmeester, D.

2004-11-01

37

Calculation of Photon-Count Number Distributions via Master Equations  

PubMed Central

Fitting of photon-count number histograms is a way of analysis of fluorescence intensity fluctuations, a successor to fluorescence correlation spectroscopy. First versions of the theory for calculating photon-count number distributions have assumed constant emission intensity by a molecule during a counting time interval. For a long time a question has remained unanswered: to what extent is this assumption violated in experiments? Here we present a theory of photon-count number distributions that takes account of intensity fluctuations during a counting time interval. Theoretical count-number distributions are calculated via a numerical solution of Master equations (ME), which is a set of differential equations describing diffusion, singlet-triplet transitions, and photon emission. Detector afterpulsing and dead-time corrections are also included. The ME-theory is tested by fitting a series of photon-count number histograms corresponding to different lengths of the counting time interval. Compared to the first version of fluorescence intensity multiple distribution analysis theory introduced in 2000, the fit quality is significantly improved. It is discussed how a theory of photon-count number distributions, which assumes constant emission intensity during a counting time interval, may also yield a good fit quality. We argue that the spatial brightness distribution used in calculations of the fit curve is not the true spatial brightness distribution. Instead, a number of dynamic processes, which cause fluorescence intensity fluctuations, are indirectly taken into account via the profile adjustment parameters. PMID:16387771

Palo, Kaupo; Mets, Ülo; Loorits, Vello; Kask, Peet

2006-01-01

38

A Deterministic and Nondestructively-Verifiable Photon Number Source  

E-print Network

We present a deterministic approach based on continuous measurement and real-time quantum feedback control to prepare arbitrary photon number states of a cavity mode. The procedure passively monitors the number state actually achieved in each feedback stabilized measurement trajectory, thus providing a nondestructively verifiable photon source. The feasibility of a possible cavity QED implementation in the many-atom good-cavity coupling regime is analyzed.

JM Geremia

2006-03-23

39

Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength  

PubMed Central

Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110?nm FWHM) squeezed state in the telecom band centred at 1535?nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology. PMID:24694515

Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

2014-01-01

40

Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength.  

PubMed

Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110 nm FWHM) squeezed state in the telecom band centred at 1535 nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology. PMID:24694515

Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

2014-01-01

41

Photon-number-resolving detector with 10 bits of resolution  

SciTech Connect

A photon-number-resolving detector with single-photon resolution is described and demonstrated. It has 10 bits of resolution, does not require cryogenic cooling, and is sensitive to near ir wavelengths. This performance is achieved by flood illuminating a 32x32 element In{sub x}Ga{sub 1-x}AsP Geiger-mode avalanche photodiode array that has an integrated counter and digital readout circuit behind each pixel.

Jiang, Leaf A.; Dauler, Eric A.; Chang, Joshua T

2007-06-15

42

WHAT'S BEHIND THE NUMBERS? STATISTICAL SAMPLING  

Technology Transfer Automated Retrieval System (TEKTRAN)

Objective: The Nutrient Data Laboratory (NDL), USDA implemented the National Food and Nutrient Analysis Program (NFNAP) to obtain nationally representative estimates of the critical nutrients in highly consumed U.S. foods. The NFNAP is based on a statistically based sample design to identify locatio...

43

Sum-frequency generation from photon number squeezed light  

NASA Technical Reports Server (NTRS)

We investigate the quantum fluctuations of the fields produced in sum-frequency (SF) generation from light initially in the photon number squeezed state. It is found that, to the fourth power term, the output SF light is sub-Poissonian whereas the quantum fluctuations of the input beams increase. Quantum anticorrelation also exists in SF generation.

Wu, Ling-An; Du, Cong-Shi; Wu, Mei-Juan; Li, Shi-Qun

1994-01-01

44

High quantum-efficiency photon-number-resolving detector for photonic on-chip information processing.  

PubMed

The integrated optical circuit is a promising architecture for the realization of complex quantum optical states and information networks. One element that is required for many of these applications is a high-efficiency photon detector capable of photon-number discrimination. We present an integrated photonic system in the telecom band at 1550 nm based on UV-written silica-on-silicon waveguides and modified transition-edge sensors capable of number resolution and over 40 % efficiency. Exploiting the mode transmission failure of these devices, we multiplex three detectors in series to demonstrate a combined 79 % ± 2 % detection efficiency with a single pass, and 88 % ± 3 % at the operating wavelength of an on-chip terminal reflection grating. Furthermore, our optical measurements clearly demonstrate no significant unexplained loss in this system due to scattering or reflections. This waveguide and detector design therefore allows the placement of number-resolving single-photon detectors of predictable efficiency at arbitrary locations within a photonic circuit - a capability that offers great potential for many quantum optical applications. PMID:24104153

Calkins, Brice; Mennea, Paolo L; Lita, Adriana E; Metcalf, Benjamin J; Kolthammer, W Steven; Lamas-Linares, Antia; Spring, Justin B; Humphreys, Peter C; Mirin, Richard P; Gates, James C; Smith, Peter G R; Walmsley, Ian A; Gerrits, Thomas; Nam, Sae Woo

2013-09-23

45

Measurements of the dependence of the photon-number distribution on the number of modes in parametric down-conversion.  

PubMed

Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results. PMID:22330466

Dovrat, L; Bakstein, M; Istrati, D; Shaham, A; Eisenberg, H S

2012-01-30

46

Measurements of the dependence of the photon-number distribution on the number of modes in parametric down-conversion  

E-print Network

Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to directly observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results.

L. Dovrat; M. Bakstein; D. Istrati; A. Shaham; H. S. Eisenberg

2012-01-03

47

Statistical error in particle simulations of low mach number flows  

SciTech Connect

We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. The expressions are derived using equilibrium statistical mechanics. The results show that the number of samples needed to adequately resolve the flowfield scales as the inverse square of the Mach number. Agreement of the theory with direct Monte Carlo simulations shows that the use of equilibrium theory is justified.

Hadjiconstantinou, N G; Garcia, A L

2000-11-13

48

Nonclassical imaging via photon-number fluctuation correlation  

E-print Network

We report an experimental study on a nonclassical imaging mechanism. By achieving a convolution between the aperture function of the object and the photon-number fluctuation correlation function of thermal light, we isolated a resolved image from the unresolved classical image as well as the autocorrelation of two identical unresolved classical images. The remarkable feature of this mechanism is that its imaging resolution depends on the angular size of the light source instead of that of the imaging lens.

Jane N. Sprigg; Tao Peng; Yanhua Shih

2014-10-23

49

Photon number amplification/duplication through parametric conversion  

NASA Technical Reports Server (NTRS)

The performance of parametric conversion in achieving number amplification and duplication is analyzed. It is shown that the effective maximum gains G(sub *) remain well below their integer ideal values, even for large signals. Correspondingly, one has output Fano factors F(sub *) which are increasing functions of the input photon number. On the other hand, in the inverse (deamplifier/recombiner) operating mode quasi-ideal gains G(sub *) and small factors F(sub *) approximately equal to 10 percent are obtained. Output noise and non-ideal gains are ascribed to spontaneous parametric emission.

Dariano, G. M.; Macchiavello, C.; Paris, M.

1993-01-01

50

Photon-number distributions of twin beams generated in spontaneous parametric down-conversion and measured by an intensified CCD camera  

E-print Network

The measurement of photon-number statistics of fields composed of photon pairs, generated in spontaneous parametric down-conversion and detected by an intensified CCD camera is described. Final quantum detection efficiencies, electronic noises, finite numbers of detector pixels, transverse intensity spatial profiles of the detected beams as well as losses of single photons from a pair are taken into account in a developed general theory of photon-number detection. The measured data provided by an iCCD camera with single-photon detection sensitivity are analyzed along the developed theory. Joint signal-idler photon-number distributions are recovered using the reconstruction method based on the principle of maximum likelihood. The range of applicability of the method is discussed. The reconstructed joint signal-idler photon-number distribution is compared with that obtained by a method that uses superposition of signal and noise and minimizes photoelectron entropy. Statistics of the reconstructed fields are identified to be multi-mode Gaussian. Elements of the measured as well as the reconstructed joint signal-idler photon-number distributions violate classical inequalities. Sub-shot-noise correlations in the difference of the signal and idler photon numbers as well as partial suppression of odd elements in the distribution of the sum of signal and idler photon numbers are observed.

Jan Perina Jr; Ondrej Haderka; Martin Hamar; Vaclav Michalek

2012-02-07

51

Predicting landfalling hurricane numbers from basin hurricane numbers: basic statistical analysis  

E-print Network

One possible method for predicting landfalling hurricane numbers is to first predict the number of hurricanes in the basin and then convert that prediction to a prediction of landfalling hurricane numbers using an estimated proportion. Should this work better than just predicting landfalling hurricane numbers directly? We perform a basic statistical analysis of this question in the context of a simple abstract model.

Laepple, T; Penzer, J; Bellone, E; Nzerem, K; Laepple, Thomas; Jewson, Stephen; Penzer, Jeremy; Bellone, Enrica; Nzerem, Kechi

2007-01-01

52

Observation of squeezed states with strong photon-number oscillations  

SciTech Connect

Squeezed states of light constitute an important nonclassical resource in the field of high-precision measurements, for example, gravitational wave detection, as well as in the field of quantum information, for example, for teleportation, quantum cryptography, and distribution of entanglement in quantum computation networks. Strong squeezing in combination with high purity, high bandwidth, and high spatial mode quality is desirable in order to achieve significantly improved performances contrasting any classical protocols. Here we report on the observation of 11.5 dB of squeezing, together with relatively high state purity corresponding to a vacuum contribution of less than 5%, and a squeezing bandwidth of about 170 MHz. The analysis of our squeezed states reveals a significant production of higher-order pairs of quantum-correlated photons and the existence of strong photon-number oscillations.

Mehmet, Moritz [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Institut fuer Gravitationsphysik, Leibniz Universitaet Hannover, Callinstrasse 38, D-30167 Hannover (Germany); Centre for Quantum Engineering and Space-Time Research (QUEST), Leibniz Universitaet Hannover, Welfengarten 1, D-30167 Hannover (Germany); Vahlbruch, Henning; Lastzka, Nico; Danzmann, Karsten; Schnabel, Roman [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Institut fuer Gravitationsphysik, Leibniz Universitaet Hannover, Callinstrasse 38, D-30167 Hannover (Germany)

2010-01-15

53

The Entropy Photon-Number Inequality and its Consequences  

E-print Network

Determining the ultimate classical information carrying capacity of electromagnetic waves requires quantum-mechanical analysis to properly account for the bosonic nature of these waves. Recent work has established capacity theorems for bosonic single-user, broadcast, and wiretap channels, under the presumption of two minimum output entropy conjectures. Despite considerable accumulated evidence that supports the validity of these conjectures, they have yet to be proven. Here we show that the preceding minimum output entropy conjectures are simple consequences of an Entropy Photon-Number Inequality, which is a conjectured quantum-mechanical analog of the Entropy Power Inequality (EPI) from classical information theory.

Saikat Guha; Baris I. Erkmen; Jeffrey H. Shapiro

2007-10-30

54

A Superposition Technique for Deriving Photon Scattering Statistics in Plane-Parallel Cloudy Atmospheres  

NASA Technical Reports Server (NTRS)

Photon transport in a multiple scattering medium is critically dependent on scattering statistics, in particular the average number of scatterings. A superposition technique is derived to accurately determine the average number of scatterings encountered by reflected and transmitted photons within arbitrary layers in plane-parallel, vertically inhomogeneous clouds. As expected, the resulting scattering number profiles are highly dependent on cloud particle absorption and solar/viewing geometry. The technique uses efficient adding and doubling radiative transfer procedures, avoiding traditional time-intensive Monte Carlo methods. Derived superposition formulae are applied to a variety of geometries and cloud models, and selected results are compared with Monte Carlo calculations. Cloud remote sensing techniques that use solar reflectance or transmittance measurements generally assume a homogeneous plane-parallel cloud structure. The scales over which this assumption is relevant, in both the vertical and horizontal, can be obtained from the superposition calculations. Though the emphasis is on photon transport in clouds, the derived technique is applicable to any scattering plane-parallel radiative transfer problem, including arbitrary combinations of cloud, aerosol, and gas layers in the atmosphere.

Platnick, S.

1999-01-01

55

Photon statistics and LWI in three-level media  

E-print Network

their three levels, that is the density matrix characterizing the initial state of the j-th atom is p?(tt s) 0 p(tis) = 0 p (t, . ) lp (t?)l"' (2 I) 0 Ip (t 0)lc ' P ( 0) where tie is the time is enters the radiation cavity. Assuming that the time spent...-level atoms driven by a single field A. Photon Number Calculation The density matrix element p??? (n[p]n) obeys the equation of motion: = ? ? Q ( [H', P'] ?, ?+ [H', P']i i + [H', P'] ) (2. 4) r9~ V, i ~, Pt +, , ?? P, ?s?+, Vs?i, ~~+ V, ?~i. rP~+, a...

Sariyianni, Zoe-Elizabeth

2002-01-01

56

A brief history of numbers and statistics with cytometric applications.  

PubMed

A brief history of numbers and statistics traces the development of numbers from prehistory to completion of our current system of numeration with the introduction of the decimal fraction by Viete, Stevin, Burgi, and Galileo at the turn of the 16th century. This was followed by the development of what we now know as probability theory by Pascal, Fermat, and Huygens in the mid-17th century which arose in connection with questions in gambling with dice and can be regarded as the origin of statistics. The three main probability distributions on which statistics depend were introduced and/or formalized between the mid-17th and early 19th centuries: the binomial distribution by Pascal; the normal distribution by de Moivre, Gauss, and Laplace, and the Poisson distribution by Poisson. The formal discipline of statistics commenced with the works of Pearson, Yule, and Gosset at the turn of the 19th century when the first statistical tests were introduced. Elementary descriptions of the statistical tests most likely to be used in conjunction with cytometric data are given and it is shown how these can be applied to the analysis of difficult immunofluorescence distributions when there is overlap between the labeled and unlabeled cell populations. PMID:11241502

Watson, J V

2001-02-15

57

REVSTAT Statistical Journal Volume 11, Number 3, November 2013, 231254  

E-print Network

density and distribution functions are obtained in terms of confluent hypergeometric functionsREVSTAT ­ Statistical Journal Volume 11, Number 3, November 2013, 231­254 AN ACCURATE APPROXIMATION methodology for approximating the distribution of a general linear combination of non-central chi

Alves, Maria Isabel Fraga

58

The creation of large photon-number path entanglement conditioned on photodetection  

E-print Network

Large photon-number path entanglement is an important resource for enhanced precision measurements and quantum imaging. We present a general constructive protocol to create any large photon number path-entangled state based on the conditional detection of single photons. The influence of imperfect detectors is considered and an asymptotic scaling law is derived.

Pieter Kok; Hwang Lee; Jonathan P. Dowling

2001-12-01

59

Generation of optical 'Schrödinger cats' from photon number states.  

PubMed

Schrödinger's cat is a Gedankenexperiment in quantum physics, in which an atomic decay triggers the death of the cat. Because quantum physics allow atoms to remain in superpositions of states, the classical cat would then be simultaneously dead and alive. By analogy, a 'cat' state of freely propagating light can be defined as a quantum superposition of well separated quasi-classical states-it is a classical light wave that simultaneously possesses two opposite phases. Such states play an important role in fundamental tests of quantum theory and in many quantum information processing tasks, including quantum computation, quantum teleportation and precision measurements. Recently, optical Schrödinger 'kittens' were prepared; however, they are too small for most of the aforementioned applications and increasing their size is experimentally challenging. Here we demonstrate, theoretically and experimentally, a protocol that allows the generation of arbitrarily large squeezed Schrödinger cat states, using homodyne detection and photon number states as resources. We implemented this protocol with light pulses containing two photons, producing a squeezed Schrödinger cat state with a negative Wigner function. This state clearly exhibits several quantum phase-space interference fringes between the 'dead' and 'alive' components, and is large enough to become useful for quantum information processing and experimental tests of quantum theory. PMID:17700695

Ourjoumtsev, Alexei; Jeong, Hyunseok; Tualle-Brouri, Rosa; Grangier, Philippe

2007-08-16

60

On the Euclidean version of the photon number integral  

SciTech Connect

We reconsider the Euclidean version of the photon number integral introduced by Stodolsky [Acta Phys. Pol. B 33, 2659 (2002), e-print hep-th/02053131].This integral is well defined for any smooth non-self-intersecting curve in R{sup N}. Besides studying general features of this integral (including its conformal invariance), we evaluate it explicitly for the ellipse. The result is n{sub ellipse}=({xi}{sup -1}+{xi}){pi}{sup 2}, where {xi} is the ratio of the minor and major axes. This is in agreement with the previous result n{sub circle}=2{pi}{sup 2} and also with the conjecture that the minimum value of n for any plane curve occurs for the circle.

Ruijsenaars, S.; Stodolsky, L. [Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT (United Kingdom); Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Munich (Germany)

2008-02-15

61

Photon statistics of coherent harmonic radiation of a linac free electron laser  

Microsoft Academic Search

The subject of statistical fluctuations in a free electron laser (FEL) is both fundamental and significant to the understanding of FEL radiation. This dissertation deals with two relevant issues in this regard: the photon statistics of the visible coherent spontaneous harmonic radiation (CSHR); and the examination of the electron shot-noise interpretation of the observed statistical fluctuations. In this dissertation, we

Teng Chen

1999-01-01

62

Biexciton Quantum Yield of Single Semiconductor Nanocrystals from Photon Statistics  

E-print Network

Biexciton properties strongly affect the usability of a light emitter in quantum photon sources and lasers but are difficult to measure for single fluorophores at room temperature due to luminescence intermittency and ...

Bawendi, Moungi G.

63

Unified single-photon and single-electron counting statistics: From cavity QED to electron transport  

SciTech Connect

A key ingredient of cavity QED is the coupling between the discrete energy levels of an atom and photons in a single-mode cavity. The addition of periodic ultrashort laser pulses allows one to use such a system as a source of single photons--a vital ingredient in quantum information and optical computing schemes. Here we analyze and time-adjust the photon-counting statistics of such a single-photon source and show that the photon statistics can be described by a simple transport-like nonequilibrium model. We then show that there is a one-to-one correspondence of this model to that of nonequilibrium transport of electrons through a double quantum dot nanostructure, unifying the fields of photon-counting statistics and electron-transport statistics. This correspondence empowers us to adapt several tools previously used for detecting quantum behavior in electron-transport systems (e.g., super-Poissonian shot noise and an extension of the Leggett-Garg inequality) to single-photon-source experiments.

Lambert, Neill [Advanced Science Institute, RIKEN, Saitama 351-0198 (Japan); Chen, Yueh-Nan [Department of Physics and National Center for Theoretical Sciences, National Cheng-Kung University, Tainan 701, Taiwan (China); Nori, Franco [Advanced Science Institute, RIKEN, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

2010-12-15

64

Statistical distributions of earthquake numbers: consequence of branching process  

NASA Astrophysics Data System (ADS)

We discuss various statistical distributions of earthquake numbers. Previously, we derived several discrete distributions to describe earthquake numbers for the branching model of earthquake occurrence: these distributions are the Poisson, geometric, logarithmic and the negative binomial (NBD). The theoretical model is the `birth and immigration' population process. The first three distributions above can be considered special cases of the NBD. In particular, a point branching process along the magnitude (or log seismic moment) axis with independent events (immigrants) explains the magnitude/moment-frequency relation and the NBD of earthquake counts in large time/space windows, as well as the dependence of the NBD parameters on the magnitude threshold (magnitude of an earthquake catalogue completeness). We discuss applying these distributions, especially the NBD, to approximate event numbers in earthquake catalogues. There are many different representations of the NBD. Most can be traced either to the Pascal distribution or to the mixture of the Poisson distribution with the gamma law. We discuss advantages and drawbacks of both representations for statistical analysis of earthquake catalogues. We also consider applying the NBD to earthquake forecasts and describe the limits of the application for the given equations. In contrast to the one-parameter Poisson distribution so widely used to describe earthquake occurrence, the NBD has two parameters. The second parameter can be used to characterize clustering or overdispersion of a process. We determine the parameter values and their uncertainties for several local and global catalogues, and their subdivisions in various time intervals, magnitude thresholds, spatial windows, and tectonic categories. The theoretical model of how the clustering parameter depends on the corner (maximum) magnitude can be used to predict future earthquake number distribution in regions where very large earthquakes have not yet occurred.

Kagan, Yan Y.

2010-03-01

65

Biexciton quantum yield of single semiconductor nanocrystals from photon statistics.  

PubMed

Biexciton properties strongly affect the usability of a light emitter in quantum photon sources and lasers but are difficult to measure for single fluorophores at room temperature due to luminescence intermittency and bleaching at the high excitation fluences usually required. Here, we observe the biexciton (BX) to exciton (X) to ground photoluminescence cascade of single colloidal semiconductor nanocrystals (NCs) under weak excitation in a g((2)) photon correlation measurement and show that the normalized amplitude of the cascade feature is equal to the ratio of the BX to X fluorescence quantum yields. This imposes a limit on the attainable depth of photon antibunching and provides a robust means to study single emitter biexciton physics. In NC samples, we show that the BX quantum yield is considerably inhomogeneous, consistent with the defect sensitivity expected of the Auger nonradiative recombination mechanism. The method can be extended to study X,BX spectral and polarization correlations. PMID:21288042

Nair, Gautham; Zhao, Jing; Bawendi, Moungi G

2011-03-01

66

Biexciton quantum yield of single semiconductor nanocrystals from photon statistics  

PubMed Central

Biexciton properties strongly affect the usability of a light emitter in quantum photon sources and lasers but are difficult to measure for single fluorophores at room temperature due to luminescence intermittency and bleaching at the high excitation fluences usually required. Here, we observe the biexciton (BX) to exciton (X) to ground photoluminescence cascade of single colloidal semiconductor nanocrystals (NCs) under weak excitation in a g(2) photon correlation measurement and show that the normalized amplitude of the cascade feature is equal to the ratio of the BX to X fluorescence quantum yields. This imposes a limit on the attainable depth of photon antibunching and provides a robust means to study single emitter biexciton physics. In NC samples, we show that the BX quantum yield is considerably inhomogeneous, consistent with the defect sensitivity expected of the Auger nonradiative recombination mechanism. The method can be extended to study X,BX spectral and polarization correlations. PMID:21288042

Nair, Gautham; Zhao, Jing; Bawendi, Moungi G

2012-01-01

67

The Effect of Partial Coherence on the Statistics of Single-Photon Pulses Propagating in the Atmosphere  

E-print Network

The photon density operator function is used to describe the propagation of single-photon pulses through a turbulent atmosphere. The effects of statistical properties of photon source and the effects of a random phase screen on the variance of photon counting are studied. A procedure for reducing the total noise is discussed. The physical mechanisms responsible for this reduction are explained.

G. P. Berman; A. A. Chumak

2007-02-26

68

Generation of entangled states of large photon numbers  

Microsoft Academic Search

Using intense amplified short pulses, stimulated parametric down-conversion has been studied. We generated and characterized two polarization entangled spatial modes containing up to 50 indistinguishable photon pairs

H. S. Eisenberg; D. Bouwmester

2004-01-01

69

Statistics of Lagrangian Variables in High Reynolds Number Turbulence  

NASA Astrophysics Data System (ADS)

We report the use of a high speed imaging system to record the 3D trajectories of tracer particles in a turbulent water flow between counter-rotating disks, with 300 < R_? < 1000. Particles with diameters as small as 25 microns can be tracked at frame rates up to 75kHz with spatial resolution of 512 pixels. This spatial and temporal resolution is sufficient to measure particle accelerations over times significantly less than the Kolmogorov time. The system is used to measure the statistics of Lagrangian variables and study their scaling with Reynolds number. We find a strongly non-Gaussian acceleration distribution with stretched exponential tails. The acceleration variance exhibits Kolmogorov scaling at large Reynolds number, and may be compared with DNS results at smaller Reynolds number(P. Vedula and P. K. Yeung, Physics of Fluids 11, p. 1208 (1999)). We also observe and characterize rare large acceleration events. Additional information is available at http:// milou.msc.cornell.edu/turbulence.html.

La Porta, A.; Voth, Greg A.; Crawford, Alice M.; Bodenschatz, Eberhard; Alexander, Jim

2000-03-01

70

Large numbers hypothesis. III. Kinetic theory, statistical physics, and thermodynamics  

NASA Astrophysics Data System (ADS)

Dirac's large numbers hypothesis (LNH) is incorporated into kinetic theory, statistical physics, and thermodynamics using the self-consistent formalism of units covariance. The ingeodesic equation and matter creation introduce modifications of the most fundamental laws of the subject. Liouville's theorem no longer holds, the Boltzmann equation is modified, as is the H-theorem. This affects the second law of thermodynamics in that for canonical LNH neither reversible nor adiabatic processes are possible (as expected). A significant result is that the collision terms have the same form as in standard physics. This means that equilibrium distribution functions are identical to those of standard physics, as required for self-consistency with the precepts of LNH. The net effect of LNH is as though all matter in our Universe were weakly coupled to a large heat bath.

Adams, Peter J.

1983-05-01

71

Effective Atomic Numbers of Lanthanides with Gamma Radiation for Photon Energy Absorption  

NASA Astrophysics Data System (ADS)

Effective atomic numbers for photon energy absorption, ZPEA,eff have been calculated for photon from 1 keV to 20 MeV for selected oxides of lanthanides, such as Lanthanum oxide, Cerium oxide, Samarium oxide, Europium oxide, Dysprosium oxide, Thulium oxide, Ytterbium oxide. The ZPEA,eff values then compared with ZPI,eff for photon interaction. The ZPEA,eff values have been found to change with energy and composition of selected lanthanides. Oxides of lanthanides are considered as better shielding materials to the exposure of gamma radiation. The values of effective atomic number for photon energy absorption help in the calculation of absorbed dose.

Shantappa, Anil; Hanagodimath, S. M.

72

Multi-bit quantum random number generation by measuring positions of arrival photons.  

PubMed

We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator. PMID:25362380

Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

2014-10-01

73

Multi-bit quantum random number generation by measuring positions of arrival photons  

NASA Astrophysics Data System (ADS)

We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator.

Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

2014-10-01

74

Spatial Resolution Enhancement in Quantum Imaging beyond the Diffraction Limit Using Entangled Photon-Number State  

E-print Network

In this paper we study the resolution of images illuminated by sources composed of $N+1$ photons in which one non-degenerate photon is entangled with $N$ degenerate photons. The $N$ degenerate photons illuminate an object and are collected by an $N$ photon detector. The signal from the $N$ photon detector is measured in coincidence with the non-degenerate photon giving rise to a ghost image. We discuss the case of three photons in various configurations and generalize to $N+1$. Using the Rayleigh criterion, we find that the system may give an improvement in resolution by a factor of $N$ compared to using a classical source. For the case that the $N$-photon number detector is a point detector, a coherent image is obtained. If the $N$-photon detector is a bucket detector, the image is incoherent. The visibility of the image in both cases is 1. In the opposite case in which the non-degenerate photon is scattered by the object, then, using an $N$-photon point detector may reduce the Airy disk by a factor of $N$.

Jianming Wen; Morton H. Rubin; Yanhua Shih

2008-12-12

75

Inexpensive electronics and software for photon statistics and correlation spectroscopy  

NASA Astrophysics Data System (ADS)

Single-molecule-sensitive microscopy and spectroscopy are transforming biophysics and materials science laboratories. Techniques such as fluorescence correlation spectroscopy (FCS) and single-molecule sensitive fluorescence resonance energy transfer (FRET) are now commonly available in research laboratories but are as yet infrequently available in teaching laboratories. We describe inexpensive electronics and open-source software that bridges this gap, making state-of-the-art research capabilities accessible to undergraduates interested in biophysics. We include a discussion of the intensity correlation function relevant to FCS and how it can be determined from photon arrival times. We demonstrate the system with a measurement of the hydrodynamic radius of a protein using FCS that is suitable for the undergraduate teaching laboratory. The FPGA-based electronics, which are easy to construct, are suitable for more advanced measurements as well, and several applications are described. As implemented, the system has 8 ns timing resolution, can control up to four laser sources, and can collect information from as many as four photon-counting detectors.

Gamari, Benjamin D.; Zhang, Dianwen; Buckman, Richard E.; Milas, Peker; Denker, John S.; Chen, Hui; Li, Hongmin; Goldner, Lori S.

2014-07-01

76

The Numbers Game: The Top 10 Sources for Statistics.  

ERIC Educational Resources Information Center

Lists and describes the 10 best sources for answering statistical questions that are available for free or at a low cost on the World Wide Web. Statistics search tips, government publishers, almanacs, and newspapers are discussed. (LRW)

Berinstein, Paula

1998-01-01

77

Evolution of the statistical properties of photons passed through a traveling-wave laser amplifier  

NASA Astrophysics Data System (ADS)

The evolution of the photon statistics of a light beam is described as it passes through a traveling-wave laser amplifier, modeled as a birth-death-immigration (BDI) medium. The relationship between the input and output probability distributions and probability generating functions with given (but possibly varying) birth, death, and immigration rates for arbitrary input statistics is obtained. The photon statistics at the output of a general BDI traveling-wave amplifier are always broader than those at the input, and they can take many forms. The most general solution can be applied when the input distribution to the amplifier takes the form of a negative-binomial transform. The results are useful in calculating the performance characteristics of lightwave systems using optical amplifiers in which the object is to detect light with a broad range of statistical properties, including scattered light, spontaneous-emission light, and light emitted from a laser.

Diament, Paul; Teich, Malvin C.

1992-05-01

78

Volume 114. number 4 CHEMICAL PHYSICS LETTERS 8 March I985 UNIFIED THEORY OF PHOTON ECHOES  

E-print Network

Volume 114. number 4 CHEMICAL PHYSICS LETTERS 8 March I985 UNIFIED THEORY OF PHOTON ECHOES] and arbitrary concentration with weak mtermolecular m- teractions [4] _ Although the behavior of the echo signal of lmpurtty transition energies. In thss case, the photon echo pulse sequence wiil produce a ~vell-de~ne~ echo

Mukamel, Shaul

79

Direct measurement of the dependence of the photon-number distribution on the number of modes in parametric down-conversion  

E-print Network

Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to directly observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results.

Dovrat, L; Istrati, D; Shaham, A; Eisenberg, H S

2011-01-01

80

Measurement of Photon Statistics with Live Photoreceptor Cells  

E-print Network

We analyzed the electrophysiological response of an isolated rod photoreceptor of Xenopus laevis under stimulation by coherent and pseudo-thermal light sources. Using the suction electrode technique for single cell recordings and a fiber optics setup for light delivery allowed measurements of the major statistical characteristics of the rod response. The results indicate differences in average responses of rod cells to coherent and pseudo-thermal light of the same intensity and also differences in signal-to-noise ratios and second order intensity correlation functions. These findings should be relevant for interdisciplinary studies seeking applications of quantum optics in biology.

Nigel Sim; Mei Fun Cheng; Dmitri Bessarab; C. Michael Jones; Leonid A. Krivitsky

2012-01-13

81

Measurement of Photon Statistics with Live Photoreceptor Cells  

NASA Astrophysics Data System (ADS)

We analyzed the electrophysiological response of an isolated rod photoreceptor of Xenopus laevis under stimulation by coherent and pseudothermal light sources. Using the suction-electrode technique for single cell recordings and a fiber optics setup for light delivery allowed measurements of the major statistical characteristics of the rod response. The results indicate differences in average responses of rod cells to coherent and pseudothermal light of the same intensity and also differences in signal-to-noise ratios and second-order intensity correlation functions. These findings should be relevant for interdisciplinary studies seeking applications of quantum optics in biology.

Sim, Nigel; Cheng, Mei Fun; Bessarab, Dmitri; Jones, C. Michael; Krivitsky, Leonid A.

2012-09-01

82

Beating the Abbe diffraction limit in confocal microscopy via nonclassical photon statistics.  

PubMed

We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the nonclassical photon statistics of single nitrogen-vacancy color centers in diamond. By developing a general model of superresolution based on the direct sampling of the kth-order autocorrelation function of the photoluminescence signal, we show the possibility to resolve, in principle, arbitrarily close emitting centers. PMID:25325642

Gatto Monticone, D; Katamadze, K; Traina, P; Moreva, E; Forneris, J; Ruo-Berchera, I; Olivero, P; Degiovanni, I P; Brida, G; Genovese, M

2014-10-01

83

Beating the Abbe Diffraction Limit in Confocal Microscopy via Nonclassical Photon Statistics  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the nonclassical photon statistics of single nitrogen-vacancy color centers in diamond. By developing a general model of superresolution based on the direct sampling of the kth-order autocorrelation function of the photoluminescence signal, we show the possibility to resolve, in principle, arbitrarily close emitting centers.

Gatto Monticone, D.; Katamadze, K.; Traina, P.; Moreva, E.; Forneris, J.; Ruo-Berchera, I.; Olivero, P.; Degiovanni, I. P.; Brida, G.; Genovese, M.

2014-10-01

84

Practical photon number detection with electric field-modulated silicon avalanche photodiodes.  

PubMed

Low-noise single-photon detection is a prerequisite for quantum information processing using photonic qubits. In particular, detectors that are able to accurately resolve the number of photons in an incident light pulse will find application in functions such as quantum teleportation and linear optics quantum computing. More generally, such a detector will allow the advantages of quantum light detection to be extended to stronger optical signals, permitting optical measurements limited only by fluctuations in the photon number of the source. Here we demonstrate a practical high-speed device, which allows the signals arising from multiple photon-induced avalanches to be precisely discriminated. We use a type of silicon avalanche photodiode in which the lateral electric field profile is strongly modulated in order to realize a spatially multiplexed detector. Clearly discerned multiphoton signals are obtained by applying sub-nanosecond voltage gates in order to restrict the detector current. PMID:22273682

Thomas, O; Yuan, Z L; Shields, A J

2012-01-01

85

Photon-photon correlation statistics in the collective emission from ensembles of self-assembled quantum dots  

E-print Network

We present a theoretical analysis of the intensity autocorrelation for the spontaneous emission from a planar ensemble of self-assembled quantum dots. Using the quantum jump approach, we numerically simulate the evolution of the system and construct photon-photon delay time statistics that approximates the second order correlation function of the field. The form of this correlation function in the case of collective emission from a highly homogeneous ensemble qualitatively differs form that characterizing an ensemble of independent emitters (inhomogeneous ensemble of uncoupled dots). The signatures of collective emission in the intensity correlations are observed also in the case of an inhomogeneous but sufficiently strongly coupled ensemble. Thus, we show that the second order correlation function of the emitted field provides a sensitive test of cooperative effects.

Fitria Miftasani; Pawe? Machnikowski

2014-07-17

86

Disability and Employment. Disability Statistics Abstract Number 11.  

ERIC Educational Resources Information Center

This statistical abstract summarizes recent data on the relationship between disability and employment. The statistics come from the Current Population Survey, the Census Bureau's Survey of Income and Program Participation, a poll of 1,000 Americans with disabilities, and administrative data on recipients of Social Security Disability Insurance…

LaPlante, Mitchell P.; Kennedy, Jae; Kaye, H. Stephen; Wenger, Barbara L.

87

Characterization of strong light-matter coupling in semiconductor quantum-dot microcavities via photon-statistics spectroscopy  

E-print Network

It is shown that spectrally resolved photon-statistics measurements of the resonance fluorescence from realistic semiconductor quantum-dot systems allow for high contrast identification of the two-photon strong-coupling states. Using a microscopic theory, the second-rung resonance is analyzed and optimum excitation conditions are determined. The computed photon-statistics spectrum displays gigantic, experimentally robust resonances at the energetic positions of the second-rung emission.

L. Schneebeli; M. Kira; S. W. Koch

2008-01-23

88

Characterization of Strong Light-Matter Coupling in Semiconductor Quantum-Dot Microcavities via Photon-Statistics Spectroscopy  

Microsoft Academic Search

It is shown that spectrally resolved photon-statistics measurements of the resonance fluorescence from realistic semiconductor quantum-dot systems allow for high contrast identification of the two-photon strong-coupling states. Using a microscopic theory, the second-rung resonance of Jaynes-Cummings ladder is analyzed and optimum excitation conditions are determined. The computed photon-statistics spectrum displays gigantic, experimentally robust resonances at the energetic positions of the

L. Schneebeli; M. Kira; S. W. Koch

2008-01-01

89

Statistical Error in Particle Simulations of Low Mach Number Flows  

E-print Network

We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. Expressions for the fluid velocity, density and temperature are derived ...

Hadjiconstantinou, Nicolas G.

90

Crunching Numbers: What Cancer Screening Statistics Really Tell Us  

Cancer.gov

Cancer screening studies have shown that more screening does not necessarily translate into fewer cancer deaths. This article explains how to interpret the statistics used to describe the results of screening studies.

91

Grant Title: METHODOLOGY, MEASUREMENT, AND STATISTICS Funding Opportunity Number: NSF 12-510.  

E-print Network

Grant Title: METHODOLOGY, MEASUREMENT, AND STATISTICS Funding Opportunity Number: NSF 12; Division of Social and Economic Sciences. Area of Research: Proposals that are methodologically innovative: The Methodology, Measurement, and Statistics (MMS) Program is an interdisciplinary program in the Social

Farritor, Shane

92

Super-resolving single-photon number-path-entangled state and its generation  

NASA Astrophysics Data System (ADS)

In this paper, we propose two protocols for generating super-resolving single-photon (SRSP) number-path-entangled states from general maximally number-path-entangled NOON states. It is our purpose to show that, contrary to popular belief, a field in a single-photon state can carry multifold phase information. We also show that both protocols generate the desired state with different probabilities depending on the type of detectors being used. Such SRSP number-path-entangled states preserve high resolving power but lack the requirement of a multiphoton absorbing resist, which may serve as a proof-of-principle prototype for quantum lithography in the future.

Feng, Wei; Jiang, Kebei; Lollie, Michelle L.-J.; Zubairy, M. Suhail; Dowling, Jonathan P.

2014-04-01

93

Security of decoy-state protocols for general photon-number-splitting attacks  

NASA Astrophysics Data System (ADS)

Decoy-state protocols provide a way to defeat photon-number-splitting attacks in quantum cryptography implemented with weak coherent pulses. We point out that previous security analyses of such protocols relied on assumptions about eavesdropping attacks that considered treating each pulse equally and independently. We give an example to demonstrate that, without such assumptions, the security parameters of previous decoy-state implementations could be worse than the ones claimed. Next we consider more general photon-number-splitting attacks, which correlate different pulses, and give an estimation procedure for the number of single-photon signals with rigorous security statements. The impact of our result is that previous analyses of the number of times a decoy-state quantum cryptographic system can be reused before it makes a weak key must be revised.

Somma, Rolando D.; Hughes, Richard J.

2013-06-01

94

Highly sensitive, photon number resolving detectors mediated by phonons using $?$-doped GaAs transistors  

E-print Network

We report a photon number resolving detector using two-dimensional electron gas (2DEG) based transistors. When the photon pulses impinge on the absorption region, the generated phonons dissipate ballistically in the 2DEG toward the trench isolated nanowire transistors near the surface. The phonon-electron interaction induces a positive conductance in the transistors, resulting in a current increase. With this principle, we obtain an internal quantum efficiency for this type of detector of up to 85%.

Xiulai Xu; Hugh Baker; David A. Williams

2010-05-03

95

Absolute calibration of photon-number-resolving detectors with an analog output using twin beams  

SciTech Connect

A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

Pe?ina, Jan, E-mail: jan.perina.jr@upol.cz [RCPTM, Joint Laboratory of Optics of Palacký University and Institute of Physics AS CR, 17. listopadu 12, 77146 Olomouc (Czech Republic); Haderka, Ond?ej [Joint Laboratory of Optics of Palacký University and Institute of Physics AS CR, 17. listopadu 12, 771 46 Olomouc (Czech Republic); Allevi, Alessia [Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria, I-22100 Como (Italy); Bondani, Maria [Istituto di Fotonica e Nanotecnologie, CNR-IFN, I-22100 Como (Italy)

2014-01-27

96

Photon-number correlations in waveguide lattices with second order coupling  

NASA Astrophysics Data System (ADS)

We introduce second-order coupling into the transport and coupling of photons in waveguide lattices. Second-order coupling, as well as high-order couplings, can be significant in long, compact or some special lattices, and is important for large-scale quantum circuits. Photon-number correlations with various amounts of second-order couplings are calculated. Some distinctive and interesting effects arise, and these are helpful for our comprehension of quantum walks in waveguide lattices.

Qi, F.; Feng, Z. G.; Wang, Y. F.; Xu, P.; Zhu, S. N.; Zheng, W. H.

2014-12-01

97

Design of Narrowband Optical Filters Using Binary Number Sequence Photonic Crystals  

Microsoft Academic Search

A theory to design narrow band optical filters by using a new photonic crystal structure is presented. This new photonic crystal\\u000a structure is composed of low index layers and high index layers arranged in mod. 4 up and down binary number sequence. The\\u000a new structure exhibits narrow transmission peaks in the forbidden frequency gap region with high optical transmission (greater

Anirudh Banerjee

2008-01-01

98

Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics  

E-print Network

Data from the Fermi Large Area Telescope suggests that there is an extended excess of GeV gamma-ray photons in the Inner Galaxy. Identifying potential astrophysical sources that contribute to this excess is an important step in verifying whether the signal originates from annihilating dark matter. In this paper, we focus on the potential contribution of unresolved point sources, such as millisecond pulsars (MSPs). We propose that the statistics of the photons---in particular, the flux probability distribution function (PDF) of the photon counts below the point-source detection threshold---can potentially distinguish between the dark-matter and point-source interpretations. We calculate the flux PDF via the method of generating functions for these two models of the excess. Working in the framework of Bayesian model comparison, we then demonstrate that the flux PDF can potentially provide evidence for an unresolved MSP-like point-source population.

Lee, Samuel K; Safdi, Benjamin R

2014-01-01

99

Statistical model for spiky clutter using dominant scatterer number fluctuations  

Microsoft Academic Search

The concept of a fluctuating number of scatterers is used to derive a family of multiparameter clutter probability density functions (PDFs). The simplest nontrivial case describes a Gaussian background plus a fluctuating number of dominant scatterers, each having a Rayleigh distributed amplitude. The derived clutter radar cross section (RCS) describe the bimodal or spiky behavior of certain types of clutter,

Teodoro Azzarelli; T Gilfillan

1991-01-01

100

Pulse pileup statistics for energy discriminating photon counting x-ray detectors  

SciTech Connect

Purpose: Energy discriminating photon counting x-ray detectors can be subject to a wide range of flux rates if applied in clinical settings. Even when the incident rate is a small fraction of the detector's maximum periodic rate N{sub 0}, pulse pileup leads to count rate losses and spectral distortion. Although the deterministic effects can be corrected, the detrimental effect of pileup on image noise is not well understood and may limit the performance of photon counting systems. Therefore, the authors devise a method to determine the detector count statistics and imaging performance. Methods: The detector count statistics are derived analytically for an idealized pileup model with delta pulses of a nonparalyzable detector. These statistics are then used to compute the performance (e.g., contrast-to-noise ratio) for both single material and material decomposition contrast detection tasks via the Cramer-Rao lower bound (CRLB) as a function of the detector input count rate. With more realistic unipolar and bipolar pulse pileup models of a nonparalyzable detector, the imaging task performance is determined by Monte Carlo simulations and also approximated by a multinomial method based solely on the mean detected output spectrum. Photon counting performance at different count rates is compared with ideal energy integration, which is unaffected by count rate. Results: The authors found that an ideal photon counting detector with perfect energy resolution outperforms energy integration for our contrast detection tasks, but when the input count rate exceeds 20%N{sub 0}, many of these benefits disappear. The benefit with iodine contrast falls rapidly with increased count rate while water contrast is not as sensitive to count rates. The performance with a delta pulse model is overoptimistic when compared to the more realistic bipolar pulse model. The multinomial approximation predicts imaging performance very close to the prediction from Monte Carlo simulations. The monoenergetic image with maximum contrast-to-noise ratio from dual energy imaging with ideal photon counting is only slightly better than with dual kVp energy integration, and with a bipolar pulse model, energy integration outperforms photon counting for this particular metric because of the count rate losses. However, the material resolving capability of photon counting can be superior to energy integration with dual kVp even in the presence of pileup because of the energy information available to photon counting. Conclusions: A computationally efficient multinomial approximation of the count statistics that is based on the mean output spectrum can accurately predict imaging performance. This enables photon counting system designers to directly relate the effect of pileup to its impact on imaging statistics and how to best take advantage of the benefits of energy discriminating photon counting detectors, such as material separation with spectral imaging.

Wang, Adam S.; Harrison, Daniel; Lobastov, Vladimir; Tkaczyk, J. Eric [Departments of Electrical Engineering and Radiology, Stanford University, Stanford, California 94305 (United States); GE Global Research Center, Niskayuna, New York 12309 (United States)

2011-07-15

101

Posting Number: 0601800 Title: Assist/Assoc/Full Professor (Applied Statistics/Biostatistics)  

E-print Network

Posting Number: 0601800 Title: Assist/Assoc/Full Professor (Applied Statistics/Biostatistics) Working Title: Assist/Assoc/Full Professor (Applied Statistics/Biostatistics) Department: Mathematical in the general area of Applied Statistics/Biostatistics. The Department is particularly interested in candidates

Shepp, Larry

102

Volume 11 Number 7 1983 Nucleic Acids Research Statistical characterizationof nucleic acid sequence functional domains  

E-print Network

Volume 11 Number 7 1983 Nucleic Acids Research Statistical characterizationof nucleic acid sequence among these domains but suggest others. The ability of these simple statistics of nucleic acid sequences body of nucleic acid sequence data. In this study we review the statistical characteristics

Waterman, Michael S.

103

The Statistics of the Number of Neutron Collisions Prior to Absorption  

E-print Network

The Statistics of the Number of Neutron Collisions Prior to Absorption Sara A. Pozzi* Oak Ridge Accepted July 25, 2005 Abstract ­ We propose a simple analytical model to describe the statistics, the energy transfer and the collision num- ber are related quantities, and therefore, the statistics of

Pázsit, Imre

104

Photon-number entangled states generation model with stimulated parametric down conversion  

E-print Network

We address the process of generation of the photon-number entangled states of light in the stimulated nonlinear parametric down conversion process and build the simple model describing the generation, not involving the traditional parametric approximation. The motion equations for the system of pumping and two-mode outgoing field are solved for the case of the strong correlation between two modes, the evolution of the state parameters of the generated modes is obtained. The solution is briefly analyzed for particular types of photon-number entangled states.

Gurin, Oleksandr O; Usenko, Constantin V

2008-01-01

105

Photon-number entangled states generation model with stimulated parametric down conversion  

E-print Network

We address the process of generation of the photon-number entangled states of light in the stimulated nonlinear parametric down conversion process and build the simple model describing the generation, not involving the traditional parametric approximation. The motion equations for the system of pumping and two-mode outgoing field are solved for the case of the strong correlation between two modes, the evolution of the state parameters of the generated modes is obtained. The solution is briefly analyzed for particular types of photon-number entangled states.

Oleksandr O. Gurin; Vladyslav C. Usenko; Constantin V. Usenko

2008-07-08

106

REVSTAT Statistical Journal Volume 7, Number 1, April 2009, 5566  

E-print Network

the means by which this measure could be developed as a costing element for a health impact assessment tool FOR THE HEALTH COST OF COLD HOUSING: AN APPLICATION OF GAMLSS Authors: Robert Gilchrist ­ STORM, London, and are also particularly susceptible to cold-related health effects. The significant numbers recognised

Alves, Maria Isabel Fraga

107

REVSTAT Statistical Journal Volume 9, Number 1, March 2011, 5781  

E-print Network

of time points. We first introduce linear models for repeated measurements with focus on general linear mixed effects models. For the analysis of repeated measurements it is common to assume independence of repeated measure- ments on a number of subjects at a series of time points. In this work we will only

Alves, Maria Isabel Fraga

108

Photon-number entangled states generation model with stimulated parametric down conversion  

Microsoft Academic Search

We address the process of generation of the photon-number entangled states of light in the stimulated nonlinear parametric down conversion process and build the simple model describing the generation, not involving the traditional parametric approximation. The motion equations for the system of pumping and two-mode outgoing field are solved for the case of the strong correlation between two modes, the

Oleksandr O. Gurin; Vladyslav C. Usenko; Constantin V. Usenko

2008-01-01

109

Generation of optical coherent-state superpositions by number-resolved photon subtraction from the squeezed vacuum  

SciTech Connect

We have created heralded coherent-state superpositions (CSSs) by subtracting up to three photons from a pulse of squeezed vacuum light. To produce such CSSs at a sufficient rate, we used our high-efficiency photon-number-resolving transition edge sensor to detect the subtracted photons. This experiment is enabled by and utilizes the full photon-number-resolving capabilities of this detector. The CSS produced by three-photon subtraction had a mean-photon number of 2.75{sub -0.24}{sup +0.06} and a fidelity of 0.59{sub -0.14}{sup +0.04} with an ideal CSS. This confirms that subtracting more photons results in higher-amplitude CSSs.

Gerrits, Thomas; Glancy, Scott; Clement, Tracy S.; Calkins, Brice; Lita, Adriana E.; Nam, Sae Woo; Mirin, Richard P.; Knill, Emanuel [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Miller, Aaron J. [Albion College, Albion, Michigan 49224 (United States); Migdall, Alan L. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

2010-09-15

110

Characteristics of Noise and Photon Statistics of Fiber Components in Electro-Optical Systems  

NASA Astrophysics Data System (ADS)

This thesis presents a comprehensive study of the role of the fiber replicator in electro-optical systems. In the all fiber optical diagnostic system for the National Ignition Facility's DANTE data acquisition system running at 1550nm, the 8x fiber replicator was used to increase the SNR (Signal to Noise Ratio) of single-shot, electrical pulse measurements. In the system, Mach-Zehnder modulators were used to convert the electrical signals into optical signals. The fiber replicator was used to create identical copies of the optical signals. A High SNR was achieved through the averaging of these duplicated signals. Erbium-doped fiber amplifiers (EDFAs) were built to amplify the optical signals after the fiber replicator. The EDFAs applied in the DANTEEO system should have high gain, low noise, low background signals and high pulse-shape fidelity. In this thesis, we discussed the effect of different configurations and the type of Er-doped fibers on the gain and noise performance of EDFAs. We also used a simplified model for dynamic gain in EDFAs to explore the effect of the EDFA on the shape of the amplified pulse. Based on this model, the calculated pulse-shape distortions were found to be dependent on the EDFA configuration and the optical gain. We also investigated the photon statistics with the fiber replicator in a photon entanglement system. The entangled photons were created through the up-conversion and down-conversion of a Q-switch laser beam running at 1053nm. The different behavior between entangled photon and non-entangled single photons in the system with the fiber replicator are discussed.

Zhao, Cheng

111

Photonic analog-to-digital converter based on the robust symmetrical number system  

NASA Astrophysics Data System (ADS)

A novel approach to realizing photonic analog-to-digital conversion with Gray-code-like property is proposed and demonstrated. Instead of using Mach-Zehnder modulators (MZMs) with different half-wave voltages, an array of MZMs with identical half-wave voltages are applied to realize quantization and encoding, which greatly simplifies the implementation. Multiple comparators with preset thresholds are applied at the output of each MZM to improve the number of bits. Through properly setting the bias voltages of the MZMs, a photonic analog to digital converter (ADC) based on the robust symmetrical number system (RSNS) coding method is realized. As an example, a 3-channel structure with maximum quantization level of 17 (corresponding to 4.09 bits) is investigated in detail. We show that the differential encoding technique can be applied in the proposed structure, which increases the equivalent number of bits of the ADC system.

Chen, Ying; Chi, Hao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

2012-11-01

112

Quantum key distribution using vacuum-one-photon qubits: maximum number of transferable bits per particle  

E-print Network

Quantum key distribution schemes which employ encoding on vacuum-one-photon qubits are capable of transferring more information bits per particle than the standard schemes employing polarization or phase coding. We calculate the maximum number of classical bits per particle that can be securely transferred when the key distribution is performed with the BB84 and B92 protocols, respectively, using the vacuum-one-photon qubits. In particular, we show that for a generalized B92 protocol with the vacuum-one-photon qubits, a maximum of two bits per particle can be securely transferred. We also demonstrate the advantage brought about by performing a generalized measurement that is optimized for unambiguous discrimination of the encoded states: the parameter range where the transfer of two bits per particle can be achieved is dramatically enhanced as compared to the corresponding parameter range of projective measurements.

Su-Yong Lee; Se-Wan Ji; Hai-Woong Lee; Jae-Weon Lee; Janos A. Bergou

2009-07-20

113

Comparing different approaches for generating random numbers device-independently using a photon pair source  

NASA Astrophysics Data System (ADS)

What is the most efficient way to generate random numbers device-independently using a photon pair source based on spontaneous parametric down conversion? We consider this question by comparing two implementations of a detection-loophole-free Bell test. In particular, we study in detail a scenario where a source is used to herald path-entangled states, i.e. entanglement between two spatial modes sharing a single photon and where non-locality is revealed using photon counting preceded by small displacement operations. We start by giving a theoretical description of such a measurement. We then show how to optimize the Bell–CHSH violation through a non-perturbative calculation, taking the main experimental imperfections into account. We finally bound the amount of randomness that can be extracted and compare it to the one obtained with the conventional scenario using photon pairs entangled e.g. in polarization and analyzed through photon counting. While the former requires higher overall detection efficiencies, it is far more efficient in terms of the entropy per experimental run and under reasonable assumptions, it provides higher random bit rates.

Caprara Vivoli, V.; Sekatski, P.; Bancal, J.-D.; Lim, C. C. W.; Martin, A.; Thew, R. T.; Zbinden, H.; Gisin, N.; Sangouard, N.

2015-02-01

114

On some special cases of the Entropy Photon-Number Inequality  

E-print Network

We show that the Entropy Photon-Number Inequality (EPnI) holds where one of the input states is the vacuum state and for several candidates of the other input state that includes the cases when the state has the eigenvectors as the number states and either has only two non-zero eigenvalues or has arbitrary number of non-zero eigenvalues but is a high entropy state. We also discuss the conditions, which if satisfied, would lead to an extension of these results.

Smarajit Das; Naresh Sharma; Siddharth Muthukrishnan

2011-07-12

115

Photon statistics and speckle visibility spectroscopy with partially coherent X-rays.  

PubMed

A new approach is proposed for measuring structural dynamics in materials from multi-speckle scattering patterns obtained with partially coherent X-rays. Coherent X-ray scattering is already widely used at high-brightness synchrotron lightsources to measure dynamics using X-ray photon correlation spectroscopy, but in many situations this experimental approach based on recording long series of images (i.e. movies) is either not adequate or not practical. Following the development of visible-light speckle visibility spectroscopy, the dynamic information is obtained instead by analyzing the photon statistics and calculating the speckle contrast in single scattering patterns. This quantity, also referred to as the speckle visibility, is determined by the properties of the partially coherent beam and other experimental parameters, as well as the internal motions in the sample (dynamics). As a case study, Brownian dynamics in a low-density colloidal suspension is measured and an excellent agreement is found between correlation functions measured by X-ray photon correlation spectroscopy and the decay in speckle visibility with integration time obtained from the analysis presented here. PMID:25343797

Li, Luxi; Kwa?niewski, Pawe?; Orsi, Davide; Wiegart, Lutz; Cristofolini, Luigi; Caronna, Chiara; Fluerasu, Andrei

2014-11-01

116

Joint measurement of photon-number sum and phase-difference operators in a two-mode field  

SciTech Connect

We present an experimental scheme that realizes joint measurement of photon-number sum and phase-difference operators on a two-mode field. The proposed scheme only involves linear optical elements and photon detectors with single-photon sensitivity. Furthermore, we demonstrate that such a measurement setup can be applied to generate two-mode N-photon entangled states from a pair of squeezed vacuum states. These N-photon entangled states are useful resources for quantum-information processing, high-precision frequency measurement, and quantum optical lithography.

Zou Xubo; Pahlke, K.; Mathis, W. [Electromagnetic Theory Group at THT, Department of Electrical Engineering, University of Hannover, D-30167 Hannover (Germany)

2003-10-01

117

Photon number resolution enables quantum receiver for realistic coherent optical communications  

NASA Astrophysics Data System (ADS)

Quantum-enhanced measurements can provide information about the properties of a physical system with sensitivities beyond what is fundamentally possible with conventional technologies. However, this advantage can be achieved only if quantum measurement technologies are robust against losses and real-world imperfections, and can operate in regimes compatible with existing systems. Here, we demonstrate a quantum receiver for coherent communication, the performance of which not only surpasses the standard quantum limit, but does so for input powers extending to high mean photon numbers. This receiver uses adaptive measurements and photon number resolution to achieve high sensitivity and robustness against imperfections, and ultimately shows the greatest advantage over the standard quantum limit ever achieved by any quantum receiver at power levels compatible with state-of-the-art optical communication systems. Our demonstration shows that quantum measurements can provide real and practical advantages over conventional technologies for optical communications.

Becerra, F. E.; Fan, J.; Migdall, A.

2015-01-01

118

True random number generator based on discretized encoding of the time interval between photons.  

PubMed

We propose an approach to generate true random number sequences based on the discretized encoding of the time interval between photons. The method is simple and efficient, and can produce a highly random sequence several times longer than that of other methods based on threshold or parity selection, without the need for hashing. A proof-of-principle experiment has been performed, showing that the system could be easily integrated and applied to quantum cryptography and other fields. PMID:23456008

Li, Shen; Wang, Long; Wu, Ling-An; Ma, Hai-Qiang; Zhai, Guang-Jie

2013-01-01

119

Applications of simulator computed tomography number for photon dose calculations during radiotherapy treatment planning  

Microsoft Academic Search

Purpose: To study the variation of computed tomography (CT) number from a simulator-based scanner and the effect of this variation on photon-dose calculations.Method and materials: CT images of a cylindrical phantom with multiple inserts were obtained using a commercially-available simulator-CT (Ximatron: Varian, Palo Alto, CA). The linear correlation coefficient and Chi-square methods were used to determine the X-ray effective energy

James C. H. Chu; Ben Ni; Robert Kriz; V. Amod Saxena

2000-01-01

120

Photon-number entangled states generated in Kerr media with optical parametric pumping  

SciTech Connect

Two nonlinear Kerr oscillators mutually coupled by parametric pumping are studied as a source of states entangled in photon numbers. Temporal evolution of entanglement quantified by negativity shows the effects of sudden death and birth of entanglement. Entanglement is preserved even in asymptotic states under certain conditions. The role of reservoirs at finite temperature in entanglement evolution is elucidated. Relation between generation of entangled states and violation of Cauchy-Schwartz inequality for oscillator intensities is found.

Kowalewska-Kudlaszyk, A.; Leonski, W.; Perina, Jan Jr. [Nonlinear Optics Division, Department of Physics, Adam Mickiewicz University, Umultowska 85, PL-61-614 Poznan (Poland)

2011-05-15

121

Attacks exploiting deviation of mean photon number in quantum key distribution and coin-tossing  

E-print Network

The security of quantum communication using a weak coherent source requires an accurate knowledge of the source's mean photon number. Finite calibration precision or an active manipulation by an attacker may cause the actual emitted photon number to deviate from the known value. We model effects of this deviation on the security of three quantum communication protocols: the Bennett-Brassard 1984 (BB84) quantum key distribution (QKD) protocol without decoy states, Scarani-Acin-Ribordy-Gisin 2004 (SARG04) QKD protocol, and a coin-tossing protocol. For QKD, we model both a strong attack using technology possible in principle, and a realistic attack bounded by today's technology. To maintain the mean photon number in two-way systems, such as plug-and-play and relativistic quantum cryptography schemes, bright pulse energy incoming from the communication channel must be monitored. Implementation of a monitoring detector has largely been ignored so far, except for ID Quantique's commercial QKD system Clavis2. We scrutinize this implementation for security problems, and show that designing a hack-proof pulse-energy-measuring detector is far from trivial. Indeed the first implementation has three serious flaws confirmed experimentally, each of which may be exploited in a cleverly constructed Trojan-horse attack. We discuss requirements for a loophole-free implementation of the monitoring detector.

Shihan Sajeed; Igor Radchenko; Sarah Kaiser; Jean-Philippe Bourgoin; Anna Pappa; Laurent Monat; Matthieu Legre; Vadim Makarov

2014-12-27

122

Unified position-dependent photon-number quantization in layered structures  

E-print Network

We have recently developed a position-dependent quantization scheme for describing the ladder and effective photon-number operators associated with the electric field to analyze quantum optical energy transfer in lossy and dispersive dielectrics [Phys. Rev. A, 89, 033831 (2014)]. While having a simple connection to the thermal balance of the system, these operators only described the electric field and its coupling to lossy dielectric bodies. Here we extend this field quantization scheme to include the magnetic field and thus to enable description of the total electromagnetic field and discuss conceptual measurement schemes to verify the predictions. In addition to conveniently describing the formation of thermal balance, the generalized approach allows modeling of the electromagnetic pressure and Casimir forces. We apply the formalism to study the local steady state field temperature distributions and electromagnetic force density in cavities with cavity walls at different temperatures. The calculated local electric and magnetic field temperatures exhibit oscillations that depend on the position as well as the photon energy. However, the effective photon number and field temperature associated with the total electromagnetic field is always position-independent in lossless media. Furthermore, we show that the direction of the electromagnetic force varies as a function of frequency, position, and material thickness.

Mikko Partanen; Teppo Häyrynen; Jani Oksanen; Jukka Tulkki

2014-12-01

123

Unified position-dependent photon-number quantization in layered structures  

NASA Astrophysics Data System (ADS)

We have recently developed a position-dependent quantization scheme for describing the ladder and effective photon-number operators associated with the electric field to analyze quantum optical energy transfer in lossy and dispersive dielectrics [Phys. Rev. A 89, 033831 (2014), 10.1103/PhysRevA.89.033831]. While having a simple connection to the thermal balance of the system, these operators only described the electric field and its coupling to lossy dielectric bodies. Here we extend this field quantization scheme to include the magnetic field and thus to enable description of the total electromagnetic field and discuss conceptual measurement schemes to verify the predictions. In addition to conveniently describing the formation of thermal balance, the generalized approach allows modeling of the electromagnetic pressure and Casimir forces. We apply the formalism to study the local steady-state field temperature distributions and electromagnetic force density in cavities with cavity walls at different temperatures. The calculated local electric and magnetic field temperatures exhibit oscillations that depend on the position as well as the photon energy. However, the effective photon number and field temperature associated with the total electromagnetic field is always position independent in lossless media. Furthermore, we show that the direction of the electromagnetic force varies as a function of frequency, position, and material thickness.

Partanen, Mikko; Häyrynen, Teppo; Oksanen, Jani; Tulkki, Jukka

2014-12-01

124

Probabilistic and statistical relationships between number of vehicles and number of visitors at a geologic site in a National Park  

USGS Publications Warehouse

The National Park Service needs to establish in all of the national parks how large the parking lots should be in order to enjoy and presence our natural resources, for example, in the Delicate Arch in the Arches National Park. Probabilistic and statistical relationships were developed between the number of vehicles (N) at one time in the Wolfe Ranch parking lot and the number of visitors (X) at Delicate Arch 1.5 miles away in the Arches National Park, southeastern Utah. The value of N is determined such that 30 or more visitors are at the arch only 10% of the time.

Crovelli, R.A.

1997-01-01

125

Fluorescence lifetimes and correlated photon statistics from single CdSe/oligo(phenylene vinylene) composite nanostructures.  

PubMed

We present measurements of fluorescence intensity trajectories and associated excited-state decay times from individual CdSe/oligo(phenylene vinylene) (CdSe-OPV) quantum dot nanostructures using time-tagged, time-resolved (TTTR) photon counting techniques. We find that fluorescence decay times for the quantum dot emitter in these composite systems are at least an order of magnitude shorter than ZnS-capped CdSe quantum dot systems. We show that both the blinking suppression and associated lifetime/count rate behavior can be described by a modified version of the diffusive reaction coordinate model which couples slow fluctuations in quantum dot electron (1Se, 1Pe) energies to Auger-assisted hole trapping processes, hence modifying both blinking statistics and excited-state decay rates. PMID:17655370

Odoi, M Y; Hammer, N I; Early, K T; McCarthy, K D; Tangirala, R; Emrick, T; Barnes, M D

2007-09-01

126

A unified statistical framework for material decomposition using multienergy photon counting x-ray detectors  

SciTech Connect

Purpose: Material decomposition using multienergy photon counting x-ray detectors (PCXD) has been an active research area over the past few years. Even with some success, the problem of optimal energy selection and three material decomposition including malignant tissue is still on going research topic, and more systematic studies are required. This paper aims to address this in a unified statistical framework in a mammographic environment.Methods: A unified statistical framework for energy level optimization and decomposition of three materials is proposed. In particular, an energy level optimization algorithm is derived using the theory of the minimum variance unbiased estimator, and an iterative algorithm is proposed for material composition as well as system parameter estimation under the unified statistical estimation framework. To verify the performance of the proposed algorithm, the authors performed simulation studies as well as real experiments using physical breast phantom and ex vivo breast specimen. Quantitative comparisons using various performance measures were conducted, and qualitative performance evaluations for ex vivo breast specimen were also performed by comparing the ground-truth malignant tissue areas identified by radiologists.Results: Both simulation and real experiments confirmed that the optimized energy bins by the proposed method allow better material decomposition quality. Moreover, for the specimen thickness estimation errors up to 2 mm, the proposed method provides good reconstruction results in both simulation and real ex vivo breast phantom experiments compared to existing methods.Conclusions: The proposed statistical framework of PCXD has been successfully applied for the energy optimization and decomposition of three material in a mammographic environment. Experimental results using the physical breast phantom and ex vivo specimen support the practicality of the proposed algorithm.

Choi, Jiyoung; Kang, Dong-Goo; Kang, Sunghoon; Sung, Younghun [Samsung Advanced Institute of Technology (SAIT), San 14, Nong-seo dong, Giheung-gu, Yongin, Kyunggi 446-712 (Korea, Republic of)] [Samsung Advanced Institute of Technology (SAIT), San 14, Nong-seo dong, Giheung-gu, Yongin, Kyunggi 446-712 (Korea, Republic of); Ye, Jong Chul [Bio-Imaging and Signal Processing Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejon 305-701 (Korea, Republic of)] [Bio-Imaging and Signal Processing Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejon 305-701 (Korea, Republic of)

2013-09-15

127

Statistical Power to Detect the Correct Number of Classes in Latent Profile Analysis  

PubMed Central

Little research has examined factors influencing statistical power to detect the correct number of latent classes using latent profile analysis (LPA). This simulation study examined power related to inter-class distance between latent classes given true number of classes, sample size, and number of indicators. Seven model selection methods were evaluated. None had adequate power to select the correct number of classes with a small (Cohen’s d = .2) or medium (d = .5) degree of separation. With a very large degree of separation (d = 1.5), the Lo-Mendell-Rubin test (LMR), adjusted LMR, bootstrap likelihood-ratio test, BIC, and sample-size adjusted BIC were good at selecting the correct number of classes. However, with a large degree of separation (d = .8), power depended on number of indicators and sample size. The AIC and entropy poorly selected the correct number of classes, regardless of degree of separation, number of indicators, or sample size. PMID:24489457

Coxe, Stefany; Cham, Heining

2012-01-01

128

Thwarting the Photon Number Splitting Attack with Entanglement Enhanced BB84 Quantum Key Distribution  

NASA Astrophysics Data System (ADS)

We develop an improvement to the weak laser pulse BB84 scheme for quantum key distribution, which utilizes entanglement to improve the security of the scheme and enhance its resilience to the photon number splitting attack. This protocol relies on the non-commutation of photon phase and number to detect an eavesdropper performing quantum non-demolition measurement on number. The potential advantages and disadvantages of this scheme are compared to the coherent decoy state solution. Most entanglement based quantum key distribution schemes rely on violations of Bell's inequalities to ensure security. However, this is not the strategy that our entanglement enhanced (EE) BB84 employs here. Instead, we detect Eve by introducing an entangled quantum state into the system that is sensitive to Eve's QND measurements. This allows for a recovery of an approximately linear dependence on transmittivity for the key rate. EE BB84 shares this advantage with coherent decoy state protocols as well as schemes that utilize strong phase reference pulses to eliminate Eve's ability to send Bob vacuum signals.

Richardson, Chris; Sabottke, Carl; Yurtsever, Ulvi; Lamas, Antia; Dowling, Jonathan; Anisimov, Petr

2012-02-01

129

Practical and fast quantum random number generation based on photon arrival time relative to external reference  

SciTech Connect

We present a practical high-speed quantum random number generator, where the timing of single-photon detection relative to an external time reference is measured as the raw data. The bias of the raw data can be substantially reduced compared with the previous realizations. The raw random bit rate of our generator can reach 109 Mbps. We develop a model for the generator and evaluate the min-entropy of the raw data. Toeplitz matrix hashing is applied for randomness extraction, after which the final random bits are able to pass the standard randomness tests.

Nie, You-Qi; Zhang, Jun, E-mail: zhangjun@ustc.edu.cn; Pan, Jian-Wei [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Hong-Fei; Wang, Jian [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Zhen; Ma, Xiongfeng [Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084 (China)

2014-02-03

130

Conservation of the photon number in the generalized nonlinear Schroedinger equation in axially varying optical fibers  

SciTech Connect

We reexamine the derivation of the generalized nonlinear Schroedinger equation in the case of nonaxially uniform optical fibers, taking into account the longitudinal and spectral evolutions of all pertinent linear parameters. Our theory leads to an improved form of this equation that highlights an additional term, which ensures the conservation of the total photon number in nonuniform optical fibers in the absence of attenuation. Numerical simulations confirm the validity of this theory in the context of a Raman-induced soliton self-frequency shift, emission of Cherenkov radiation, and a soliton blue shift.

Vanvincq, O.; Travers, J. C.; Kudlinski, A. [Femtosecond Optics Group, Physics Department, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Universite Lille 1, Laboratoire PhLAM, IRCICA, F-59655 Villeneuve d'Ascq (France)

2011-12-15

131

Practical and fast quantum random number generation based on photon arrival time relative to external reference  

NASA Astrophysics Data System (ADS)

We present a practical high-speed quantum random number generator, where the timing of single-photon detection relative to an external time reference is measured as the raw data. The bias of the raw data can be substantially reduced compared with the previous realizations. The raw random bit rate of our generator can reach 109 Mbps. We develop a model for the generator and evaluate the min-entropy of the raw data. Toeplitz matrix hashing is applied for randomness extraction, after which the final random bits are able to pass the standard randomness tests.

Nie, You-Qi; Zhang, Hong-Fei; Zhang, Zhen; Wang, Jian; Ma, Xiongfeng; Zhang, Jun; Pan, Jian-Wei

2014-02-01

132

Ultralow-noise readout circuit with an avalanche photodiode: toward a photon-number-resolving detector.  

PubMed

The charge-integration readout circuit was fabricated to achieve an ultralow-noise preamplifier for photoelectrons generated in an avalanche photodiode with linear mode operation at 77 K. To reduce the various kinds of noise, the capacitive transimpedance amplifier was used and consisted of low-capacitance circuit elements that were cooled with liquid nitrogen. As a result, the readout noise is equal to 3.0 electrons averaged for a period of 40 ms. We discuss the requirements for avalanche photodiodes to achieve photon-number-resolving detectors below this noise level. PMID:17304297

Tsujino, Kenji; Akiba, Makoto; Sasaki, Masahide

2007-03-01

133

Discrimination of Optical Coherent States using a Photon Number Resolving Detector  

E-print Network

The discrimination of non-orthogonal quantum states with reduced or without errors is a fundamental task in quantum measurement theory. In this work, we investigate a quantum measurement strategy capable of discriminating two coherent states probabilistically with significantly smaller error probabilities than can be obtained using non-probabilistic state discrimination. We find that appropriate postselection of the measurement data of a photon number resolving detector can be used to discriminate two coherent states with small error probability. We compare our new receiver to an optimal intermediate measurement between minimum error discrimination and unambiguous state discrimination.

Christoffer Wittmann; Ulrik L. Andersen; Gerd Leuchs

2009-05-15

134

Intramolecular Distances and Dynamics from the Combined Photon Statistics of Single-Molecule FRET and Photoinduced Electron  

E-print Network

Intramolecular Distances and Dynamics from the Combined Photon Statistics of Single-Molecule FRET resonance energy transfer (FRET) and photo- induced electron transfer (PET) have developed into versatile are frequently used as a donor and acceptor for single-molecule FRET, are also suitable as PET probes

Schuler, Ben

135

OTC Paper Number 24645 GPU-Event-Mechanics Evaluation of Ice Impact Load Statistics  

E-print Network

to field trials data. A related focus for the study is to explore the use of the GPU-Event-Mechanics (GEMOTC Paper Number 24645 GPU-Event-Mechanics Evaluation of Ice Impact Load Statistics Claude Daley Conference This paper was prepared for presentation at the Arctic Technology Conference held in Houston

Peters, Dennis

136

Atmospheric particle number size distribution in central Europe: Statistical relations to air masses and meteorology  

Microsoft Academic Search

Atmospheric particle number size distributions determined over 1.5 years at a central European site were statistically analyzed in terms of their relation to time of day, season, meteorology, and synoptic-scale air masses. All size distributions were decomposed into lognormal particle modes corresponding to the accumulation, Aitken, aged nucleation, and nucleation modes. The concentration of nucleation mode particles (30 nm) lacked

Wolfram Birmili; Alfred Wiedensohler; Jost Heintzenberg; Katrin Lehmann

2001-01-01

137

Statistical independence of a new class of inversive congruential pseudorandom numbers  

SciTech Connect

Linear congruential pseudorandom numbers show several undesirable regularities which can render them useless for certain stochastic simulations. This was the motiviation for important recent developments in nonlinear congruential methods for generating uniform pseudorandom numbers. It is particularly promising to achieve nonlinearity by employing the operation of multiplicative inversion with respect to a prime modulus. In the present paper a new class of such inversive congruential generators is introduced and analyzed. It is shown that they have excellent statistical independence properties and model true random numbers very closely. The methods of proof rely heavily on Weil-Stepanov bounds for rational exponential sums. 39 refs.

Eichenauer-Herrmann, J.

1993-01-01

138

Estimation of laser system pointing performance by use of statistics of return photons.  

PubMed

Strategic laser systems are subject to residual pointing errors arising from vibrations and atmospheric turbulence, estimates of which may allow improved system performance. Field data from the Air Force Research Laboratory Floodbeam Experiments suggested a linear relationship between the mean and standard deviation of the shot-by-shot signals and the jitter. An ideal analytic solution and Monte Carlo simulations confirmed this result for a relatively large number of returns. A refined approach using statistical chi(2) techniques, which simultaneously estimates jitter and boresight, was developed to address results from satellite passes with relatively few returns and provides excellent jitter and boresight predictions. PMID:18338019

Lukesh, G; Chandler, S; Voelz, D

2000-03-20

139

Semiconductor Quantum Dot: A Quantum Light Source of Multicolor Photons with Tunable Statistics  

Microsoft Academic Search

We investigate the intensity correlation properties of single photons emitted from an optically excited single semiconductor quantum dot. The second order temporal coherence function of the photons emitted at various wavelengths is measured as a function of the excitation power. We show experimentally and theoretically that a quantum dot is not only a source of nonclassically correlated monochromatic photons but

D. V. Regelman; U. Mizrahi; D. Gershoni; E. Ehrenfreund; W. V. Schoenfeld; P. M. Petroff

2001-01-01

140

Large-photon-number extraction from individual atoms trapped in an optical lattice  

SciTech Connect

The atom-by-atom characterization of quantum gases requires the development of novel measurement techniques. One particularly promising new technique demonstrated in recent experiments uses strong fluorescent laser scattering from neutral atoms confined in a short-period optical lattice to measure the positions of individual atoms in the sample. A crucial condition for the measurements is that atomic hopping between lattice sites must be strongly suppressed despite substantial photon recoil heating. This paper models three-dimensional polarization gradient cooling of atoms trapped within a far-detuned optical lattice. The atomic dynamics are simulated using a hybrid Monte Carlo and master-equation analysis in order to predict the frequency of processes which give rise to degradation or loss of the fluorescent signal during measurements. It is shown, consistently with the experimental results, that there exists a wide parameter range in which the lifetime of strongly fluorescing isolated lattice-trapped atoms is limited by background gas collisions rather than radiative processes. In these cases the total number of scattered photons can be as large as 10{sup 8} per atom. The performance of the technique is related to relevant experimental parameters.

Shotter, M. D. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom) and National Institute of Standards and Technology, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423 (United States)

2011-03-15

141

Generating arbitrary photon-number entangled states for continuous-variable quantum informatics.  

PubMed

We propose two experimental schemes that can produce an arbitrary photon-number entangled state (PNES) in a finite dimension. This class of entangled states naturally includes non-Gaussian continuous-variable (CV) states that may provide some practical advantages over the Gaussian counterparts (two-mode squeezed states). We particularly compare the entanglement characteristics of the Gaussian and the non-Gaussian states in view of the degree of entanglement and the Einstein-Podolsky-Rosen correlation, and further discuss their applications to the CV teleportation and the nonlocality test. The experimental imperfection due to the on-off photodetectors with nonideal efficiency is also considered in our analysis to show the feasibility of our schemes within existing technologies. PMID:22714485

Lee, Su-Yong; Park, Jiyong; Lee, Hai-Woong; Nha, Hyunchul

2012-06-18

142

Generating arbitrary photon-number entangled states for continuous-variable quantum informatics  

E-print Network

We propose two experimental schemes that can produce an arbitrary photon-number entangled state (PNES) in a finite dimension. This class of entangled states naturally includes non-Gaussian continuous-variable (CV) states that may provide some practical advantages over the Gaussian counterparts (two-mode squeezed states). We particularly compare the entanglement characteristics of the Gaussian and the non-Gaussian states in view of the degree of entanglement and the Einstein-Podolsky-Rosen correlation, and further discuss their applications to the CV teleportation and the nonlocality test. The experimental imperfection due to the on-off photodetectors with nonideal efficiency is also considered in our analysis to show the feasibility of our schemes within existing technologies.

Su-Yong Lee; Jiyong Park; Hai-Woong Lee; Hyunchul Nha

2012-06-13

143

Capacity of the Bosonic Wiretap Channel and the Entropy Photon-Number Inequality  

E-print Network

Determining the ultimate classical information carrying capacity of electromagnetic waves requires quantum-mechanical analysis to properly account for the bosonic nature of these waves. Recent work has established capacity theorems for bosonic single-user and broadcast channels, under the presumption of two minimum output entropy conjectures. Despite considerable accumulated evidence that supports the validity of these conjectures, they have yet to be proven. In this paper, it is shown that the second conjecture suffices to prove the classical capacity of the bosonic wiretap channel, which in turn would also prove the quantum capacity of the lossy bosonic channel. The preceding minimum output entropy conjectures are then shown to be simple consequences of an Entropy Photon-Number Inequality (EPnI), which is a conjectured quantum-mechanical analog of the Entropy Power Inequality (EPI) form classical information theory.

Saikat Guha; Jeffrey H. Shapiro; Baris I. Erkmen

2008-01-06

144

Wideband direction finding using a photonic robust symmetrical number system technique  

NASA Astrophysics Data System (ADS)

Dual electrode Mach-Zehnder modulators (DE-MZMs) are used to conduct phase detection for direct wideband direction finding (DF) of microwave signals. It is demonstrated theoretically and through simulation and experimentation that the normalized magnitude of the output signal phase detector circuit is equal to |sin(?/2)|, where ? is the phase difference between the plane waves arriving at the reference and measurement antennas of a linear DF array. A four-element wideband photonic DF system with robust symmetrical number system preprocessing is presented. Simulation and experimental testing results are provided to demonstrate the theoretical concept. The results demonstrate a direct DF receiver using DE-MZMs that achieves fine angular resolution using a much smaller array size than is typically required for linear arrays employing super-resolution signal processing techniques.

Tedesso, Thomas W.; Calusdian, James; Sewing, Carsten; Pace, Phillip E.

2014-11-01

145

Low-photon-number optical switching with a single quantum dot coupled to a photonic crystal cavity.  

PubMed

We demonstrate fast nonlinear optical switching between two laser pulses with as few as 140 photons of pulse energy by utilizing strong coupling between a single quantum dot (QD) and a photonic crystal cavity. The cavity-QD coupling is modified by a detuned pump pulse, resulting in a modulation of the scattered and transmitted amplitude of a time synchronized probe pulse that is resonant with the QD. The temporal switching response is measured to be as fast as 120 ps, demonstrating the ability to perform optical switching on picosecond timescales. PMID:23003653

Bose, Ranojoy; Sridharan, Deepak; Kim, Hyochul; Solomon, Glenn S; Waks, Edo

2012-06-01

146

Photon-number squeezing with a noisy femtosecond fiber laser amplifier source using a collinear balanced detection technique.  

PubMed

We experimentally demonstrate photon-number squeezing at 1.55 ?m using a noisy erbium-doped fiber amplifier (EDFA). We employ a collinear balanced detection (CBD) technique, where the intensity noise at a specific radio frequency is canceled between two pulse trains. In spite of substantially large excess noise (>10 dB) in an EDFA due to amplified spontaneous emission, we successfully cancel the intensity noise and achieve a shot noise limit at a specific radio frequency with the CBD technique. We exploit two sets of fiber polarization interferometers to generate squeezed light and observe a maximal photon-number squeezing of -2.6 dB. PMID:24150352

Sawai, Shota; Kawauchi, Hikaru; Hirosawa, Kenichi; Kannari, Fumihiko

2013-10-21

147

Photon Number-Phase Uncertainty Relation in the Evolution of the Field in a Kerr-Like Medium  

NASA Technical Reports Server (NTRS)

A model of a single-mode field, initially prepared in a coherent state, coupled to a two-level atom surrounded by a nonlinear Kerr-like medium contained inside a very good quality cavity is considered. We derive the photon number-phase uncertainty relation in the evolution of the field for a weak and strong nonlinear coupling respectively, within the Hermitian phase operator formalism of Pegg and Barnett, and discuss the effects of nonlinear coupling of the Kerr-like medium on photon number-phase uncertainty relation of the field.

Fan, An-Fu; Sun, Nian-Chun

1996-01-01

148

Quantum fingerprinting with coherent states and a constant mean number of photons  

NASA Astrophysics Data System (ADS)

We present a protocol for quantum fingerprinting that is ready to be implemented with current technology and is robust to experimental errors. The basis of our scheme is an implementation of the signal states in terms of a coherent state in a superposition of time-bin modes. Experimentally, this requires only the ability to prepare coherent states of low amplitude and to interfere them in a balanced beam splitter. The states used in the protocol are arbitrarily close in trace distance to states of O (log2n) qubits, thus exhibiting an exponential separation in abstract communication complexity compared to the classical case. The protocol uses a number of optical modes that is proportional to the size n of the input bit strings but a total mean photon number that is constant and independent of n. Given the expended resources, our protocol achieves a task that is provably impossible using classical communication only. In fact, even in the presence of realistic experimental errors and loss, we show that there exist a large range of input sizes for which our quantum protocol transmits an amount of information that can be more than two orders of magnitude smaller than a classical fingerprinting protocol.

Arrazola, Juan Miguel; Lütkenhaus, Norbert

2014-06-01

149

Quantum Fingerprinting with Coherent States and a Constant Mean Number of Photons  

E-print Network

We present a protocol for quantum fingerprinting that is ready to be implemented with current technology and is robust to experimental errors. The basis of our scheme is an implementation of the signal states in terms of a coherent state in a superposition of time-bin modes. Experimentally, this requires only the ability to prepare coherent states of low amplitude, and to interfere them in a balanced beam splitter. The states used in the protocol are arbitrarily close in trace distance to states of $\\mathcal{O}(\\log_2 n)$ qubits, thus exhibiting an exponential separation in communication complexity compared to the classical case. The protocol uses a number of optical modes that is proportional to the size $n$ of the input bit-strings, but a total mean photon number that is constant and independent of $n$. Given the expended resources, our protocol achieves a task that is provably impossible using classical communication only. In fact, even in the presence of realistic experimental errors and loss, we show that there exist a large range of input sizes for which our quantum protocol requires communication that can be more than two orders of magnitude smaller than a classical fingerprinting protocol.

Juan Miguel Arrazola; Norbert Lütkenhaus

2014-06-17

150

TEGS-CN: A Statistical Method for Pathway Analysis of Genome-wide Copy Number Profile  

PubMed Central

The effects of copy number alterations make up a significant part of the tumor genome profile, but pathway analyses of these alterations are still not well established. We proposed a novel method to analyze multiple copy numbers of genes within a pathway, termed Test for the Effect of a Gene Set with Copy Number data (TEGS-CN). TEGS-CN was adapted from TEGS, a method that we previously developed for gene expression data using a variance component score test. With additional development, we extend the method to analyze DNA copy number data, accounting for different sizes and thus various numbers of copy number probes in genes. The test statistic follows a mixture of X2 distributions that can be obtained using permutation with scaled X2 approximation. We conducted simulation studies to evaluate the size and the power of TEGS-CN and to compare its performance with TEGS. We analyzed a genome-wide copy number data from 264 patients of non-small-cell lung cancer. With the Molecular Signatures Database (MSigDB) pathway database, the genome-wide copy number data can be classified into 1814 biological pathways or gene sets. We investigated associations of the copy number profile of the 1814 gene sets with pack-years of cigarette smoking. Our analysis revealed five pathways with significant P values after Bonferroni adjustment (<2.8 × 10?5), including the PTEN pathway (7.8 × 10?7), the gene set up-regulated under heat shock (3.6 × 10?6), the gene sets involved in the immune profile for rejection of kidney transplantation (9.2 × 10?6) and for transcriptional control of leukocytes (2.2 × 10?5), and the ganglioside biosynthesis pathway (2.7 × 10?5). In conclusion, we present a new method for pathway analyses of copy number data, and causal mechanisms of the five pathways require further study. PMID:25452685

Huang, Yen-Tsung; Hsu, Thomas; Christiani, David C

2014-01-01

151

Statistical Study on Personal Reduction Coefficients of Sunspot Numbers Since 1981  

NASA Astrophysics Data System (ADS)

Using sunspot number data from 270 historical stations for the period 1981-2013, we investigate their personal reduction coefficients ($) statistically. Chang & Oh (2012) perform a simulation showing that the k varies with the solar cycle. We try to verify their results using observational data. For this, a weighted mean and weighted standard deviation of monthly sunspot number are used to estimate the error from observed data. We find that the observed error (noise) is much smaller than that used in the simulation. Thus no distinct k-variation with the solar cycle is observed contrary to the simulation. In addition, the probability distribution of k is determined to be non-Gaussian with a fat-tail on the right side. This result implies that the relative sunspot number after 1981 might be overestimated since the mean value of k is less than that of the Gaussian distribution.

Cho, Il-Hyun; Bong, Su-Chan; Cho, Kyung-Suk; Lee, Jaejin; Kim, Rok-Soon; Park, Young-Deuk; Kim, Yeon-Han

2014-12-01

152

Volume 209, number 1,2 CHEMICAL PHYSICS LETTERS 25 June 1993 Femtosecond two-photon ionization spectroscopy  

E-print Network

-photon ionization (TPI) spectroscopy [41 and by depletion spectroscopy [ 51. In the case of larger sodium clusters the TPI spectroscopy with nanose- cond lasers fails due to the very short lifetimes (0.33- 3.5 ps;Volume 209, number I,2 CHEMICAL PHYSICS LETTERS 25 June 1993 [12] showed that the TPI spectrum

Kassel, Universität

153

Volume 0 (1981), Number 0 pp. 114 COMPUTER GRAPHICS forum A Visualisation Tool used to Develop New Photon Mapping  

E-print Network

Volume 0 (1981), Number 0 pp. 1­14 COMPUTER GRAPHICS forum A Visualisation Tool used to Develop New Photon Mapping Techniques B. Spencer1, M. W. Jones1 and I. S. Lim2 1 Visual and Interactive Computing framework. 1. Introduction Computer graphics research has focused on the development of ever more complete

Jones, Mark W.

154

Statistics of the cosmic Mach number from numerical simulations of a cold dark matter universe  

NASA Technical Reports Server (NTRS)

Results are presented of an analysis of the cosmic Mach number, M, the ratio of the streaming velocity, v, to the random velocity dispersion, sigma, of galaxies in a given patch of the universe, which was performed on the basis of hydrodynamical simulations of the cold dark matter scenario. Galaxy formation is modeled by application of detailed physical processes rather than by the ad hoc assumption of 'bias' between dark matter and galaxy fluctuations. The correlation between M and sigma is found to be very weak for both components. No evidence is found for a physical 'velocity bias' in the quantities which appear in the definition of M. Standard cold-dark-matter-dominated universes are in conflict, at a statistically significant level, with the available observation, in that they predict a Mach number considerably lower than is observed.

Suto, Yasushi; Cen, Renyue; Ostriker, Jeremiah P.

1992-01-01

155

Light statistics by non-calibrated linear photodetectors  

E-print Network

We theoretically demonstrate that detectors endowed with internal gain and operated in regimes in which they do not necessarily behave as photon-counters, but still ensure linear input/output responses, can allow a self-consistent characterization of the statistics of the number of detected photons without need of knowing their gain. We present experiments performed with a photo-emissive hybrid detector on a number of classical fields endowed with non-trivial statistics and show that the method works for both microscopic and mesoscopic photon numbers. The obtained detected-photon probability distributions agree with those expected for the photon numbers, which are also reconstructed by an independent method.

Maria Bondani; Alessia Allevi; Alessandra Andreoni

2008-10-22

156

A model independent lower limit on the number of Gamma Ray Burst hosts from repeater statistics  

E-print Network

We present a general statistical analysis of Gamma Ray Bursts embedded in a host population. If no host generates more than one observed burst, then we show that there is a model independent lower bound on the number of hosts, $H$, of the form $H > c B^2$, where B is the number of observed bursts, and $c$ is a constant of order one which depends on the confidence level (CL) attached to the bound. An analysis by Tegmark et al. (1996) shows that the BATSE 3B catalog of 1122 bursts is consistent with no repeaters being present, and assuming that this is indeed the case, our result implies a host population with at least H=1.2x10^6 members. Without the explicit assumption of no repeaters, a Bayesian analysis based on the results of Tegmark et al. (1996) can be performed which gives the weaker bound of $H>1.7\\times 10^5$ at the 90% CL. In the light of the non-detection of identifiable hosts in the small error-boxes associated with transient counterparts to GRBs, this result gives a model independent lower bound to the number of any rare or exotic hosts. If in fact GRBs are found to be associated with a particular sub-class of galaxies, then an analysis along the lines presented here can be used to place a lower bound on the fraction of galaxies in this sub-class. Another possibility is to treat galaxy clusters (rather than individual galaxies) as the host population, provided that the angular size of each cluster considered is less than the resolution of the detector. Finally, if repeaters are ever detected in a statistically significant manner, this analysis can be readily adapted to find upper and lower limits on $H$.

Anupam Singh; Mark Srednicki

1997-05-23

157

Statistical properties of coherent photon-subtracted two-mode squeezed vacuum and its application in quantum teleportation  

NASA Astrophysics Data System (ADS)

We introduce a kind of non-Gaussian entangled state, which can be obtained by operating a non-local coherent photon-subtraction operation on a two-mode squeezed vacuum. It is found that its normalization factor is only related to the Legendre polynomials, which is a compact expression. Its statistical properties are discussed by the negative region Wigner function with the analytical expression. As an application, the quantum teleportation for coherent states is considered by using the non-Gaussian state as an entangled channel. It is found that the teleportation fidelity can be enhanced by this non-Gaussian operation.

Zhang, Guo-Ping; Zheng, Kai-Min; Liu, Shi-You; Hu, Li-Yun

2014-05-01

158

Photon-photon collisions  

SciTech Connect

Studies of photon-photon collisions are reviewed with particular emphasis on new results reported to this conference. These include results on light meson spectroscopy and deep inelastic e..gamma.. scattering. Considerable work has now been accumulated on resonance production by ..gamma gamma.. collisions. Preliminary high statistics studies of the photon structure function F/sub 2//sup ..gamma../(x,Q/sup 2/) are given and comments are made on the problems that remain to be solved.

Burke, D.L.

1982-10-01

159

Statistical analyses of the magnet data for the Advanced Photon Source storage ring magnets  

Microsoft Academic Search

The statistics of the measured magnetic data of 80 dipole, 400 quadrupole, and 280 sextupole magnets of conventional resistive designs for the APS storage ring is summarized. In order to accommodate the vacuum chamber, the curved dipole has a C-type cross section and the quadrupole and sextupole cross sections have 180? and 120? symmetries, respectively. The data statistics include the

S. H. Kim; D. W. Carnegie; C. Doose; R. Hogrefe; K. Kim; R. Merl

1996-01-01

160

Coherence holography and photon-correlation holography: marriage between holography and statistical optics  

NASA Astrophysics Data System (ADS)

We review two techniques of unconventional holography, coherence holography and photon-correlation holography, which we recently proposed and experimentally demonstrated. We will emphasize the importance of noticing mathematical analogies in optics and physical phenomena, which give insights into the methodology for developing new techniques.

Takeda, Mitsuo; Wang, Wei; Naik, Dinesh N.

2011-10-01

161

The statistical single-photon technique in physical-optic experiments  

Microsoft Academic Search

The principles underlying the time-correlated single-photon technique are discussed. An analysis is then presented of the characteristic errors of this technique for various experimental conditions, differing in regard to the character and type of input fluxes and their intensities. Particular attention is given to the application of this technique in the stochastic excitation of radio luminescence. Ways to enhance the

M. I. Demchuk; M. A. Ivanov

1981-01-01

162

Proof-of-principle experiment of a modified photon-number-splitting attack against quantum key distribution  

SciTech Connect

Any imperfections in a practical quantum key distribution (QKD) system may be exploited by an eavesdropper to collect information about the key without being discovered. We propose a modified photon-number-splitting attack scheme against QKD systems based on weak laser pulses taking advantage of possible multiphoton pulses. Proof-of-principle experiments are demonstrated. The results show that the eavesdropper can get information about the key generated between the legitimate parties without being detected. Since the equivalent attenuation introduced by the eavesdropper for pulses of different average photon numbers are different, the decoy-state method is effective in fighting against this kind of attack. This has also been proven in our experiments.

Liu Weitao; Sun Shihai; Liang Linmei; Yuan Jianmin [Department of Physics, College of Science, National University of Defense Technology, Changsha, 410073 (China)

2011-04-15

163

Effects of Lewis number on conditional fluid velocity statistics in low Damköhler number turbulent premixed combustion: A direct numerical simulation analysis  

NASA Astrophysics Data System (ADS)

The effects of global Lewis number Le on the statistics of fluid velocity components conditional in unburned reactants and fully burned products in the context of Reynolds Averaged Navier Stokes simulations have been analysed using a Direct Numerical Simulations (DNS) database of statistically planar turbulent premixed flames with a low Damköhler number and Lewis number ranging from 0.34 to 1.2. The conditional velocity statistics extracted from DNS data have been analysed with respect to the well-known Bray-Moss-Libby (BML) expressions which were derived based on bi-modal probability density function of reaction progress variable for high Damköhler number flames. It has been shown that the Lewis number substantially affects the mean velocity and the velocity fluctuation correlation conditional in products, with the effect being particularly pronounced for low Le. As far as the mean velocity and the velocity fluctuation correlation conditional in reactants are concerned, the BML expressions agree reasonably well with the DNS data reported in the present work. Based on a priori analysis of present and previously reported DNS data, the BML expressions have been empirically modified here in order to account for Lewis number effects, and the non-bimodal distribution of reaction progress variable. Moreover, it has been demonstrated for the first time that surface averaged velocity components and Reynolds stresses conditional in unburned reactants can be modelled without invoking expressions involving the Lewis number, as these surface averaged conditional quantities remain approximately equal to their conditionally averaged counterparts in the unburned mixture.

Chakraborty, Nilanjan; Lipatnikov, Andrei N.

2013-04-01

164

Statistical analyses of the magnet data for the advanced photon source storage ring magnets  

SciTech Connect

The statistics of the measured magnetic data of 80 dipole, 400 quadrupole, and 280 sextupole magnets of conventional resistive designs for the APS storage ring is summarized. In order to accommodate the vacuum chamber, the curved dipole has a C-type cross section and the quadrupole and sextupole cross sections have 180{degrees} and 120{degrees} symmetries, respectively. The data statistics include the integrated main fields, multipole coefficients, magnetic and mechanical axes, and roll angles of the main fields. The average and rms values of the measured magnet data meet the storage ring requirements.

Kim, S.H.; Carnegie, D.W.; Doose, C.; Hogrefe, R.; Kim, K.; Merl, R.

1995-05-01

165

Solar light trapping in slanted conical-pore photonic crystals: Beyond statistical ray trapping  

E-print Network

in real-time. To achieve high solar power conversion efficiency, one need to use advanced materialsn2 statistical ray trapping." These results suggest silicon solar cell efficiencies exceeding 20. With the exception of nuclear energy, nearly all other sources of power in use today are derivatives of solar power

John, Sajeev

166

Photon statistics in blinking fluorescence of single PPV-PPyV molecule  

NASA Astrophysics Data System (ADS)

A theoretical six-level model for blinking fluorescence of single PPV-PPyV copolymer molecule excited by CW-laser light is proposed. The model has been chosen in accordance with the following facts found in the Paul Barbara group experiment: (i) alternation of two types of fluorescence with moderate and strong levels of emission, (ii) existence of "dark" states with no fluorescence, (iii) linear dependence of inverse on-interval duration on laser intensity, and (iv) existence of laser intensity independent off-intervals. Relations between the distribution function w''(N, T) for photons emitted by a single molecule, the distribution function w'(N, T) for photons arriving at photomultiplier tube (PMT) and photo-electric pulse distribution w(N, T) created in a PMT are discussed. The theory is able to describe pulse distribution function w(N, T) measured experimentally at signal acquisition time T = 0.1 s. Values of all rate constants of the model have been found from comparison of the theory with the experiment. Distributions won, off(t) of on- and off-times and distribution w(N, T) of pulses have been calculated for infrequent and frequent inter-conformational jumps in single copolymer molecule.

Fedyanin, V. V.; Osad'ko, I. S.

2011-09-01

167

Calculation and analysis of the number of return photons from sodium laser beacon excited by the long pulse laser with circular polarization  

NASA Astrophysics Data System (ADS)

The number of return photons from sodium laser beacon (SLB) greatly suffers down-pumping, recoil, and geomagnetic field when the long pulse laser with circular polarization interacts with sodium atoms in the mesosphere. Considering recoil and down-pumping effects on the number of return photons from SLB, the spontaneous radiation rates are obtained by numerical computations and fittings. Furthermore, combining with the geomagnetic field effects, a new expression is achieved for calculating the number of return photons. By using this expression and considering the stochastic distribution of laser intensity in the mesosphere under different turbulence models for atmosphere, the number of return photons excited by the narrow-band single mode laser and that by the narrow-band three-mode laser are respectively calculated. The results show that the narrow-band three-mode laser with a specific spectrum structure has a higher spontaneous radiation rate and more return photons than a narrow-band single mode laser. Of note, the effect of the atmospheric turbulence on the number of return photons is remarkable. Calculation results indicate that the number of return photons under the HV5/7 model for atmospheric turbulence is much higher than that under the Greenwood and ModHV models.

Liu, Xiang-Yuan; Qian, Xian-Mei; Li, Yu-Jie; Rao, Rui-Zhong

2014-12-01

168

Statistical measurements of quantum emitters coupled to Anderson-localized modes in disordered photonic-crystal waveguides  

E-print Network

Optical nanostructures have proven to be meritorious for tailoring the emission properties of quantum emitters. However, unavoidable fabrication imperfections may represent a nuisance. Quite remarkably, disorder offers new opportunities since light can be efficiently confined by random multiple scattering leading to Anderson localization. Here we investigate the effect of such disorder-induced cavities on the emission dynamics of single quantum dots embedded in disordered photonic-crystal waveguides. We present time-resolved measurements of both the total emission from Anderson-localized cavities and from single emitters that are coupled to the cavities. We observe both strongly inhibited and enhanced decay rates relative to the rate of spontaneous emission in a homogeneous medium. From a statistical analysis, we report an average Purcell factor of 2 in without any control on the quantum dot - cavity detuning. By spectrally tuning individual quantum dots into resonance with Anderson-localized modes, a maximum...

Javadi, Alisa; Sapienza, Luca; Thyrrestrup, Henri; Lodahl, Peter

2013-01-01

169

Paper Number: 300494 History of Science and Statistical Education: Examples from Fisherian and Pearsonian schools  

E-print Network

/philosophy of science. This article will discuss how statistical methods developed by Karl Pearson and R. A. Fisher and Neyman/E .S. Pearson, son of Karl Pearson, respectively. Students will appreciate the meanings and Karl Pearson are considered the two most important figures in statistics as well as influential

Yu, Alex

170

Extending OPNET Modeler with External Pseudo Random Number Generators and Statistical Evaluation by the Limited Relative Error Algorithm  

NASA Astrophysics Data System (ADS)

Pseudo Random Number Generators (PRNG) are the base for stochastic simulations. The usage of good generators is essential for valid simulation results. OPNET Modeler a well-known tool for simulation of communication networks provides a Pseudo Random Number Generator. The extension of OPNET Modeler with external generators and additional statistical evaluation methods that has been performed for this paper increases the flexibility and options in the simulation studies performed.

Becker, Markus; Weerawardane, Thushara Lanka; Li, Xi; Görg, Carmelita

171

A Statistical Change Point Model Approach for the Detection of DNA Copy Number Variations in Array CGH Data  

Microsoft Academic Search

Array comparative genomic hybridization (aCGH) provides a high-resolution and high-throughput technique for screening of copy number variations (CNVs) within the entire genome. This technique, compared to the conventional CGH, significantly improves the identification of chromosomal abnormalities. However, due to the random noise inherited in the imaging and hybridization process, identifying statistically significant DNA copy number changes in aCGH data is

Jie Chen; Yu-Ping Wang

2009-01-01

172

Generic Two-Qubit Photonic Gates Implemented by Number-Resolving Photodetection  

E-print Network

We combine numerical optimization techniques [Uskov et al., Phys. Rev. A 79, 042326 (2009)] with symmetries of the Weyl chamber to obtain optimal implementations of generic linear-optical KLM-type two-qubit entangling gates. We find that while any two-qubit controlled-U gate, including CNOT and CS, can be implemented using only two ancilla resources with success probability S > 0.05, a generic SU(4) operation requires three unentangled ancilla photons, with success S > 0.0063. Specifically, we obtain a maximal success probability close to 0.0072 for the B gate. We show that single-shot implementation of a generic SU(4) gate offers more than an order of magnitude increase in the success probability and two-fold reduction in overhead ancilla resources compared to standard triple-CNOT and double-B gate decompositions.

Dmitry B. Uskov; A. Matthew Smith; Lev Kaplan

2009-08-18

173

Super-Poissonian Statistics of Photon Emission from Single CdSe-CdS Core-Shell Nanocrystals Coupled to Metal Nanostructures  

NASA Astrophysics Data System (ADS)

We demonstrate that photon antibunching observed for individual nanocrystal quantum dots (NQDs) can be transformed into photon bunching characterized by super-Poissonian statistics when they are coupled to metal nanostructures (MNs). This observation indicates that, while the quantum yield of a biexciton (Q2X) is lower than that of a single exciton (Q1X) in freestanding NQDs, Q2X becomes greater than Q1X in NQDs coupled to MNs. This unique phenomenon is attributed to metal-induced quenching with a rate that scales more slowly with exciton multiplicity than the radiative decay rate and dominates over other nonradiative decay channels for both single excitons and biexcitons.

Park, Young-Shin; Ghosh, Yagnaseni; Chen, Yongfen; Piryatinski, Andrei; Xu, Ping; Mack, Nathan H.; Wang, Hsing-Lin; Klimov, Victor I.; Hollingsworth, Jennifer. A.; Htoon, Han

2013-03-01

174

The Incidence of Traumatic Brain Injury in the United States. Disability Statistics Abstract, Number 14.  

ERIC Educational Resources Information Center

This abstract summarizes recent statistics on the prevalence and causes of traumatic brain injuries (TBI), the populations it affects, and the degree of disability it causes. Estimates are based on 1985-1987 data from the National Health Interview Survey, a household survey of the noninstitutionalized U.S. population. Analysis indicates: the…

Forkosch, Joel Anton; And Others

175

Static Numbers to Dynamic Statistics: Designing a Policy-Friendly Social Policy Indicator Framework  

ERIC Educational Resources Information Center

In line with the economic crisis and rapid socio-demographic changes, the interest in "social" and "well-being" indicators has been revived. Social indicator movements of the 1960s resulted in the establishment of social indicator statistical frameworks; that legacy has remained intact in many national governments and international organisations.…

Ahn, Sang-Hoon; Choi, Young Jun; Kim, Young-Mi

2012-01-01

176

Statistical measurements of quantum emitters coupled to Anderson-localized modes in disordered photonic-crystal waveguides  

E-print Network

Optical nanostructures have proven to be meritorious for tailoring the emission properties of quantum emitters. However, unavoidable fabrication imperfections may represent a nuisance. Quite remarkably, disorder offers new opportunities since light can be efficiently confined by random multiple scattering leading to Anderson localization. Here we investigate the effect of such disorder-induced cavities on the emission dynamics of single quantum dots embedded in disordered photonic-crystal waveguides. We present time-resolved measurements of both the total emission from Anderson-localized cavities and from single emitters that are coupled to the cavities. We observe both strongly inhibited and enhanced decay rates relative to the rate of spontaneous emission in a homogeneous medium. From a statistical analysis, we report an average Purcell factor of 2 in without any control on the quantum dot - cavity detuning. By spectrally tuning individual quantum dots into resonance with Anderson-localized modes, a maximum Purcell factor of 23.8 is recorded, which lies at the onset of the strong coupling regime. The presented data quantify the potential of naturally occurring Anderson-localized cavities for controlling and enhancing the light-matter interaction strength, which is of relevance not only for cavity quantum-electrodynamics experiments but potentially also for efficient energy harvesting and controllable random lasing.

Alisa Javadi; Pedro D. Garcia; Luca Sapienza; Henri Thyrrestrup; Peter Lodahl

2013-01-02

177

Photon-number-splitting versus cloning attacks in practical implementations of the Bennett-Brassard 1984 protocol for quantum cryptography  

NASA Astrophysics Data System (ADS)

In practical quantum cryptography, the source sometimes produces multiphoton pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Lütkenhaus [Phys. Rev. A 69, 042321 (2004)] that the PNS attack is not always the optimal attack when two photons are present: if errors are present in the correlations Alice-Bob and if Eve cannot modify Bob’s detection efficiency, Eve gains a larger amount of information using another attack based on a 2?3 cloning machine. In this work, we extend this analysis to all distances Alice-Bob. We identify a new incoherent 2?3 cloning attack which performs better than those described before. Using it, we confirm that, in the presence of errors, Eve’s better strategy uses 2?3 cloning attacks instead of the PNS. However, this improvement is very small for the implementations of the Bennett-Brassard 1984 (BB84) protocol. Thus, the existence of these new attacks is conceptually interesting but basically does not change the value of the security parameters of BB84. The main results are valid both for Poissonian and sub-Poissonian sources.

Niederberger, Armand; Scarani, Valerio; Gisin, Nicolas

2005-04-01

178

Photon and carbon ion irradiation of a rat prostate carcinoma: does a higher fraction number increase the metastatic rate?  

PubMed

In a recent published study, we investigated the response of an experimental prostate carcinoma (R3327-AT1) after irradiation with 1, 2 or 6 fractions of carbon ions or photons, respectively. The original intention of this study was to measure the dose-dependent local control probability as well as the related relative biological effectiveness of carbon ions. However, we now report an increased metastatic rate when the number of fractions was increased from 2 to 6. In a total of 246 animals, the actuarial metastatic rates for 1, 2 and 6 fractions were 5.1 ± 3.5%, 5.7 ± 4.0% and 15.3 ± 7.1% for photons and 9.8 ± 7.5%, 4.0 ± 3.9% and 20.3 ± 6.5% for carbon ions, respectively. The increase was significant only for carbon ions (6 vs. 2 fractions,P = 0.03). Although the original experiment was not designed to investigate metastatic rates, this observation may be of general interest to researchers studying radiation-modulated metastatic activity. PMID:24844648

Karger, Christian P; Scholz, Michael; Huber, Peter E; Debus, Jürgen; Peschke, Peter

2014-06-01

179

Photon-number-splitting versus cloning attacks in practical implementations of the Bennett-Brassard 1984 protocol for quantum cryptography  

SciTech Connect

In practical quantum cryptography, the source sometimes produces multiphoton pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Luetkenhaus [Phys. Rev. A 69, 042321 (2004)] that the PNS attack is not always the optimal attack when two photons are present: if errors are present in the correlations Alice-Bob and if Eve cannot modify Bob's detection efficiency, Eve gains a larger amount of information using another attack based on a 2{yields}3 cloning machine. In this work, we extend this analysis to all distances Alice-Bob. We identify a new incoherent 2{yields}3 cloning attack which performs better than those described before. Using it, we confirm that, in the presence of errors, Eve's better strategy uses 2{yields}3 cloning attacks instead of the PNS. However, this improvement is very small for the implementations of the Bennett-Brassard 1984 (BB84) protocol. Thus, the existence of these new attacks is conceptually interesting but basically does not change the value of the security parameters of BB84. The main results are valid both for Poissonian and sub-Poissonian sources.

Niederberger, Armand [Section de Physique, Ecole Polytechinque Federale de Lausanne, CH-1015 Ecublens (Switzerland); Scarani, Valerio; Gisin, Nicolas [Group of Applied Physics, University of Geneva, 20, rue de l'Ecole-de-Medecine, CH-1211 Geneva 4 (Switzerland)

2005-04-01

180

Superradiance, Berry phase, photon phase diffusion, and number squeezed state in the U(1) Dicke (Tavis-Cummings) model  

SciTech Connect

Recently, strong-coupling regimes of superconducting qubits or quantum dots inside a microwave circuit cavity and BEC atoms inside an optical cavity were achieved experimentally. The strong-coupling regimes in these systems were described by the Dicke model. Here, we solve the Dicke model by a 1/N expansion. In the normal state, we find a {radical}(N) behavior of the collective Rabi splitting. In the superradiant phase, we identify an important Berry phase term that has dramatic effects on both the ground state and the excitation spectra of the strongly interacting system. The single photon excitation spectrum has a low-energy quantum phase diffusion mode in imaginary time with a large spectral weight and also a high-energy optical mode with a low spectral weight. The photons are in a number squeezed state that may have wide applications in high sensitive measurements and quantum-information processing. Comparisons with exact diagonalization studies are made. Possible experimental schemes to realize the superradiant phase are briefly discussed.

Ye Jinwu [Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762 (United States); Zhang Cunlin [Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China)

2011-08-15

181

Turbulence statistics in fully developed channel flow at low Reynolds number  

Microsoft Academic Search

A direct numerical simulation of a turbulent channel flow is performed. The unsteady Navier-Stokes equations are solved numerically at a Reynolds number of 3300, based on the mean centerline velocity and channel half-width, with about 4 million grid points. All essential turbulence scales are resolved on the computational grid and no subgrid model is used. A large number of turbulence

John Kim; Parviz Moin; Robert Moser

1987-01-01

182

The increasing number of surgical procedures for female genital fistula in England: Analysis of Hospital Episode Statistics (HES) data.  

PubMed

Abstract The aim of this study was to describe the number and trend of surgical procedures for female genital fistula in England. An online search of Hospital Episode Statistics (HES) data was carried out. Data were available for the 4-year period from 2002-03 until 2005-06. The total number of surgical procedures carried out for female genital fistula steadily increased by 28.7% from 616 in 2002-03 to 793 in 2005-06. The number of surgical procedures performed for rectovaginal fistula exceeded the total number of surgical procedures carried out for vesicovaginal and urethrovaginal fistula in each year of the study period. This pattern needs to be monitored and investigated further. PMID:25020114

Ismail, S I M F

2015-01-01

183

Numbers  

NSDL National Science Digital Library

The purpose of this video tutorial is to review a couple ways in which we think about numbers. Thinking in terms of street numbers, money in bank accounts, and quantum particles (e.g. Bose-Einstein condensate) is contrasted with focusing on associating numbers with distinguishable manipulatives, as is more familiar in K-8 courses. This video concludes with a reminder that the symbol "infinity" is not, itself, a number.

2013-06-14

184

Statistical Estimation of the Gasoline Octane Number Requirement of New Model Automobiles  

Microsoft Academic Search

A new method is proposed for estimating the octane number of gasoline required by new model automobiles. Tests of the assumptions underlying the method, and an illustration of its application, are given.

Claude S. Brinegar; Ronald R. Miller

1960-01-01

185

Numbers  

NSDL National Science Digital Library

This engaging web site contains information and interactive applets related to various number systems: Egyptian, Babylonian, Chinese, Greek, Roman, Mayan, and Arabic. Users learn the history and structure of each system as well as how to count and write numbers. The site also allows users to explore finger systems, calculating machines, other number bases, and "interesting numbers." A series of pages on data and graphs includes information and activities on gathering, analyzing, graphing and sorting data. (Because the section on the Arabic number system is so extensive, it is cataloged separately as a related resource.)

Edkins, Jo

2006-01-01

186

Calculating Confidence, Uncertainty, and Numbers of Samples When Using Statistical Sampling Approaches to Characterize and Clear Contaminated Areas  

SciTech Connect

This report discusses the methodology, formulas, and inputs needed to make characterization and clearance decisions for Bacillus anthracis-contaminated and uncontaminated (or decontaminated) areas using a statistical sampling approach. Specifically, the report includes the methods and formulas for calculating the • number of samples required to achieve a specified confidence in characterization and clearance decisions • confidence in making characterization and clearance decisions for a specified number of samples for two common statistically based environmental sampling approaches. In particular, the report addresses an issue raised by the Government Accountability Office by providing methods and formulas to calculate the confidence that a decision area is uncontaminated (or successfully decontaminated) if all samples collected according to a statistical sampling approach have negative results. Key to addressing this topic is the probability that an individual sample result is a false negative, which is commonly referred to as the false negative rate (FNR). The two statistical sampling approaches currently discussed in this report are 1) hotspot sampling to detect small isolated contaminated locations during the characterization phase, and 2) combined judgment and random (CJR) sampling during the clearance phase. Typically if contamination is widely distributed in a decision area, it will be detectable via judgment sampling during the characterization phrase. Hotspot sampling is appropriate for characterization situations where contamination is not widely distributed and may not be detected by judgment sampling. CJR sampling is appropriate during the clearance phase when it is desired to augment judgment samples with statistical (random) samples. The hotspot and CJR statistical sampling approaches are discussed in the report for four situations: 1. qualitative data (detect and non-detect) when the FNR = 0 or when using statistical sampling methods that account for FNR > 0 2. qualitative data when the FNR > 0 but statistical sampling methods are used that assume the FNR = 0 3. quantitative data (e.g., contaminant concentrations expressed as CFU/cm2) when the FNR = 0 or when using statistical sampling methods that account for FNR > 0 4. quantitative data when the FNR > 0 but statistical sampling methods are used that assume the FNR = 0. For Situation 2, the hotspot sampling approach provides for stating with Z% confidence that a hotspot of specified shape and size with detectable contamination will be found. Also for Situation 2, the CJR approach provides for stating with X% confidence that at least Y% of the decision area does not contain detectable contamination. Forms of these statements for the other three situations are discussed in Section 2.2. Statistical methods that account for FNR > 0 currently only exist for the hotspot sampling approach with qualitative data (or quantitative data converted to qualitative data). This report documents the current status of methods and formulas for the hotspot and CJR sampling approaches. Limitations of these methods are identified. Extensions of the methods that are applicable when FNR = 0 to account for FNR > 0, or to address other limitations, will be documented in future revisions of this report if future funding supports the development of such extensions. For quantitative data, this report also presents statistical methods and formulas for 1. quantifying the uncertainty in measured sample results 2. estimating the true surface concentration corresponding to a surface sample 3. quantifying the uncertainty of the estimate of the true surface concentration. All of the methods and formulas discussed in the report were applied to example situations to illustrate application of the methods and interpretation of the results.

Piepel, Gregory F.; Matzke, Brett D.; Sego, Landon H.; Amidan, Brett G.

2013-04-27

187

Number of minerals of various chemical elements: Statistics 2012 (a new approach to an old problem)  

NASA Astrophysics Data System (ADS)

A list of all mineral species (4809) approved by IMA to 2012 inclusive has been compiled. The crystal chemical formulae of these minerals has been reviewed; each mineral species is marked by a set of the n-component chemical system (where n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10). The leading chemical elements by number of mineral species in the Earth's crust are as follows (number of mineral species is in parentheses): oxygen (3929), hydrogen (2700), silicon (1420), calcium (1130), sulfur (978), aluminum (959), iron (920), sodium (850), copper (588), phosphorus (559), magnesium (547), and arsenic (536). The taxonomy of mineral species is discussed. The important advantage of the proposed systematics is the possibility to range mineral species in strict order, in which each of them would have a unique position. A simple way of ordering minerals opens up possibilities for computer indexing of thermodynamic information. Within each system, minerals are arranged in order of the number of atoms of the first element and, within the group of compounds with the same number of atoms of the first element, in order of the number of atoms of the second element, and so on.

Krivovichev, V. G.; Charykova, M. V.

2014-12-01

188

Getting the numbers right: statistical mischief and racial profiling in heart failure research.  

PubMed

The claim that blacks die from heart failure at a rate twice that of whites is informing efforts to develop and market the drug BiDil, which is currently undergoing clinical trials to be approved by the FDA as the first drug ever specified to treat African Americans--and only African Americans--for heart failure. The drug and its companion statistic have since come to play prominent roles in debates about so-called "racial profiling" in medicine and the legitimacy of using social categories of race in biomedical research. Nonetheless, this statistic is wrong. The most current data available place the black:white mortality ratio for heart failure at approximately 1.1:1. The article tells the story of attempts to get to the source of the supposed 2:1 mortality ratio and explores some of the implications of the acceptance of these erroneous data, both for the allocation of resources to combat disease and for our broader understanding of the nature and meaning of race. PMID:14593217

Kahn, Jonathan

2003-01-01

189

Quantum number conservation in the statistical bootstrap of fireball decay spectra  

Microsoft Academic Search

Quantum number conservation is considered within the stastistical ; bootstrap model by generalizing the bootstrap equation for the generating ; functional of fireball decay spectra. Explicit solutions are given for the level ; density and the generating functional in the case of additive quantum nunnbers as ; well as isospin conservation. Asymptotic expressions for the level density, the ; inclusive

E. M. Ilgenfritz; J. Kripfganz

1973-01-01

190

SCHOOL OF MATHEMATICS AND STATISTICS Autumn 2007-2008 Topics in Number Theory 2 hours  

E-print Network

) (ii) State Fermat's Last Theorem. Is it possible to have a Pythagorean triple in which all the numbers details to make it clear how you arrived at the answer. 1 (i) State Fermat's Little Theorem. (1 mark) (a (n, e) = (323, 7) and receive 11. Decode it. (13 marks) (ii) State Wilson's Theorem. (1 mark

191

A Statistical Analysis for Estimating Fish Number Density with the Use of a Multibeam Echosounder  

NASA Astrophysics Data System (ADS)

Fish number density can be estimated from the normalized second moment of acoustic backscatter intensity [Denbigh et al., J. Acoust. Soc. Am. 90, 457-469 (1991)]. This method assumes that the distribution of fish scattering amplitudes is known and that the fish are randomly distributed following a Poisson volume distribution within regions of constant density. It is most useful at low fish densities, relative to the resolution of the acoustic device being used, since the estimators quickly become noisy as the number of fish per resolution cell increases. New models that include noise contributions are considered. The methods were applied to an acoustic assessment of juvenile Atlantic Bluefin Tuna, Thunnus thynnus. The data were collected using a 400 kHz multibeam echo sounder during the summer months of 2009 in Cape Cod, MA. Due to the high resolution of the multibeam system used, the large size (approx. 1.5 m) of the tuna, and the spacing of the fish in the school, we expect there to be low fish densities relative to the resolution of the multibeam system. Results of the fish number density based on the normalized second moment of acoustic intensity are compared to fish packing density estimated using aerial imagery that was collected simultaneously.

Schroth-Miller, Madeline L.

192

Absolute copy number from the statistics of the quantification cycle in replicate quantitative polymerase chain reaction experiments.  

PubMed

The quantification cycle (Cq) is widely used for calibration in real-time quantitative polymerase chain reaction (qPCR), to estimate the initial amount, or copy number (N0), of the target DNA. Cq may be defined several ways, including the cycle where the detected fluorescence achieves a prescribed threshold level. For all methods of defining Cq, the standard deviation from replicate experiments is typically much greater than the estimated standard errors from the least-squares fits used to obtain Cq. For moderate-to-large copy number (N0 > 10(2)), pipet volume uncertainty and variability in the amplification efficiency (E) likely account for most of the excess variance in Cq. For small N0, the dispersion of Cq is determined by the Poisson statistics of N0, which means that N0 can be estimated directly from the variance of Cq. The estimation precision is determined by the statistical properties of ?(2), giving a relative standard deviation of ?(2/n)(1/2), where n is the number of replicates, for example, a 20% standard deviation in N0 from 50 replicates. PMID:25582662

Tellinghuisen, Joel; Spiess, Andrej-Nikolai

2015-02-01

193

Statistical and functional representations of the pattern of auroral energy flux, number flux, and conductivity  

SciTech Connect

Global patterns of the integral energy flux and average energy of precipitating auroral electrons are used to determine the global pattern of the electron-produced, height-integrated Hall and Pedersen conductivities. The conductivities were determined in spatial bins in magnetic local time (MLT)-corrected geomagnetic latitude (CGL) coordinates for all MLTs and for CGLs greater than 50 deg and for seven levels of activity as measured by Kp. On the nightside the two conductivities increase with increasing Kp. The largest conductivities are found near midnight, where the peak value of the Pedersen (Hall) conductivity varies from 3.09 (4.05) mhos to 12.5 (25.9) mhos as Kp varies from 0 > or = 6-. At noon and on much of morning side of the oval the Pedersen and Hall conductivities increase for Kp up to 2 and then decrease for higher Kp. The highest ratios of the Hall to Pedersen conductivity are on the morning side of the oval and at noon. The peak conductivities on the dayside are significant compared to the conductivities produced by solar radiation at all seasons of the year. The global maps of the integral energy flux, integral number flux, and height-integrated Hall and Pedersen conductivities at each level of Kp were fit using both spherical harmonic and Epstein functions. The Epstein functions were found to reproduce better the original maps. At Kp = 2 the distribution of differences between the Epstein function fit and the original data is roughly symmetric about zero with a full width at half maximum of 16 (20)% for the Pedersen (Hall) conductivity and 32(40)% for the integral energy (number) flux. The distribution of difference broadens with increasing and decreasing activity.

Hardy, D.A.; Gussenhoven, M.S.; Raistrick, R.

1987-11-01

194

Statistical and functional representations of the pattern of auroral energy flux, number flux, and conductivity  

SciTech Connect

The Hardy et al. (1985) global patterns of the the integral energy flux and average energy of precipitating auroral electrons are used to determine the global pattern of electron-produced, height-integrated Hall and Pedersen conductivities. THe conductivities were determined in spatial bins in magnetic local time (MLT)-corrected geomagnetic latitude (CGL) coordinates for all MLTs and for CGLs greater than 50/sup 0/ and for sevel levels of activity as measured by Kp. The conductivities vary smoothly with latitude and MLT typically having a single peak in latitude within the auroral oval at any MLT. On the nightside the two conductivities increase with increasing Kp. The largest conductivities are found near midnight, where the peak value of the Pederson (Hall) conductivity varies from 3.09 (4.05) mhos to 12.5 (25.9) mhos as Kp varies from 0 to greater than or equal to6-. The peak conductivity decreases with MLT away from midnight with the lowest peak values found postnoon. At noon and on much of the morning side of the oval the Pedersen and Hall conductivities increase for Kp up to 2 and then decrease for higher Kp. The highest ratios of the Hall to Petersen conductivity are on the morning side of the oval and at noon. The peak conductivities on the dayside are significant compared to the conductivities produced by solar radiation at all seasons of the year. The global maps of the integral energy flux, integral number flux, and height-integrated Hall and Pedersen conductivities at each level of Kp were fit using both spherical harmonic and Epstein functions. The Epstein functions were found to reproduce better the original maps.

Hardy, D.A.; Gussenhoven, M.S.; Raistrick, R.; McNeil, W.J.

1987-11-01

195

Super-Poissonian statistics of photon emission from single CdSe-CdS core-shell nanocrystals coupled to metal nanostructures.  

PubMed

We demonstrate that photon antibunching observed for individual nanocrystal quantum dots (NQDs) can be transformed into photon bunching characterized by super-Poissonian statistics when they are coupled to metal nanostructures (MNs). This observation indicates that, while the quantum yield of a biexciton (Q(2X)) is lower than that of a single exciton (Q(1X)) in freestanding NQDs, Q(2X) becomes greater than Q(1X) in NQDs coupled to MNs. This unique phenomenon is attributed to metal-induced quenching with a rate that scales more slowly with exciton multiplicity than the radiative decay rate and dominates over other nonradiative decay channels for both single excitons and biexcitons. PMID:25166575

Park, Young-Shin; Ghosh, Yagnaseni; Chen, Yongfen; Piryatinski, Andrei; Xu, Ping; Mack, Nathan H; Wang, Hsing-Lin; Klimov, Victor I; Hollingsworth, Jennifer A; Htoon, Han

2013-03-15

196

Dependence of spectral shape of bremsstrahlung spectra on atomic number of target materials in the photon energy range of 5-30 keV  

NASA Astrophysics Data System (ADS)

Dependence of spectral shape of total bremsstrahlung spectra i.e. the sum of ordinary bremsstrahlung (OB) and polarization bremsstrahlung (PB), on the atomic number ( Z) of target materials (Al, Ti, Sn and Pb), produced by continuous beta particles of 90Sr and 204Tl, has been investigated in the photon energy region of 5-30 keV. It has been found that the spectral shape of total bremsstrahlung spectra, in terms of S ( k, Z) i.e. the number of photons of energy k per moc2 per beta disintegration, is not linearly dependent on the atomic number ( Z) of the target material and rather it is proportional to Zn. At lower photon energies, the index values ' n' of Z-dependence are much higher than unity, which is due to the larger contribution of PB into OB. The decrease in ' n' values with increase of photon energy is due to the decrease in contribution of PB into OB. It is clear that the index ' n' values obtained from the modified Elwert factor (relativistic) Bethe-Heitler theory, which include the contribution PB into OB, are in agreement with the experimentally measured results using X-PIPS Si(Li) detector. Hence the contribution of PB into the formation of a spectral shape of total bremsstrahlung spectra plays a vital role.

Singh, Tajinder; Kahlon, K. S.; Dhaliwal, A. S.

2012-02-01

197

Usage Statistics  

MedlinePLUS

... Topics Drugs & Supplements Videos & Cool Tools ESPAÑOL MedlinePlus Statistics To use the sharing features on this page, please enable JavaScript. Quarterly User Statistics Graph | Quarterly User Statistics Table | Number of Health ...

198

Studies on effective atomic numbers for photon energy absorption and electron density of some narcotic drugs in the energy range 1 keV-20 MeV  

NASA Astrophysics Data System (ADS)

Effective atomic numbers for photon energy absorption ZPEA,eff, photon interaction ZPI,eff and for electron density Nel, have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for narcotic drugs, such as Heroin (H), Cocaine (CO), Caffeine (CA), Tetrahydrocannabinol (THC), Cannabinol (CBD), Tetrahydrocannabivarin (THCV). The ZPEA,eff, ZPI,eff and Nel values have been found to change with energy and composition of the narcotic drugs. The energy dependence ZPEA,eff, ZPI,eff and Nel is shown graphically. The maximum difference between the values of ZPEA,eff, and ZPI,eff occurs at 30 keV and the significant difference of 2 to 33% for the energy region 5-100 keV for all drugs. The reason for these differences is discussed.

Gounhalli, Shivraj G.; Shantappa, Anil; Hanagodimath, S. M.

2013-04-01

199

Statistical and hydrodynamic properties of double-ring polymers with a fixed linking number between twin rings  

NASA Astrophysics Data System (ADS)

For a double-ring polymer in solution we evaluate the mean-square radius of gyration and the diffusion coefficient through simulation of off-lattice self-avoiding double polygons consisting of cylindrical segments with radius rex of unit length. Here, a self-avoiding double polygon consists of twin self-avoiding polygons which are connected by a cylindrical segment. We show numerically that several statistical and dynamical properties of double-ring polymers in solution depend on the linking number of the constituent twin ring polymers. The ratio of the mean-square radius of gyration of self-avoiding double polygons with zero linking number to that of no topological constraint is larger than 1, in particular, when the radius of cylindrical segments rex is small. However, the ratio is almost constant with respect to the number of vertices, N, and does not depend on N. The large-N behavior of topological swelling is thus quite different from the case of knotted random polygons.

Uehara, Erica; Deguchi, Tetsuo

2014-01-01

200

Controllable single photon stimulation of retinal rod cells  

E-print Network

Retinal rod cells are commonly assumed to be sensitive to single photons [1, 2, 3]. Light sources used in prior experiments exhibit unavoidable fluctuations in the number of emitted photons [4]. This leaves doubt about the exact number of photons used to stimulate the rod cell. In this letter, we interface rod cells of Xenopus laevis with a light source based on Spontaneous Parametric Down Conversion (SPDC) [5], which provides one photon at a time. Precise control of generation of single photons and directional delivery enables us to provide unambiguous proof of single photon sensitivity of rod cells without relying on the statistical assumptions. Quantum correlations between single photons in the SPDC enable us to determine quantum efficiency of the rod cell without pre-calibrated reference detectors [6, 7, 8]. These results provide the path for exploiting resources offered by quantum optics in generation and manipulation of light in visual studies. From a more general perspective, this method offers the ult...

Phan, Nam Mai; Bessarab, Dmitri A; Krivitsky, Leonid A

2013-01-01

201

JTu5A.43.pdf Advanced Photonics Congress 2012 OSA Extreme value statistics in quasi-CW Raman fiber lasers  

E-print Network

do exist. It is found that the intensity PDF of the modes generated on the flat top at the spectrum fiber lasers Dmitry V. Churkin1,2 , Oleg A. Gorbunov2 , Sergey V. Smirnov3 1 Photonics Research Group in a Raman fiber laser. The mechanism of the extreme events generation is a turbulent-like four-wave mixing

Kobtsev, Sergei M.

202

CNTb, a set of scripts for batch processing and statistical analysis of photon correlation spectroscopy data via CONTIN inversion  

E-print Network

spectroscopy data via CONTIN inversion I. Echavarri Franco, J. Combet, and F. Schosseler Institut Charles allowing a batch inversion of series of photon correlation spectroscopy data files via CONTIN with a single is needed to test the reproducibility and the reliability of CONTIN output in difficult experimental

Boyer, Edmond

203

Statistical performance evaluation and comparison of a Compton medical imaging system and a collimated Anger camera for higher energy photon imaging  

NASA Astrophysics Data System (ADS)

In radionuclide treatment, tumor cells are primarily destroyed by charged particles emitted by the compound while associated higher energy photons are used to image the tumor in order to determine radiation dose and monitor shrinkage. However, the higher energy photons are difficult to image with conventional collimated Anger cameras, since a tradeoff exists between resolution and sensitivity, and the collimator septal penetration and scattering is increased due to the high energy photons. This research compares imaging performance of the conventional Anger camera to a Compton imaging system that can have improved spatial resolution and sensitivity for high energy photons because this tradeoff is decoupled, and the effect of Doppler broadening at higher gamma energies is decreased. System performance is analyzed by the modified uniform Cramer-Rao bound (M-UCRB) algorithms based on the developed system modeling. The bound shows that the effect of Doppler broadening is the limiting factor for Compton camera performance for imaging 364.4 keV photons emitted from 131I. According to the bound, the Compton camera outperforms the collimated system for an equal number of detected events when the desired spatial resolution for a 26 cm diameter uniform disk object is better than 12 mm FWHM. For a 3D cylindrical phantom, the lower bound on variance for the collimated camera is greater than for the Compton imaginer over the resolution range from 0.5 to 2 cm FWHM. Furthermore, the detection sensitivity of the proposed Compton imaging system is about 15-20 times higher than that of the collimated Anger camera.

Han, Li; Rogers, W. Leslie; Huh, Sam S.; Clinthorne, Neal

2008-12-01

204

Fixed-scale statistics and the geometry of turbulent dispersion at high Reynolds number via numerical simulation  

NASA Astrophysics Data System (ADS)

The relative dispersion of one uid particle with respect to another is fundamentally related to the transport and mixing of contaminant species in turbulent flows. The most basic consequence of Kolmogorov's 1941 similarity hypotheses for relative dispersion, the Richardson-Obukhov law that mean-square pair separation distance grows with the cube of time t3 at intermediate times in the inertial subrange, is notoriously difficult to observe in the environment, laboratory, and direct numerical simulations (DNS). Inertial subrange scaling in size parameters like requires careful adjustment for the initial conditions of the dispersion process as well as a very wide range of scales (high Reynolds number) in the flow being studied. However, the statistical evolution of the shapes of clusters of more than two particles has already exhibited statistical invariance at intermediate times in existing DNS. This invariance is identified with inertial-subrange scaling and is more readily observed than inertial-subrange scaling for the seemingly simpler quantity . Results from dispersion of clusters of four particles (called tetrads) in large-scale DNS at grid resolutions up to 40963 and Taylor-scale Reynolds numbers Rlambda from 140 to 1000 are used to explore the question of statistical universality in measures of the size and shape of tetrahedra in homogeneous isotropic turbulence in distinct scaling regimes at very small times (ballistic), intermediate times (inertial) and very late times (diffusive). Derivatives of 1/3 with respect to time normalized by the characteristic time scale at the initial tetrad size r0 constitute a powerful technique in isolating t3 scaling in . This technique is applied to the eigenvalues of a moment-of-inertia-like tensor formed from the separation vectors between particles in the tetrad. Estimates of the proportionality constant g in the Richardson-Obukhov t3 law from DNS at Rlambda ? 1000 converge towards the value g ? 0.56 reported in previous studies. The exit time taken by a particle pair to first reach successively larger thresholds of fixed separation distance is also brie y discussed and found to have unexplained dependence on initial separation distance for negative moments, but good inertial range scaling for positive moments. The use of diffusion models of relative dispersion in the inertial subrange to connect mean exit time to g is also tested and briefly discussed in these simulations. Mean values and probability density functions of shape parameters including the triangle aspect ratio w, tetrahedron volume-to-gyration radius ratio V2/3/R 2 and normalized moment-of-inertia eigenvalues are all found to approach invariant forms in the inertial subrange for a wider range of initial separations than size parameters such as mean-square gyration radius. These results constitute the clearest evidence to date that turbulence has a tendency to distort and elongate multiparticle configurations more severely in the inertial subrange than it does in the diffusive regime at asymptotically late time. Triangle statistics are found to be independent of initial shape for all time beyond the ballistic regime. The development and testing of different schemes for parallelizing the cubic spline interpolation procedure for particle velocities needed to track particles in DNS is also covered. A "pipeline" method of moving batches of particles from processor to processor is adopted due to its low memory overhead, but there are challenges in achieving good performance scaling.

Hackl, Jason F.

205

A new approach to mathematical statistics involving the number of degrees of freedom, temperature, and symplectically conjugate quantities  

NASA Astrophysics Data System (ADS)

We introduce several new notions in mathematical statistics that bridge the gap between this discipline and statistical physics. The analogy between them is useful both for mathematics and for physics. What is more, this new mathematical statistics is adequate for the study of computer networks and self-teaching systems. The role of the web in sociological and economic research is ascertained.

Maslov, V. P.; Maslova, T. V.

2013-07-01

206

Photon counting spectroscopy as done with a Thomson scattering diagnostic  

SciTech Connect

The measurement and reduction of photon counting spectral data is demonstrated within the context of a Thomson scattering diagnostic. This diagnostic contains a microchannel plate (MCP) photomultiplier tube (PMT) as the photon sensing device. The MCP PMT is not an ideal photon sensor, the loss of photoelectrons at the MCP input and the broad charge pulse distribution at the output add to the uncertainty in recorded data. Computer simulations are used to demonstrate an approach to quantification of this added uncertainty and to develop an understanding of its source; the methodology may be applicable to the development of an understanding of photon detectors other than an MCP PMT. Emphasis is placed on the Poisson statistical character of the data, because the assumption that a Gaussian probability distribution is a reasonable statistical description of photon counting data is often questionable. When the count rate is low, the product the possible number of photon counts and the probability of measurement of a single photon is usually not sufficiently large to justify Gaussian statistics. Rather, because probabilities of measurement are so low, the Poisson probability distribution best quantifies the inherent statistical fluctuations in such counting measurements. The method of maximum likelihood is applied to derive the Poisson statistics equivalent of {sub X}{sup 2}. A Poisson statistics based data fitting code is implemented using the Newton-Raphson method of multi-dimensional root finding; we also demonstrate an algorithm to estimate the uncertainties in derived quantities.

Den Hartog, D.J.; Ruppert, D.E.

1993-11-01

207

Exposure to Alcoholism in the Family: United States, 1988. Advance Data from Vital and Health Statistics of the National Center for Health Statistics. Number 205.  

ERIC Educational Resources Information Center

This report is based on data from the 1988 National Health Interview Survey on Alcohol (NHIS-Alcohol), part of the ongoing National Health Interview Survey conducted by the National Center for Health Statistics. Interviews for the NHIS are conducted in person by staff of the United States Bureau of the Census. Information is collected on each…

Schoenborn, Charlotte A.

208

Determination of Particle Size and Number Density of Opaque Colloidal Mixtures Using Diffuse Photon Density Waves and Two-Wavelength Light Sources  

NASA Astrophysics Data System (ADS)

A diffuse photon density wave (DPDW) propagates as a spherical energy wave in highly scattering media, such as opaque colloidal mixtures. The advantage of using DPDW is that the absorption and reduced scattering coefficients of the opaque colloidal mixtures can be measured without dilution and calibration. We propose a method for the estimation of the mean particle size and number density of the opaque colloidal mixtures using the relationship between estimated values and optical properties. In this study, we first determined the mean particle size and number density of colloidal silica, a single-particle dispersive medium, to confirm the validity of the method and evaluated the accuracy of the measurement. Then, we determined the mean particle size and number density of casein micelles and fat globules in milk, which is regarded as a typical opaque colloidal mixture, using two light sources with different wavelengths.

Taniguchi, Jun; Murata, Hiroshi; Okamura, Yasuyuki

2007-05-01

209

Single molecule studies of multiple-fluorophore labeled antibodies. Effect of homo-FRET on the number of photons available before photobleaching.  

PubMed

Advancements in single molecule detection (SMD) continue to unfold powerful ways to study the behavior of individual and complex molecular systems in real time. SMD enables the characterization of complex molecular interactions and reveals basic physical phenomena underlying chemical and biological processes. We present here a systematic study of the quenching efficiency of Förster-type energy-transfer (FRET) for multiple fluorophores immobilized on a single antibody. We simultaneously monitor the fluorescence intensity, fluorescence lifetime, and the number of available photons before photobleaching as a function of the number of identical emitters bound to a single IgG antibody. The detailed studies of FRET between individual fluorophores reveal complex through-space interactions. In general, even for two or three fluorophores immobilized on a single protein, homo-FRET interactions lead to an overall non-linear intensity increase and shortening of fluorescence lifetime. Over-labeling of protein in solution (ensemble) results in the loss of fluorescence signal due to the self-quenching of fluorophores making it useless for assays applications. However, in the single molecule regime, over-labeling may bring significant benefits in regards to the number of available photons and the overall survival time. Our investigation reveals possibilities to significantly increase the observation time for a single macromolecule allowing studies of macromolecular interactions that are not obscured by ensemble averaging. Extending the observation time will be crucial for developing immunoassays based on single-antibody. PMID:18855695

Luchowski, Rafal; Matveeva, Evgenia G; Gryczynski, Ignacy; Terpetschnig, Ewald A; Patsenker, Leonid; Laczko, Gabor; Borejdo, Julian; Gryczynski, Zygmunt

2008-10-01

210

Single Molecule Studies of Multiple-Fluorophore Labeled Antibodies. Effect of Homo-FRET on the Number of Photons Available Before Photobleaching  

PubMed Central

Advancements in single molecule detection (SMD) continue to unfold powerful ways to study the behavior of individual and complex molecular systems in real time. SMD enables the characterization of complex molecular interactions and reveals basic physical phenomena underlying chemical and biological processes. We present here a systematic study of the quenching efficiency of Förster-type energy-transfer (FRET) for multiple fluorophores immobilized on a single antibody. We simultaneously monitor the fluorescence intensity, fluorescence lifetime, and the number of available photons before photobleaching as a function of the number of identical emitters bound to a single IgG antibody. The detailed studies of FRET between individual fluorophores reveal complex through-space interactions. In general, even for two or three fluorophores immobilized on a single protein, homo-FRET interactions lead to an overall non-linear intensity increase and shortening of fluorescence lifetime. Over-labeling of protein in solution (ensemble) results in the loss of fluorescence signal due to the self-quenching of fluorophores making it useless for assays applications. However, in the single molecule regime, over-labeling may bring significant benefits in regards to the number of available photons and the overall survival time. Our investigation reveals possibilities to significantly increase the observation time for a single macromolecule allowing studies of macromolecular interactions that are not obscured by ensemble averaging. Extending the observation time will be crucial for developing immunoassays based on single-antibody. PMID:18855695

Luchowski, R.; Matveeva, E.G.; Gryczynski, I.; Terpetschnig, E.A.; Patsenker, L.; Laczko, G.; Borejdo, J.; Gryczynski, Z.

2009-01-01

211

True photo-counting statistics of multiple on-off detectors  

E-print Network

We derive a closed photo-counting formula, including noise counts and a finite quantum efficiency, for photon number resolving detectors based on on-off detectors. It applies to detection schemes such as array detectors and multiplexing setups. The result renders it possible to compare the corresponding measured counting statistics with the true photon number statistics of arbitrary quantum states. The photo-counting formula is applied to the discrimination of photon numbers of Fock states, squeezed states, and odd coherent states. It is illustrated for coherent states that our formula is indispensable for the correct interpretation of quantum effects observed with such devices.

J. Sperling; W. Vogel; G. S. Agarwal

2012-02-23

212

Nonclassicality generated by repeatedly operating photon annihilation-then-creation and creation-then-annihilation on squeezed vacuum  

NASA Astrophysics Data System (ADS)

We theoretically examine nonclassical properties of the field states generated by repeatedly applying photon annihilation-then-creation operation (AC) and creation-then-annihilation operation (CA) to the squeezed vacuum (SV). We firstly derive their normalization factors and then compare their statistical properties, such as photon number distribution, mean photon number, Mandel Q parameter, and the Wigner function. It is found that the ACSV can present more clear nonclassicality than the CASV.

Xu, Xue-xiang; Yuan, Hong-chun; Zhou, Lin

2015-01-01

213

Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking.  

PubMed

A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of "bright" and "dark" states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a "bright" and a "dark" maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed. PMID:24929377

Volkán-Kacsó, Sándor

2014-06-14

214

Determination of confidence limits for experiments with low numbers of counts. [Poisson-distributed photon counts from astrophysical sources  

NASA Technical Reports Server (NTRS)

Two different methods, classical and Bayesian, for determining confidence intervals involving Poisson-distributed data are compared. Particular consideration is given to cases where the number of counts observed is small and is comparable to the mean number of background counts. Reasons for preferring the Bayesian over the classical method are given. Tables of confidence limits calculated by the Bayesian method are provided for quick reference.

Kraft, Ralph P.; Burrows, David N.; Nousek, John A.

1991-01-01

215

Skin Conditions of Youths 12-17, United States. Vital and Health Statistics; Series 11, Number 157.  

ERIC Educational Resources Information Center

This report of the National Center for Health Statistics presents national estimates of the prevalence of facial acne and other skin lesions among noninstitutionalized youths aged 12-17 years by age, race, sex, geographic region, population size of place of residence, family income, education of parent, overall health, indications of stress,…

Roberts, Jean; Ludford, Jacqueline

216

Water equivalence study of some phantoms based on effective photon energy, effective atomic numbers and electron densities for clinical MV X-ray and Co-60 ?-ray beams  

NASA Astrophysics Data System (ADS)

A previously proposed procedure has been applied to some water equivalent phantoms namely PMMA, Polystyrene, Solid Water (WT1), RW3 and ABS for the first time to compute effective photon energy (Eeff), effective atomic numbers (Zeff) and electron densities (neeff) for different MV X-ray beams and Co-60 gamma beam which are heterogeneous in energy. For the purpose of the present investigation, effective atomic cross-sections of the given materials have been determined first to obtain effective photon energies which were further used for calculation of Zeff and neeff. Similar procedure was adopted for Co-60 ?-rays to check the validity of the present method. Results were found to be quite satisfactory. When it comes to the water equivalence, the Eeff results showed that the RW3 and ABS phantoms are more effective for 6 MV beam whereas RW3 and Polystyrene are more effective for 15 MV and Co-60 beams, respectively. The ABS and WT1 phantoms have better water equivalences than the others according to the Zeff and neeff results, respectively.

Kurudirek, Murat

2013-02-01

217

Photonic quantum well composed of photonic crystal and quasicrystal  

NASA Astrophysics Data System (ADS)

A photonic quantum well structure composed of photonic crystal and Fibonacci quasicrystal is investigated by analyzing the transmission spectra and electric field distributions. The defect band in the photonic well can form confined quantized photonic states that can change in the band-gap of the photonic barriers by varying the thickness ratio of the two stacking layers. The number of confined states can be tuned by adjusting the period of the photonic well. The photons traverse the photonic quantum well by resonance tunneling and the coupling effect leads to the high transmission intensity of the confined photonic states.

Xu, Shaohui; Zhu, Yiping; Wang, Lianwei; Yang, Pingxiong; Chu, Paul K.

2014-02-01

218

Photon Amplification  

NASA Astrophysics Data System (ADS)

This thesis consists of three self-contained chapters pertaining to mechanisms of photon amplification. All have been published or submitted for publication. In Chapter 1, we show that the photon point process at the output of a traveling-wave amplifier (TWA) with coherent input light is characterized by a marked-Poisson (MP) process which consequently results in a noncentral negative binomial (NNB) output-photon-number distribution. For an on/off keying (OOK) direct-detection lightwave communication system incorporating a TWA, the probability of error (PE) calculated from the NNB distributions turns out to be superior, but unexpectedly close to that calculated from the Gaussian approximation. In Chapter 2, we show that the photon-number distribution (PND) at the output of a cascade of TWAs with identical normalized bandwidth and with coherent light at the input turns out to be the NNB distribution, even in the presence of intervening loss. The PE of a cascade of several high gain TWAs is essentially the same as that of a single one. In addition, the PE of a sequence of postamplifiers is superior to that of a sequence of preamplifiers. In Chapter 3, we construct a mathematical model for describing the mechanisms of photon amplification employed by a living system (the vertebrate rod). The thrust of this work is to glean an understanding of how a biological system makes use of photon amplification. The cyclic-GMP cascade represents the excitation of the retinal rod photoreceptor by a single photon. Our investigation shows that the relative noise of the rod photocurrent, which ensues from a filtering of the discrete multiplication process, is determined primarily by the first stage of the excitatory cascade. Our analysis also shows that the conversion of the discrete multiplied signal into a current reduces the output relative noise when it is measured in terms of the variance-to-mean ratio.

Li, Tao

1992-01-01

219

Statistical Studies on Protein Polymorphism in Natural Populations. III. Distribution of Allele Frequencies and the Number of Alleles per Locus  

PubMed Central

With the aim of understanding the mechanism of maintenance of protein polymorphism, we have studied the properties of allele frequency distribution and the number of alleles per locus, using gene-frequency data from a wide range of organisms (mammals, birds, reptiles, amphibians, Drosophila and non-Drosophila invertebrates) in which 20 or more loci with at least 100 genes were sampled. The observed distribution of allele frequencies was U-shaped in all of the 138 populations (mostly species or subspecies) examined and generally agreed with the theoretical distribution expected under the mutation-drift hypothesis, though there was a significant excess of rare alleles (gene frequency, 0 ? 0.05) in about a quarter of the populations. The agreement between the mutation-drift theory and observed data was quite satisfactory for the numbers of polymorphic (gene frequency, 0.05 ? 0.95) and monomorphic (0.95 ? 1.0) alleles.—The observed pattern of allele-frequency distribution was incompatible with the prediction from the overdominance hypothesis. The observed correlations of the numbers of rare alleles, polymorphic alleles and monomorphic alleles with heterozygosity were of the order of magnitude that was expected under the mutation-drift hypothesis. Our results did not support the view that intracistronic recombination is an important source of genetic variation. The total number of alleles per locus was positively correlated with molecular weight in most of the species examined, and the magnitude of the correlation was consistent with the theoretical prediction from mutation-drift hypothesis. The correlation between molecular weight and the number of alleles was generally higher than the correlation between molecular weight and heterozygosity, as expected. PMID:17249018

Chakraborty, Ranajit; Fuerst, Paul A.; Nei, Masatoshi

1980-01-01

220

Implication of nonintegral occupation number and Fermi-Dirac statistics in the local-spin-density approximation applied to finite systems  

SciTech Connect

In electronic-structure calculations for finite systems using the local-spin-density (LSD) approximation, it is assumed that the eigenvalues of the Kohn-Sham equation should obey Fermi-Dirac (FD) statistics. In order to comply with this assumption for some of the transition-metal atoms, a nonintegral occupation number is used which also minimizes the total energy. It is shown here that for finite systems it is not necessary that the eigenvalues of the Kohn-Sham equation obey FD statistics. It is also shown that the Kohn-Sham exchange potential used in all LSD models is correct only for integer occupation number. With a noninteger occupation number the LSD exchange potential will be smaller than that given by the Kohn-Sham potential. Ab initio self-consistent spin-polarized calculations have been performed numerically for the total energy of an iron atom. It is found that the ground state belongs to the 3d/sup 6/4s/sup 2/ configuration. The ionization potentials of all the Fe/sup n//sup +/ ions are reported and are in agreement with experiment.

Dhar, S.

1989-02-01

221

A bias free true random number generator  

E-print Network

We propose a new approach to nondeterministic random number generation. In theory, the randomness originated from the uncorrelated nature of consecutive laser pulses with Poissonian photon number distribution and that of the consecutive single photon detections is used to generate random bit. In experiment, von Neumann correction method is applied to extract the final random bit. This method is proved to be bias free in randomness generation, provided that the single photon detections are mutually independent, and further, it has the advantage in generation efficiency of random bits since no postprocessing is needed. A true random number generator based on this new method is realized and its randomness is guaranteed using three batteries of statistical tests.

Wei Wei; Hong Guo

2009-05-15

222

Statistics of multiphoton events in spontaneous parametric down-conversion  

E-print Network

We present an experimental characterization of the statistics of multiple photon pairs produced by spontaneous parametric down-conversion realized in a nonlinear medium pumped by high-energy ultrashort pulses from a regenerative amplifier. The photon number resolved measurement has been implemented with the help of a fiber loop detector. We introduce an effective theoretical description of the observed statistics based on parameters that can be assigned direct physical nterpretation. These parameters, determined for our source from the collected experimental data, characterize the usefulness of down-conversion sources in multiphoton interference schemes that underlie protocols for quantum information processing and communication.

Wojciech Wasilewski; Czeslaw Radzewicz; Robert Frankowski; Konrad Banaszek

2008-05-12

223

Tailored quantum statistics from broadband states of light  

E-print Network

We analyze the statistics of photons originating from amplified spontaneous emission generated by a quantum dot superluminescent diode. Experimentally detectable emission properties are taken into account by parametrizing the corresponding quantum state as a multi-mode phase-randomized Gaussian density operator. The validity of this model is proven in two subsequent experiments using fast two-photon-absorption detection observing second order equal-time- as well as second order fully time-resolved intensity correlations on femtosecond timescales. In the first experiment, we study the photon statistics when the number of contributing longitudinal modes is systematically reduced by applying well-controlled optical feedback. In a second experiment, we add coherent light from a single-mode laserdiode to quantum dot superluminescent diode broadband radiation. Tuning the power ratio, we realize tailored second order correlations ranging from Gaussian to Poissonian statistics. Both experiments are very well matched ...

Hartmann, S; Molitor, A; Reichert, M; Elsäßer, W; Walser, R

2014-01-01

224

Quantum nonlinear optics -- photon by photon  

NASA Astrophysics Data System (ADS)

The realization of strong interactions between individual photons is a long-standing goal of both fundamental and technological significance. Scientists have known for over half a century that light fields can interact inside nonlinear optical media, but the nonlinearity of conventional materials is negligible at the light powers associated with individual photons. Nevertheless, remarkable advances in quantum optics have recently culminated in the demonstration of several methods for generating optical nonlinearities at the level of individual photons. Systems exhibiting strong photon-photon interactions enable a number of unique applications, including quantum-by-quantum control of light fields, single-photon switches and transistors, all-optical deterministic quantum logic, and the realization of strongly correlated states of light and matter.

Chang, Darrick E.; Vuleti?, Vladan; Lukin, Mikhail D.

2014-09-01

225

Photon-photon colliders  

SciTech Connect

Since the seminal work by Ginsburg, et at., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention. A 1990 article by V.I. Teinov describes the situation at that time. In March 1994, the first workshop on this subject was held. This report briefly reviews the physics that can be achieved through the photon-photon channel and then focuses on the means of achieving such a collider. Also reviewed is the spectrum of backscattered Compton photons -- the best way of obtaining photons. We emphasize the spectrum actually obtained in a collider with both polarized electrons and photons (peaked at high energy and very different from a Compton spectrum). Luminosity is estimated for the presently considered colliders, and interaction and conversion-point geometries are described. Also specified are laser requirements (such as wavelength, peak power, and average power) and the lasers that might be employed. These include conventional and free-electron lasers. Finally, we describe the R&D necessary to make either of these approaches viable and explore the use of the SLC as a test bed for a photon-photon collider of very high energy.

Sessler, A.M.

1995-04-01

226

Hybrid laser with CMOS photonics  

E-print Network

In this thesis, an interesting approach for a photonic laser source is presented. By using integrated photonic resonators with an external gain medium, we are able to build a laser that offers a number of advantages including ...

Chong, Johanna S

2014-01-01

227

Quantification of Tc-99m-ethyl cysteinate dimer brain single photon emission computed tomography images using statistical probabilistic brain atlas in depressive end-stage renal disease patients  

PubMed Central

This study adapted a statistical probabilistic anatomical map of the brain for single photon emission computed tomography images of depressive end-stage renal disease patients. This research aimed to investigate the relationship between symptom clusters, disease severity, and cerebral blood flow. Twenty-seven patients (16 males, 11 females) with stages 4 and 5 end-stage renal disease were enrolled, along with 25 healthy controls. All patients underwent depressive mood assessment and brain single photon emission computed tomography. The statistical probabilistic anatomical map images were used to calculate the brain single photon emission computed tomography counts. Asymmetric index was acquired and Pearson correlation analysis was performed to analyze the correlation between symptom factors, severity, and regional cerebral blood flow. The depression factors of the Hamilton Depression Rating Scale showed a negative correlation with cerebral blood flow in the left amygdale. The insomnia factor showed negative correlations with cerebral blood flow in the left amygdala, right superior frontal gyrus, right middle frontal gyrus, and left middle frontal gyrus. The anxiety factor showed a positive correlation with cerebral glucose metabolism in the cerebellar vermis and a negative correlation with cerebral glucose metabolism in the left globus pallidus, right inferior frontal gyrus, both temporal poles, and left parahippocampus. The overall depression severity (total scores of Hamilton Depression Rating Scale) was negatively correlated with the statistical probabilistic anatomical map results in the left amygdala and right inferior frontal gyrus. In conclusion, our results demonstrated that the disease severity and extent of cerebral blood flow quantified by a probabilistic brain atlas was related to various brain areas in terms of the overall severity and symptom factors in end-stage renal disease patients.

Kim, Heeyoung; Kim, In Joo; Kim, Seong-Jang; Song, Sang Heon; Pak, Kyoungjune; Kim, Keunyoung

2012-01-01

228

STATISTICAL METHODS STATISTICAL METHODS  

E-print Network

STATISTICAL METHODS 1 STATISTICAL METHODS Arnaud Delorme, Swartz Center for Computational@salk.edu. Keywords: statistical methods, inference, models, clinical, software, bootstrap, resampling, PCA, ICA Abstract: Statistics represents that body of methods by which characteristics of a population are inferred

Delorme, Arnaud

229

RANDOMNESS of Numbers DEFINITION(QUERY:WHAT? V HOW?) ONLY Via MAXWELL-BOLTZMANN CLASSICAL-Statistics(MBCS) Hot-Plasma VS. Digits-Clumping Log-Law NON-Randomness Inversion ONLY BOSE-EINSTEIN QUANTUM-Statistics(BEQS) .  

NASA Astrophysics Data System (ADS)

RANDOMNESS of Numbers cognitive-semantics DEFINITION VIA Cognition QUERY: WHAT???, NOT HOW?) VS. computer-"science" mindLESS number-crunching (Harrel-Sipser-...) algorithmics Goldreich "PSEUDO-randomness"[Not.AMS(02)] mea-culpa is ONLY via MAXWELL-BOLTZMANN CLASSICAL-STATISTICS(NOT FDQS!!!) "hot-plasma" REPULSION VERSUS Newcomb(1881)-Weyl(1914;1916)-Benford(1938) "NeWBe" logarithmic-law digit-CLUMPING/ CLUSTERING NON-Randomness simple Siegel[AMS Joint.Mtg.(02)-Abs. # 973-60-124] algebraic-inversion to THE QUANTUM and ONLY BEQS preferentially SEQUENTIALLY lower-DIGITS CLUMPING/CLUSTERING with d = 0 BEC, is ONLY VIA Siegel-Baez FUZZYICS=CATEGORYICS (SON OF TRIZ)/"Category-Semantics"(C-S), latter intersection/union of Lawvere(1964)-Siegel(1964)] category-theory (matrix: MORPHISMS V FUNCTORS) "+" cognitive-semantics" (matrix: ANTONYMS V SYNONYMS) yields Siegel-Baez FUZZYICS=CATEGORYICS/C-S tabular list-format matrix truth-table analytics: MBCS RANDOMNESS TRUTH/EMET!!!

Siegel, Z.; Carl-Ludwig Siegel, Edward

2011-03-01

230

Photon-assisted Landau-Zener transition: Role of coherent superposition states  

NASA Astrophysics Data System (ADS)

We investigate a Landau-Zener (LZ) transition process modeled by a quantum two-level system (TLS) coupled to a photon mode when the bias energy is varied linearly in time. The initial state of the photon field is assumed to be a superposition of coherent states, leading to a more intricate LZ transition. Applying the rotating-wave approximation (RWA), analytical results are obtained revealing the enhancement of the LZ probability by increasing the average photon number. We also consider the creation of entanglement and the change of photon statistics during the LZ process. Without the RWA, we find some qualitative differences of the LZ dynamics from the RWA results; e.g., the average photon number no longer monotonically enhances the LZ probability. The ramifications and implications of these results are explored.

Sun, Zhe; Ma, Jian; Wang, Xiaoguang; Nori, Franco

2012-07-01

231

a Study of the Quantum Nature of Light: Macroscopic Quantum Jumps from a Two-Atom System, Photon Statistics, and Light Propagation  

NASA Astrophysics Data System (ADS)

In my dissertation, first, I show that when a pair of two-level atoms are confined in a region whose linear dimension is much smaller than the resonant wavelength, the intensity fluorescence exhibits dark and bright periods. The time scale for these "macroscopic quantum jumps" is the order of the lifetime of the metastable state. The creation of this metastable state is a direct consequence of the cooperative interaction between the atoms. My analysis is based on the study of quasi-steady-state populations and frequency resolved delay functions, an extension of a concept introduced by S. Reynaud, J. Dalibard, and C. Cohen-Tannoudji (IEEE J. Quant. Elec. 24, 1395 (1988)). I also show that these concepts simplify both calculations and interpretations in many problems involving macroscopic quantum jumps. Second, I study the quantum statistical properties of the fluorescence from one two-level and two two-level atoms. The generation of sub-Poissonian light, in which the intensity fluctuations are smaller than the classical limit, is investigated. I show that the two systems considered are capable of generating sub-Poissonian light under certain conditions. My analysis is based on the frequency resolved delay functions and branching functions developed in Chapter I. My method is found to be simpler than the conventional approach which is based on second order correlation functions of the field. Third, I study pulse propagation through a nonlinear medium. The field representing the pulse is quantized and the medium is made up of randomly distributed identical two-level atoms. I show that operator versions of the Maxwell-Bloch equations with added Langevin fluctuating terms and a c-number source term correctly describe the propagation of the pulse. I solve these equations in the weak field regime and show that many results predicted by a semiclassical theory of this problem are reproduced, and that no quantum property of the field plays an important role in this regime. I also solve the same equations in the strong field regime and show that quantum noise, which is the direct manifestation of the quantized nature of the field, is created and subsequently amplified as the pulse propagates through the medium.

Yamada, Keiichi

1990-08-01

232

Photon-photon collisions  

SciTech Connect

The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

Brodsky, S.J.

1985-01-01

233

Nonclassical properties and decoherence of fields in photon-added squeezing-enhanced thermal states  

NASA Astrophysics Data System (ADS)

We put forward the photon-added squeezing-enhanced thermal states (PASETS) theoretically by adding photon to the squeezed enhancing thermal states (SETS) repeatedly. Based on the normally ordered density operator of PASETS, we investigate the nonclassical behavior of the PASETS by evaluating, both analytically and numerically, Mandel's Q-parameter, photon-number distribution (PND), and Wigner function (WF). It is found that smaller squeezing parameter r and thermal photon number nc can lead to more chance of the appearance of sub-Poissonian statistics. And it is shown that the PND of PASETS exhibit more remarkable oscillations than that of SETS in stronger squeezing case. The WF exhibit partial negativity in phase space and the squeezing parameter r can result in both squeezing and rotating effect. By investigating the fidelity between PASETS and SETS shows that the fidelity tender to steady values in the high value of squeezing parameter or thermal photon number. In addition, the decoherence effect on the PASETS is examined by the time-evolution of the analytical WF in thermal channel. The results show that the PASETS shall lose nonclassicality and non-Gaussianity and reduce to classical states with Gaussian distribution after sufficient time interaction with the thermal noise. And larger photon-added number or thermal photon number shall render shorter decoherence time.

Wang, Zhen; Meng, Xiang-Guo; Li, Heng-Mei; Yuan, Hong-Chun

2014-04-01

234

Statistics Indonesia  

NSDL National Science Digital Library

Started in 1997, the Badan Pusat Statistik (BPS-Statistics Indonesia) is a non-departmental Indonesian government institution directly responsible to the Indonesian president. As the law that created this valuable institution stipulates, the BPS is intended to provide data to the government and the public, along cooperating with other international statistical institutions. Visitors looking for statistics on any number of topics will not be disappointed, as the areas covered include agriculture, consumer price indices, employment, energy, foreign trade, mining, population, public finance, tourism, and social welfare. Additionally, there are monthly macro-economic statistical reports for the years from 1998 to 2001 that can be downloaded and viewed as well. The site is rounded out by a collection of some 21 papers from the past four years that analyze various economic data from the country, such as earning data and manufacturing production.

235

Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation  

SciTech Connect

The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the N-photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.

Ide, Toshiki; Hofmann, Holger F. [Okayama Institute for Quantum Physics, 1-9-1 Kyoyama, Okayama City, Okayama, 700-0015 (Japan); JST-CREST, Graduate School of Advanced Sciences of Matter, Hiroshima University, Kagamiyama 1-3-1, Higashi Hiroshima 739-8530 (Japan)

2007-06-15

236

The thermalization, condensation and flickering of photons  

NASA Astrophysics Data System (ADS)

Other than in a three-dimensional thermal photon gas as Planck?s blackbody radiation, photons can exhibit Bose–Einstein condensation, if the thermalization process is restricted to two motional degrees of freedom. This self-contained tutorial describes the thermalization mechanism, the condensation process and the quantum statistics of the photon condensates in detail.

Klaers, Jan

2014-12-01

237

Direct Photons at RHIC  

SciTech Connect

Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum (p{sub T}) range. The p+p measurements allow a fundamental test of QCD, and serve as a baseline when we try to disentangle more complex mechanisms producing high p{sub T} direct photons in Au+Au. As for thermal photons in Au+Au we overcome the difficulties due to the large background from hadronic decays by measuring 'almost real' virtual photons which appear as low invariant mass e{sup +}e{sup -} pairs: a significant excess of direct photons is measured above the above next-to-leading order perturbative quantum chromodynamics calculations. Additional insights on the origin of direct photons can be gained with the study of the azimuthal anisotropy which benefits from the increased statistics and reaction plane resolution achieved in RHIC Year-7 data.

Gabor,D.

2008-07-29

238

Experimental validation of photonic boson sampling  

NASA Astrophysics Data System (ADS)

A boson sampling device is a specialized quantum computer that solves a problem that is strongly believed to be computationally hard for classical computers. Recently, a number of small-scale implementations have been reported, all based on multiphoton interference in multimode interferometers. Akin to several quantum simulation and computation tasks, an open problem in the hard-to-simulate regime is to what extent the correctness of the boson sampling outcomes can be certified. Here, we report new boson sampling experiments on larger photonic chips and analyse the data using a recently proposed scalable statistical test. We show that the test successfully validates small experimental data samples against the hypothesis that they are uniformly distributed. In addition, we show how to discriminate data arising from either indistinguishable or distinguishable photons. Our results pave the way towards larger boson sampling experiments whose functioning, despite being non-trivial to simulate, can be certified against alternative hypotheses.

Spagnolo, Nicolò; Vitelli, Chiara; Bentivegna, Marco; Brod, Daniel J.; Crespi, Andrea; Flamini, Fulvio; Giacomini, Sandro; Milani, Giorgio; Ramponi, Roberta; Mataloni, Paolo; Osellame, Roberto; Galvão, Ernesto F.; Sciarrino, Fabio

2014-08-01

239

Photoelectron anticorrelations and sub-Poisson statistics in scintillation detectors  

PubMed Central

The performance of scintillation detectors for x rays and gamma rays is limited fundamentally by the statistics of the scintillation light and the resulting photoelectrons. This paper presents a new experimental approach to studying these statistics by observing correlations in the signals from two photodetectors. It is shown that the Fano factors (ratios of variance to mean), both for the number the photoelectrons produced on the photocathode of the photomultiplier and for the underlying number of scintillation photons, can be deduced from these correlations. For LaBr3(Ce) and 662 keV gamma rays, the photopeak signals obtained by photomultipliers on opposite faces of a thin sample are negatively correlated, and the Fano factor for the photoelectrons is significantly less than one. The inferred Fano factor for the optical photons is very small, indistinguishable from zero within experimental error. PMID:20725609

Bousselham, Abdelkader; Barrett, Harrison H.; Bora, Vaibhav; Shah, Kanai

2010-01-01

240

Breakthroughs in Photonics 2009  

E-print Network

Breakthroughs in Photonics 2009 Breakthroughs in Photonics 2009 Coherent Photon Sources Ultrafast Photonics Journal Breakthroughs in Photonics 2009 Breakthroughs in Photonics 2009 Table of Contents Editorial Breakthroughs in Photonics 2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. Menoni

Keller, Ursula

241

Detector noise statistics in the non-linear regime  

NASA Technical Reports Server (NTRS)

The statistical behavior of an idealized linear detector in the presence of threshold and saturation levels is examined. It is assumed that the noise is governed by the statistical fluctuations in the number of photons emitted by the source during an exposure. Since physical detectors cannot have infinite dynamic range, our model illustrates that all devices have non-linear regimes, particularly at high count rates. The primary effect is a decrease in the statistical variance about the mean signal due to a portion of the expected noise distribution being removed via clipping. Higher order statistical moments are also examined, in particular, skewness and kurtosis. In principle, the expected distortion in the detector noise characteristics can be calibrated using flatfield observations with count rates matched to the observations. For this purpose, some basic statistical methods that utilize Fourier analysis techniques are described.

Shopbell, P. L.; Bland-Hawthorn, J.

1992-01-01

242

Lifetime statistics of quantum chaos studied by a multiscale analysis  

SciTech Connect

In a series of pump and probe experiments, we study the lifetime statistics of a quantum chaotic resonator when the number of open channels is greater than one. Our design embeds a stadium billiard into a two dimensional photonic crystal realized on a silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory with an excellent level of agreement.

Di Falco, A.; Krauss, T. F. [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, KY16 9SS (United Kingdom); Fratalocchi, A. [PRIMALIGHT, Faculty of Electrical Engineering, Applied Mathematics and Computational Science, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)

2012-04-30

243

Random Number Generation Using Amplified Spontaneous Emission in a Fiber Amplifier  

E-print Network

Random Number Generation Using Amplified Spontaneous Emission in a Fiber Amplifier Julia C. Salevan methods including photon counting and chaotic systems. · We examine an optical system using the amplified spontaneous emission in a fiber amplifier as our random source. System Conclusions and Future Work Statistical

Anlage, Steven

244

The photon gas formulation of thermal radiation  

NASA Technical Reports Server (NTRS)

A statistical consideration of the energy, the linear momentum, and the angular momentum of the photons that make up a thermal radiation field was presented. A general nonequilibrium statistical thermodynamics approach toward a macroscopic description of thermal radiation transport was developed and then applied to the restricted equilibrium statistical thermostatics derivation of the energy, linear momentum, and intrinsic angular momentum equations for an isotropic photon gas. A brief treatment of a nonisotropic photon gas, as an example of the results produced by the nonequilibrium statistical thermodynamics approach, was given. The relativistic variation of temperature and the invariance of entropy were illustrated.

Ried, R. C., Jr.

1975-01-01

245

Controllable stimulation of retinal rod cells using single photons  

E-print Network

New tools and approaches of quantum optics offer a unique opportunity to generate light pulses carrying a precise number of photons. Accurate control over the light pulses helps to improve the characterization of photo-induced processes. Here, we interface a specialized light source which provides flashes containing just one photon, with retinal rod cells of Xenopus laevis toads. We provide unambiguous proof of single photon sensitivity of rod cells without relying on the statistical modeling. We determined their quantum efficiencies without the use of any pre-calibrated detectors, and obtained the value of 29+-4.7 %. Our approach provides the path for future studies and applications of quantum properties of light in phototransduction, vision, and photosynthesis.

Nam Mai Phan; Mei Fun Cheng; Dmitri A. Bessarab; Leonid A. Krivitsky

2013-08-03

246

Quantum Storage of a Photonic Polarization Qubit in a Solid  

NASA Astrophysics Data System (ADS)

We report on the quantum storage and retrieval of photonic polarization quantum bits onto and out of a solid state storage device. The qubits are implemented with weak coherent states at the single photon level, and are stored for a predetermined time of 500 ns in a praseodymium doped crystal with a storage and retrieval efficiency of 10%, using the atomic frequency comb scheme. We characterize the storage by using quantum state tomography, and find that the average conditional fidelity of the retrieved qubits exceeds 95% for a mean photon number ?=0.4. This is significantly higher than a classical benchmark, taking into account the Poissonian statistics and finite memory efficiency, which proves that our crystal functions as a quantum storage device for polarization qubits. These results extend the storage capabilities of solid state quantum light matter interfaces to polarization encoding, which is widely used in quantum information science.

Gündo?an, Mustafa; Ledingham, Patrick M.; Almasi, Attaallah; Cristiani, Matteo; de Riedmatten, Hugues

2012-05-01

247

Prospects for in vivo estimation of photon linear attenuation coefficients using postprocessing dual-energy CT imaging on a commercial scanner: Comparison of analytic and polyenergetic statistical reconstruction algorithms  

PubMed Central

Purpose: Accurate patient-specific photon cross-section information is needed to support more accurate model-based dose calculation for low energy photon-emitting modalities in medicine such as brachytherapy and kilovoltage x-ray imaging procedures. A postprocessing dual-energy CT (pDECT) technique for noninvasive in vivo estimation of photon linear attenuation coefficients has been experimentally implemented on a commercial CT scanner and its accuracy assessed in idealized phantom geometries. Methods: Eight test materials of known composition and density were used to compare pDECT-estimated linear attenuation coefficients to NIST reference values over an energy range from 10 keV to 1 MeV. As statistical image reconstruction (SIR) has been shown to reconstruct images with less random and systematic error than conventional filtered backprojection (FBP), the pDECT technique was implemented with both an in-house polyenergetic SIR algorithm, alternating minimization (AM), as well as a conventional FBP reconstruction algorithm. Improvement from increased spectral separation was also investigated by filtering the high-energy beam with an additional 0.5 mm of tin. The law of propagated uncertainty was employed to assess the sensitivity of the pDECT process to errors in reconstructed images. Results: Mean pDECT-estimated linear attenuation coefficients for the eight test materials agreed within 1% of NIST reference values for energies from 1 MeV down to 30 keV, with mean errors rising to between 3% and 6% at 10 keV, indicating that the method is unbiased when measurement and calibration phantom geometries are matched. Reconstruction with FBP and AM algorithms conferred similar mean pDECT accuracy. However, single-voxel pDECT estimates reconstructed on a 1 × 1 × 3 mm3 grid are shown to be highly sensitive to reconstructed image uncertainty; in some cases pDECT attenuation coefficient estimates exhibited standard deviations on the order of 20% around the mean. Reconstruction with the statistical AM algorithm led to standard deviations roughly 40% to 60% less than FBP reconstruction. Additional tin filtration of the high energy beam exhibits similar pDECT estimation accuracy as the unfiltered beam, even when scanning with only 25% of the dose. Using the law of propagated uncertainty, low Z materials are found to be more sensitive to image reconstruction errors than high Z materials. Furthermore, it is estimated that reconstructed CT image uncertainty must be limited to less than 0.25% to achieve a target linear-attenuation coefficient estimation uncertainty of 3% at 28 keV. Conclusions: That pDECT supports mean linear attenuation coefficient measurement accuracies of 1% of reference values for energies greater than 30 keV is encouraging. However, the sensitivity of the pDECT measurements to noise and systematic errors in reconstructed CT images warrants further investigation in more complex phantom geometries. The investigated statistical reconstruction algorithm, AM, reduced random measurement uncertainty relative to FBP owing to improved noise performance. These early results also support efforts to increase DE spectral separation, which can further reduce the pDECT sensitivity to measurement uncertainty. PMID:24320525

Evans, Joshua D.; Whiting, Bruce R.; O’Sullivan, Joseph A.; Politte, David G.; Klahr, Paul H.; Yu, Yaduo; Williamson, Jeffrey F.

2013-01-01

248

Prospects for in vivo estimation of photon linear attenuation coefficients using postprocessing dual-energy CT imaging on a commercial scanner: Comparison of analytic and polyenergetic statistical reconstruction algorithms  

SciTech Connect

Purpose: Accurate patient-specific photon cross-section information is needed to support more accurate model-based dose calculation for low energy photon-emitting modalities in medicine such as brachytherapy and kilovoltage x-ray imaging procedures. A postprocessing dual-energy CT (pDECT) technique for noninvasivein vivo estimation of photon linear attenuation coefficients has been experimentally implemented on a commercial CT scanner and its accuracy assessed in idealized phantom geometries. Methods: Eight test materials of known composition and density were used to compare pDECT-estimated linear attenuation coefficients to NIST reference values over an energy range from 10 keV to 1 MeV. As statistical image reconstruction (SIR) has been shown to reconstruct images with less random and systematic error than conventional filtered backprojection (FBP), the pDECT technique was implemented with both an in-house polyenergetic SIR algorithm, alternating minimization (AM), as well as a conventional FBP reconstruction algorithm. Improvement from increased spectral separation was also investigated by filtering the high-energy beam with an additional 0.5 mm of tin. The law of propagated uncertainty was employed to assess the sensitivity of the pDECT process to errors in reconstructed images. Results: Mean pDECT-estimated linear attenuation coefficients for the eight test materials agreed within 1% of NIST reference values for energies from 1 MeV down to 30 keV, with mean errors rising to between 3% and 6% at 10 keV, indicating that the method is unbiased when measurement and calibration phantom geometries are matched. Reconstruction with FBP and AM algorithms conferred similar mean pDECT accuracy. However, single-voxel pDECT estimates reconstructed on a 1 × 1 × 3 mm{sup 3} grid are shown to be highly sensitive to reconstructed image uncertainty; in some cases pDECT attenuation coefficient estimates exhibited standard deviations on the order of 20% around the mean. Reconstruction with the statistical AM algorithm led to standard deviations roughly 40% to 60% less than FBP reconstruction. Additional tin filtration of the high energy beam exhibits similar pDECT estimation accuracy as the unfiltered beam, even when scanning with only 25% of the dose. Using the law of propagated uncertainty, low Z materials are found to be more sensitive to image reconstruction errors than high Z materials. Furthermore, it is estimated that reconstructed CT image uncertainty must be limited to less than 0.25% to achieve a target linear-attenuation coefficient estimation uncertainty of 3% at 28 keV. Conclusions: That pDECT supports mean linear attenuation coefficient measurement accuracies of 1% of reference values for energies greater than 30 keV is encouraging. However, the sensitivity of the pDECT measurements to noise and systematic errors in reconstructed CT images warrants further investigation in more complex phantom geometries. The investigated statistical reconstruction algorithm, AM, reduced random measurement uncertainty relative to FBP owing to improved noise performance. These early results also support efforts to increase DE spectral separation, which can further reduce the pDECT sensitivity to measurement uncertainty.

Evans, Joshua D., E-mail: jevans2@mcvh-vcu.edu; Yu, Yaduo; Williamson, Jeffrey F. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)] [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Whiting, Bruce R. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)] [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States); O’Sullivan, Joseph A. [Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130 (United States)] [Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130 (United States); Politte, David G. [Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110 (United States)] [Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110 (United States); Klahr, Paul H. [Philips Healthcare, 595 Miner Rd., Highland Hts., Ohio 44143 (United States)] [Philips Healthcare, 595 Miner Rd., Highland Hts., Ohio 44143 (United States)

2013-12-15

249

On the Doppler effect for photons in rotating systems  

NASA Astrophysics Data System (ADS)

The analysis of the Doppler effect for photons in rotating systems, studied using the Mössbauer effect, confirms the general conclusions of a previous paper dedicated to experiments with photons emitted/absorbed by atoms/nuclei in inertial flight. The wave theory of light is so deeply rooted that it continues to be applied to describe phenomena in which the fundamental entities at work are discrete (photons). The fact that the wave theory of light can describe one aspect of these phenomena should not overshadow two issues: the corpuscular theory of light, first applied to the Doppler effect for photons by Schrödinger in 1922, is by far more complete since it describes all of the features of the studied phenomena; the wave theory can only be used when the number of photons at work is statistically significant. This disregarding of basic methodological criteria may appear to be a minor fault. However, the historical development of quantum physics shows that the predominance of the wave theory of radiation, beyond its natural application domain, has hampered the reorientation toward the photon description of the underlying phenomena.

Giuliani, Giuseppe

2014-03-01

250

Reliable source of conditional states from single-mode pulsed thermal fields by multiple-photon subtraction  

SciTech Connect

We demonstrate the effect of multiple-photon subtraction on the generation of conditional states in the pulsed regime. Our experimental scheme relies on a beam splitter (BS) and a pair of linear photodetectors that are able to resolve up to tens of photons. We use a single-mode thermal field at the input port of the BS to test the reliability of our scheme, and we show good agreement with the theory by fully characterizing the conditional outgoing states in terms of photon-number statistics and non-Gaussianity.

Allevi, A. [Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia U.d.R. Como, I-22100 Como (Italy); Andreoni, A. [Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia U.d.R. Como, I-22100 Como (Italy); Dipartimento di Fisica e Matematica, Universita degli Studi dell'Insubria, I-22100 Como (Italy); Bondani, M. [Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia U.d.R. Como, I-22100 Como (Italy); Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, I-22100 Como (Italy); Genoni, M. G.; Olivares, S. [Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia U.d.R. Milano Universita, I-20133 Milano (Italy); Dipartimento di Fisica, Universita degli Studi di Milano, I-20133 Milano (Italy)

2010-07-15

251

Cancer Statistics  

MedlinePLUS

... 1975-2011 Did You Know? Video Series Cancer Statistics Understanding Cancer Statistics Learn definitions of statistical terms, how cancer statistics are used, and how population-based cancer statistics ...

252

A single-photon server with just one atom MARKUS HIJLKEMA1  

E-print Network

LETTERS A single-photon server with just one atom MARKUS HIJLKEMA1 , BERNHARD WEBER1 , HOLGER P the photon-emission statistics and, second, guarantee the subsequent performance as a single-photon server

Loss, Daniel

253

Multi-Photon Quantum Interferometry  

Microsoft Academic Search

Based on the investigation of multi-photon entanglement, as produced by stimulated parametric down-conversion, a technique is presented to create heralded ``noon'' states. The relevance for interferometry will be discussed. Furthermore we explored the use of photon-number resolving detectors in Mach-Zehnder type of interferometers. Our current detectors can distinguish 0, 1, 2, to7, photon impacts. Although the overall collection and detection

Dirk Bouwmeester

2007-01-01

254

Statistics of protein-DNA binding and the total number of binding sites for a transcription factor in the mammalian genome  

Microsoft Academic Search

BACKGROUND: Transcription factor (TF)-DNA binding loci are explored by analyzing massive datasets generated with application of Chromatin Immuno-Precipitation (ChIP)-based high-throughput sequencing technologies. These datasets suffer from a bias in the information about binding loci availability, sample incompleteness and diverse sources of technical and biological noises. Therefore adequate mathematical models of ChIP-based high-throughput assay(s) and statistical tools are required for a

Vladimir A Kuznetsov; Onkar Singh; Piroon Jenjaroenpun

2010-01-01

255

Dow Corning photonics: the silicon advantage in automotive photonics  

Microsoft Academic Search

The Automotive Market offers several opportunities for Dow Corning to leverage the power of silicon-based materials. Dow Corning Photonics Solutions has a number of developments that may be attractive for the emergent photonics needs in automobiles, building on 40 years of experience as a leading Automotive supplier with a strong foundation of expertise and an extensive product offering- from encapsulents

Terry V. Clapp; Rene Paquet; Ann Norris; Babette Pettersen

2005-01-01

256

International Statistical Institute - Glossary of Statistical Terms  

NSDL National Science Digital Library

This site shows the International Statistical Institutes alphabetical list of technical terms showing the translation in a number of languages. The page covers a myriad of different terms and our translated into many languages such as: English, French, German, Dutch, Italian, Spanish, Catalan, Portuguese, Romanian, Danish, Norwegian, Swedish, Greek and many more. This is a nice reference site for anyone interested in statistics.

257

VOLUME 79, NUMBER 26 P HY S I CA L REV I EW L E T T ER S 29 DECEMBER 1997 Coherent Control of Spontaneous Emission near a Photonic Band Edge  

E-print Network

of Spontaneous Emission near a Photonic Band Edge: A Single­Atom Optical Memory Device Tran Quang, Mesfin demonstrate coherent control of spontaneous emission from a three­level atom with one resonant frequency near the edge of a photonic band gap. As a result of quantum interference and photon localization, spontaneous

John, Sajeev

258

VOLUME 79, NUMBER 26 P H Y S I C A L R E V I E W L E T T E R S 29 DECEMBER 1997 Coherent Control of Spontaneous Emission near a Photonic Band Edge  

E-print Network

of Spontaneous Emission near a Photonic Band Edge: A Single-Atom Optical Memory Device Tran Quang, Mesfin demonstrate coherent control of spontaneous emission from a three-level atom with one resonant frequency near the edge of a photonic band gap. As a result of quantum interference and photon localization, spontaneous

John, Sajeev

259

The photon  

NASA Astrophysics Data System (ADS)

There are no TEM waves, only photons. Lets build a photon, using a radio antenna. A short antenna (2L<< ?) simplifies the calculation, letting B fall off everywhere as 1/r^2. The Biot-Savart law finds B = (?0/4?)(LI0/r^2)??t. The magnetic flux thru a semi-circle of radius ?/2 is set equal to the flux quantum h/e, determining the needed source strength, LI0. From this, one can integrate the magnetic energy density over a sphere of radius ?/2 and finds it to be 1.0121 hc/?. Pretty close. A B field collapses when the current ceases, but the photon evades this by creating a ?0E / t displacement current at center that fully supports the toroidal B assembly as it moves at c. This E=vxB arises because the photon moves at c. Stopped, a photon decays. At every point along the photon's path, an observer will note a transient oscillation of an E field. This sources the EM ``guiding wave'', carrying little or no energy and expanding at c. At the head of the photon, all these spherical guiding waves gather ``in-phase'' as a planar wavefront. This model speaks to all the many things we know about light. The photon is tiny, but its guiding wave is huge.

Collins, Russell L.

2009-10-01

260

Chalcogenide photonics  

Microsoft Academic Search

The unique and striking material properties of chalcogenide glasses have been studied for decades, providing applications in the electronics industry, imaging and more recently in photonics. This Review summarizes progress in photonic devices that exploit the unique optical properties of chalcogenide glasses for a range of important applications, focusing on recent examples in mid-infrared sensing, integrated optics and ultrahigh-bandwidth signal

Benjamin J. Eggleton; Barry Luther-Davies; Kathleen Richardson

2011-01-01

261

Folding Photons  

SciTech Connect

Scientists have shown that wrinkles and folds can be used to maximize the absorption of low-energy photons by efficiently redirecting them into a thin absorbing film. This inexpensive technique for structuring photonic substrates could be used to increase the efficiency of many organic photovoltaic cells.

Gregg, B. A.; van de Lagemaat, J.

2012-05-01

262

Photoelectron statistics  

NASA Astrophysics Data System (ADS)

Using Burgess's variance theorem, it is shown that at binomial transitional characteristics, variances of photons and photoelectrons have identical functional form when photons have negative-binomial or Poisson distribution function. By direct calculation it is obtained that in this cases photoelectrons distribution function reproduces that of photons that is photoelectrons distribution function has negative-binomial or Poisson form.

Serebrennikov, Pavel S.

1999-06-01

263

PHOTON2  

NSDL National Science Digital Library

Funded through a three-year grant from the Advanced Technological Education (ATE) program of the National Science Foundation (NSF), Project PHOTON2 builds on the highly successful "Alliance" model developed through the previous Project PHOTON.In both projects, educators from several geographic locations (four to six regions nationally) are brought together to facilitate photonics technology education at their institutions that is intelligently developed and seamlessly articulated. The âÂÂAlliancesâ consist of four to six participants per region, including high school and two- and four-year college science, technology, engineering, and math instructors, as well as their institution's career and admissions counselors. On this site, visitors will find curriculum materials, information about the PHOTON2 laboratory kit and careers in photonics, links to external tutorials and applets, and societies and organizations. Visitors can also find out more about the project, its team, newsletter, conference papers, workshop, and a distance learning course for educators.

2010-10-07

264

Strong photon antibunching of symmetric and antisymmetric modes in weakly nonlinear photonic molecules  

NASA Astrophysics Data System (ADS)

We study the photon statistics of symmetric and antisymmetric modes in a photonic molecule consisting of two linearly coupled nonlinear cavity modes. Our calculations show that strong photon antibunching of both symmetric and antisymmetric modes can be obtained even when the nonlinearity in the photonic molecule is weak. The strong antibunching effect results from the destructive interference between different paths for two-photon excitation. Moreover, we find that the optimal frequency detunings for strong photon antibunching in the symmetric and antisymmetric modes are linearly dependent on the coupling strength between the cavity modes in the photonic molecule. This implies that the photonic molecules can be used to generate tunable single-photon sources by tuning the values of the coupling strength between the cavity modes with weak nonlinearity.

Xu, Xun-Wei; Li, Yong

2014-09-01

265

Statistical Laboratory & Department of Statistics  

E-print Network

Statistical Laboratory & Department of Statistics Annual Report July 1, 2005 to December 31, 2006...............................................33 Statistical Computing Section ......................................34 CSSM and statistical methodology in the nutritional sciences. We were also very pleased to secure a permanent lecturer

266

On the Doppler effect for photons in rotating systems  

E-print Network

The analysis of the Doppler effect for photons in rotating systems, studied using the M\\"ossbauer effect, confirms the general conclusions of a previous paper dedicated to experiments with photons emitted/absorbed by atoms/nuclei in inertial flight. The wave theory of light is so deeply rooted that it has been--and currently is--applied to describe phenomena in which the fundamental entities at work are discrete (photons). The fact that the wave theory of light can describe one aspect of these phenomena can not overshadow two issues: the corpuscular theory of light, firstly applied to the Doppler effect for photons by Schr\\"odinger in 1922, is by far more complete since it describes all the features of the studied phenomena; the wave theory can be used only when the number of photons at work is statistically significant. The disregard of basic methodological criteria may appear as a minor fault. However, the historical development of quantum physics shows that the predominance of the wave theory of radiation,...

Giuliani, Giuseppe

2015-01-01

267

Photon statistics and polarization correlations at telecommunications  

E-print Network

. Harris, "Subnatural linewidth biphotons with controllable temporal length," Phys. Rev. Lett. 100, 183603 (2008). 8. T. Chaneli`ere, D. N. Matsukevich, S. D. Jenkins, T. A. B. Kennedy, M. S. Chapman, and A

Orozco, Luis A.

268

On Realization of a Cavity-QED Laser Emitting a Highly Sub-Poissonian, Anti-Bunched Beam of Photons in a CW Fashion  

NASA Astrophysics Data System (ADS)

We propose a feedback scheme to control the photon statistics in a micromaser/laser cavity, using the system output as the control signal, which generates a highly nonclassical field whose Mandel-Q parameter is even lower than ?0.9 and mean photon number much greater than unity. We demonstrate that the so-obtained system constitutes a continuous-wave (CW) quasi-Fock state source, the emission of which exhibits a sub-Poissonian photocount distribution as well as the photon anti-bunching property.

Chough, Young-Tak

2014-05-01

269

A Photon Interference Detector with Continuous Display.  

ERIC Educational Resources Information Center

Describes an apparatus which attempts to give a direct visual impression of the random detection of individual photons coupled with the recognition of the classical intensity distribution as a result of fairly high proton statistics. (Author/GA)

Gilmore, R. S.

1978-01-01

270

Extending single-photon optimized superconducting transition edge sensors beyond the single-photon counting regime.  

PubMed

Typically, transition edge sensors resolve photon number of up to 10 or 20 photons, depending on the wavelength and TES design. We extend that dynamic range up to 1000 photons, while maintaining sub-shot noise detection process uncertainty of the number of detected photons and beyond that show a monotonic response up to ? 6 · 10(6) photons in a single light pulse. This mode of operation, which heats the sensor far beyond its transition edge into the normal conductive regime, offers a technique for connecting single-photon-counting measurements to radiant-power measurements at picowatt levels. Connecting these two usually incompatible operating regimes in a single detector offers significant potential for directly tying photon counting measurements to conventional cryogenic radiometric standards. In addition, our measurements highlight the advantages of a photon-number state source over a coherent pulse source as a tool for characterizing such a detector. PMID:23188345

Gerrits, Thomas; Calkins, Brice; Tomlin, Nathan; Lita, Adriana E; Migdall, Alan; Mirin, Richard; Nam, Sae Woo

2012-10-01

271

Resonant photonic States in coupled heterostructure photonic crystal waveguides.  

PubMed

In this paper, we study the photonic resonance states and transmission spectra of coupled waveguides made from heterostructure photonic crystals. We consider photonic crystal waveguides made from three photonic crystals A, B and C, where the waveguide heterostructure is denoted as B/A/C/A/B. Due to the band structure engineering, light is confined within crystal A, which thus act as waveguides. Here, photonic crystal C is taken as a nonlinear photonic crystal, which has a band gap that may be modified by applying a pump laser. We have found that the number of bound states within the waveguides depends on the width and well depth of photonic crystal A. It has also been found that when both waveguides are far away from each other, the energies of bound photons in each of the waveguides are degenerate. However, when they are brought close to each other, the degeneracy of the bound states is removed due to the coupling between them, which causes these states to split into pairs. We have also investigated the effect of the pump field on photonic crystal C. We have shown that by applying a pump field, the system may be switched between a double waveguide to a single waveguide, which effectively turns on or off the coupling between degenerate states. This reveals interesting results that can be applied to develop new types of nanophotonic devices such as nano-switches and nano-transistors. PMID:20672066

Cox, Jd; Sabarinathan, J; Singh, Mr

2010-01-01

272

Photon generator  

DOEpatents

A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

Srinivasan-Rao, Triveni (Shoreham, NY)

2002-01-01

273

Third-order antibunching from an imperfect single-photon source.  

PubMed

We measure second- and third-order temporal coherences, g((2))(?) and g((3))(?1,?2), of an optically excited single-photon source: an InGaAs quantum dot in a microcavity pedestal. Increasing the optical excitation power leads to an increase in the measured count rate, and also an increase in multi-photon emission probability. We show that standard measurements of g((2)) provide limited information about this multi-photon probability, and that more information can be gained by simultaneously measuring g((3)). Experimental results are compared with a simple theoretical model to show that the observed antibunchings are consistent with an incoherent addition of two sources: 1) an ideal single-photon source that never emits multiple photons and 2) a background cavity emission having Poissonian photon number statistics. Spectrally resolved cross-correlation measurements between quantum-dot and cavity modes show that photons from these two sources are largely uncorrelated, further supporting the model. We also analyze the Hanbury Brown-Twiss interferometer implemented with two or three "click" detectors, and explore the conditions under which it can be used to accurately measure g((2))(?) and g((3))(?1,?2). PMID:24663616

Stevens, Martin J; Glancy, Scott; Nam, Sae Woo; Mirin, Richard P

2014-02-10

274

Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector  

NASA Technical Reports Server (NTRS)

The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.

Huntington, Andrew

2013-01-01

275

Multi-Photon Quantum Interferometry  

NASA Astrophysics Data System (ADS)

Based on the investigation of multi-photon entanglement, as produced by stimulated parametric down-conversion, a technique is presented to create heralded ``noon'' states. The relevance for interferometry will be discussed. Furthermore we explored the use of photon-number resolving detectors in Mach-Zehnder type of interferometers. Our current detectors can distinguish 0, 1, 2, to7, photon impacts. Although the overall collection and detection efficiency of photons is well below unity (about 0.3) the photon number resolving property is still very useful if combined with coherent input states since those state are eigenstates of the photon annihilation operator. First we analyze the coherent state interferometer with a single photon-number resolving detector, revealing the strong non-linear response of an interferometer in the case of Fock-state projection. Second, we use two such detectors together with a Baysian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift. This protocol is unbiased and saturates the Cramer-Rao phase uncertainty bound and, therefore, is an optimal phase estimation strategy. As a final topic it will be shown how quantum interferometry combined with micromechanical structures can be used to investigate quantum superpositions and quantum decoherence of macroscopic objects.

Bouwmeester, Dirk

2007-06-01

276

32. Statistics 1 32. STATISTICS  

E-print Network

32. Statistics 1 32. STATISTICS Revised September 2007 by G. Cowan (RHUL). This chapter gives an overview of statistical methods used in High Energy Physics. In statistics, we are interested in using's validity or to determine the values of its parameters. There are two main approaches to statistical

Masci, Frank

277

Department of Statistics STATISTICS COLLOQUIUM  

E-print Network

Department of Statistics STATISTICS COLLOQUIUM ERIC KOLACZYK Department of Statistics Boston University Statistical Analysis of Network Data: (Re)visiting the Foundations MONDAY, October 13, 2014, at 4, statistical methods and modeling have been central to these efforts. But how well do we truly understand

278

Extragalactic Millimeter-wave Point-source Catalog, Number Counts and Statistics from 771 deg2 of the SPT-SZ Survey  

NASA Astrophysics Data System (ADS)

We present a point-source catalog from 771 deg2 of the South Pole Telescope Sunyaev-Zel'dovich survey at 95, 150, and 220 GHz. We detect 1545 sources above 4.5? significance in at least one band. Based on their relative brightness between survey bands, we classify the sources into two populations, one dominated by synchrotron emission from active galactic nuclei, and one dominated by thermal emission from dust-enshrouded star-forming galaxies. We find 1238 synchrotron and 307 dusty sources. We cross-match all sources against external catalogs and find 189 unidentified synchrotron sources and 189 unidentified dusty sources. The dusty sources without counterparts are good candidates for high-redshift, strongly lensed submillimeter galaxies. We derive number counts for each population from 1 Jy down to roughly 11, 4, and 11 mJy at 95, 150, and 220 GHz. We compare these counts with galaxy population models and find that none of the models we consider for either population provide a good fit to the measured counts in all three bands. The disparities imply that these measurements will be an important input to the next generation of millimeter-wave extragalactic source population models.

Mocanu, L. M.; Crawford, T. M.; Vieira, J. D.; Aird, K. A.; Aravena, M.; Austermann, J. E.; Benson, B. A.; Béthermin, M.; Bleem, L. E.; Bothwell, M.; Carlstrom, J. E.; Chang, C. L.; Chapman, S.; Cho, H.-M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W. B.; George, E. M.; Halverson, N. W.; Harrington, N.; Hezaveh, Y.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hrubes, J. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Lueker, M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mohr, J. J.; Montroy, T. E.; Natoli, T.; Padin, S.; Plagge, T.; Pryke, C.; Rest, A.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Spilker, J. S.; Stalder, B.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Switzer, E. R.; Vanderlinde, K.; Williamson, R.

2013-12-01

279

MCNP: Photon benchmark problems  

SciTech Connect

The recent widespread, markedly increased use of radiation transport codes has produced greater user and institutional demand for assurance that such codes give correct results. Responding to these pressing requirements for code validation, the general purpose Monte Carlo transport code MCNP has been tested on six different photon problem families. MCNP was used to simulate these six sets numerically. Results for each were compared to the set's analytical or experimental data. MCNP successfully predicted the analytical or experimental results of all six families within the statistical uncertainty inherent in the Monte Carlo method. From this we conclude that MCNP can accurately model a broad spectrum of photon transport problems. 8 refs., 30 figs., 5 tabs.

Whalen, D.J.; Hollowell, D.E.; Hendricks, J.S.

1991-09-01

280

Natural photonic crystals  

NASA Astrophysics Data System (ADS)

Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

Vigneron, Jean Pol; Simonis, Priscilla

2012-10-01

281

Computational Statistics Canonical Forest  

E-print Network

Computational Statistics Canonical Forest --Manuscript Draft-- Manuscript Number: COST-D-12-00160R3 Full Title: Canonical Forest Article Type: Original Paper Keywords: Canonical linear discriminant analysis; Classification; Ensemble; Linear discriminant analysis; Rotation Forest Corresponding Author

Ahn, Hongshik

282

Photon-photon scattering in collisions of intense laser pulses  

NASA Astrophysics Data System (ADS)

A scenario for measuring the predicted processes of vacuum elastic photon-photon scattering and four-wave mixing with intense modern lasers is investigated. The numbers of measurable scattered photons are calculated for the collision of two, Gaussian-focused, pulsed lasers. It is shown that a single intense 10 PW optical laser beam split into two counter-propagating pulses is sufficient for measuring the elastic process. Moreover, when these pulses are sub-cycle, by also considering the collision of two sech pulses, the results suggest that the frequency-shifting, four-wave mixing process should be measurable too.

King, B.; Keitel, C. H.

2012-10-01

283

Statistics Canada = Statistique Canada  

NSDL National Science Digital Library

Statistics Canada, a national statistical agency, offers this excellent collection on the economic and social conditions in Canada. Statistical information is divided into four broad topics: The Land, The People, The Economy, and the State. Within each are a number of sub-topics which offer lists of statistical tables. Newly released data, research papers, downloadable publications (Adobe Acrobat [.pdf] format only), and notices of seminars and conferences are featured in addition to The Daily, a collection of the latest news releases and publications from the agency. This site can be viewed in English or French. Note that there is a combination of free and fee based material available.

1997-01-01

284

Green photonics  

NASA Astrophysics Data System (ADS)

Photonics, the broad merger of electronics with the optical sciences, encompasses such a wide swath of technology that its impact is almost universal in our everyday lives. This is a broad overview of some aspects of the industry and their contribution to the ‘green’ or environmental movement. The rationale for energy conservation is briefly discussed and the impact of photonics on our everyday lives and certain industries is described. Some opinions from industry are presented along with market estimates. References are provided to some of the most recent research in these areas.

Quan, Frederic

2012-02-01

285

Topological photonics  

NASA Astrophysics Data System (ADS)

The application of topology, the mathematics of conserved properties under continuous deformations, is creating a range of new opportunities throughout photonics. This field was inspired by the discovery of topological insulators, in which interfacial electrons transport without dissipation, even in the presence of impurities. Similarly, the use of carefully designed wavevector-space topologies allows the creation of interfaces that support new states of light with useful and interesting properties. In particular, this suggests unidirectional waveguides that allow light to flow around large imperfections without back-reflection. This Review explains the underlying principles and highlights how topological effects can be realized in photonic crystals, coupled resonators, metamaterials and quasicrystals.

Lu, Ling; Joannopoulos, John D.; Solja?i?, Marin

2014-11-01

286

Photonic Floquet topological insulators.  

PubMed

Topological insulators are a new phase of matter, with the striking property that conduction of electrons occurs only on their surfaces. In two dimensions, electrons on the surface of a topological insulator are not scattered despite defects and disorder, providing robustness akin to that of superconductors. Topological insulators are predicted to have wide-ranging applications in fault-tolerant quantum computing and spintronics. Substantial effort has been directed towards realizing topological insulators for electromagnetic waves. One-dimensional systems with topological edge states have been demonstrated, but these states are zero-dimensional and therefore exhibit no transport properties. Topological protection of microwaves has been observed using a mechanism similar to the quantum Hall effect, by placing a gyromagnetic photonic crystal in an external magnetic field. But because magnetic effects are very weak at optical frequencies, realizing photonic topological insulators with scatter-free edge states requires a fundamentally different mechanism-one that is free of magnetic fields. A number of proposals for photonic topological transport have been put forward recently. One suggested temporal modulation of a photonic crystal, thus breaking time-reversal symmetry and inducing one-way edge states. This is in the spirit of the proposed Floquet topological insulators, in which temporal variations in solid-state systems induce topological edge states. Here we propose and experimentally demonstrate a photonic topological insulator free of external fields and with scatter-free edge transport-a photonic lattice exhibiting topologically protected transport of visible light on the lattice edges. Our system is composed of an array of evanescently coupled helical waveguides arranged in a graphene-like honeycomb lattice. Paraxial diffraction of light is described by a Schrödinger equation where the propagation coordinate (z) acts as 'time'. Thus the helicity of the waveguides breaks z-reversal symmetry as proposed for Floquet topological insulators. This structure results in one-way edge states that are topologically protected from scattering. PMID:23579677

Rechtsman, Mikael C; Zeuner, Julia M; Plotnik, Yonatan; Lumer, Yaakov; Podolsky, Daniel; Dreisow, Felix; Nolte, Stefan; Segev, Mordechai; Szameit, Alexander

2013-04-11

287

Reform by the Numbers.  

ERIC Educational Resources Information Center

Although numbers such as average test scores or dropout rates can capture part of a school system's success or failure, school statistics seldom tell the whole story. School board members should realize that numbers might measure compliance or process, rather than improvement. Also, improvements in numbers might reflect changes in assessment…

Hanford, Terry; White, Kathleen

1991-01-01

288

RIKENRESEARCH FEBRUARY2014 VOLUME 9 NUMBER 2  

E-print Network

focused laser beam can generate high-energy radiation and accelerate particles up to gigaelectron- volt in a number of different directions: high-energy photonics, quantum metrology, nanophotonics and terahertz photonics. The earliest lasers emitted photons with the energy of about 1 electronvolt, but today a strongly

Fukai, Tomoki

289

GRB 110709A, 111117A, AND 120107A: FAINT HIGH-ENERGY GAMMA-RAY PHOTON EMISSION FROM FERMI-LAT OBSERVATIONS AND DEMOGRAPHIC IMPLICATIONS  

SciTech Connect

Launched on 2008 June 11, the Large Area Telescope (LAT) instrument on board the Fermi Gamma-ray Space Telescope has provided a rare opportunity to study high-energy photon emission from gamma-ray bursts (GRBs). Although the majority of such events (27) have been identified by the Fermi-LAT Collaboration, four were uncovered by using more sensitive statistical techniques. In this paper, we continue our earlier work by finding three more GRBs associated with high-energy photon emission, GRB 110709A, 111117A, and 120107A. To systematize our matched filter approach, a pipeline has been developed to identify these objects in nearly real time. GRB 120107A is the first product of this analysis procedure. Despite the reduced threshold for identification, the number of GRB events has not increased significantly. This relative dearth of events with low photon number prompted a study of the apparent photon number distribution. We find an extremely good fit to a simple power law with an exponent of -1.8 {+-} 0.3 for the differential distribution. As might be expected, there is a substantial correlation between the number of lower energy photons detected by the Gamma-ray Burst Monitor (GBM) and the number observed by LAT. Thus, high-energy photon emission is associated with some but not all of the brighter GBM events. Deeper studies of the properties of the small population of high-energy emitting bursts may eventually yield a better understanding of these entire phenomena.

Zheng Weikang; Akerlof, Carl W.; McKay, Timothy A. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Pandey, Shashi B. [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263129 (India); Zhang Binbin [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Zhang Bing [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States); Sakamoto, Takanori, E-mail: zwk@umich.edu [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-01

290

Photonic Devices  

NASA Astrophysics Data System (ADS)

Covering every major photonic device, this textbook strikes a careful balance between theoretical and practical concepts. The devices it covers include optical fibers, couplers, electro-optic devices, magneto-optic devices, lasers and photodetectors. The book is well-suited as a text for senior undergraduate and graduate courses, as well as a device-driven engineering reference for professionals.

Liu, Jia-Ming

2005-05-01

291

Photon-photon collisions via relativisitic mirrors  

SciTech Connect

Photon-photon scattering at low energies has been predicted theoretically for many years. However, due to the extremely small cross section there has been no experimental confirmation of this. Due to the rapid increase in laser irradiances and projected peak irradiances in planned facilities regimes could be reached where photon-photon scattering could be experimentally observed. We will first review basic aspects of photon-photon collisions concentrating on the calculation of the photon-photon scattering cross section. Then we will discuss the possibilities for observing these phenomena in ultra-high irradiance laser-plasma interactions involving relativistic mirrors.

Koga, James K. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan)

2012-07-11

292

Di-photon and photon + b/c production cross sections at Ecm = 1.96- TeV  

SciTech Connect

Measurements of the di-photon cross section have been made in the central region and are found to be in good agreement with NLO QCD predictions. The cross section of events containing a photon and additional heavy flavor jet have also been measured, as well as the ratio of photon + b to photon + c. The statistically limited sample shows good agreement with Leading Order predictions.

Gajjar, Anant; /Liverpool U.

2005-05-01

293

Emitters of N-photon bundles.  

PubMed

Controlling the ouput of a light emitter is one of the basic tasks of photonics, with landmarks such as the laser and single-photon sources. The development of quantum applications makes it increasingly important to diversify the available quantum sources. Here, we propose a cavity QED scheme to realize emitters that release their energy in groups, or "bundles" of N photons, for integer N. Close to 100% of two-photon emission and 90% of three-photon emission is shown to be within reach of state of the art samples. The emission can be tuned with system parameters so that the device behaves as a laser or as a N-photon gun. The theoretical formalism to characterize such emitters is developed, with the bundle statistics arising as an extension of the fundamental correlation functions of quantum optics. These emitters will be useful for quantum information processing and for medical applications. PMID:25013456

Muñoz, C Sánchez; Del Valle, E; Tudela, A González; Müller, K; Lichtmannecker, S; Kaniber, M; Tejedor, C; Finley, J J; Laussy, F P

2014-07-01

294

Emitters of N-photon bundles  

PubMed Central

Controlling the ouput of a light emitter is one of the basic tasks of photonics, with landmarks such as the laser and single-photon sources. The development of quantum applications makes it increasingly important to diversify the available quantum sources. Here, we propose a cavity QED scheme to realize emitters that release their energy in groups, or “bundles” of N photons, for integer N. Close to 100% of two-photon emission and 90% of three-photon emission is shown to be within reach of state of the art samples. The emission can be tuned with system parameters so that the device behaves as a laser or as a N-photon gun. The theoretical formalism to characterize such emitters is developed, with the bundle statistics arising as an extension of the fundamental correlation functions of quantum optics. These emitters will be useful for quantum information processing and for medical applications. PMID:25013456

Muñoz, C. Sánchez; del Valle, E.; Tudela, A. González; Müller, K.; Lichtmannecker, S.; Kaniber, M.; Tejedor, C.; Finley, J.J.; Laussy, F.P.

2014-01-01

295

Photon collider at TESLA  

E-print Network

High energy photon colliders (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural addition to e+e- linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the gamma-gamma luminosity luminosity in the high energy part of spectrum can reach (1/3)L_{e+e-}. Typical cross sections of interesting processes in gamma-gamma collisions are higher than those in e+e- collisions by about one order of magnitude, so the number of events in gamma-gamma collisions will be more than that in e+e- collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ``an optical storage ring (optical trap)'' with diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based at TESLA, its possible parameters and existing problems.

Valery Telnov

2001-03-06

296

Statistics Anxiety and Business Statistics: The International Student  

ERIC Educational Resources Information Center

Does the international student suffer from statistics anxiety? To investigate this, the Statistics Anxiety Rating Scale (STARS) was administered to sixty-six beginning statistics students, including twelve international students and fifty-four domestic students. Due to the small number of international students, nonparametric methods were used to…

Bell, James A.

2008-01-01

297

STATISTICS AND MODELING Unique Numbers: 04605  

E-print Network

://courses.utexas.edu Syllabus, lecture notes, homework assignments, and other course materials will be available within are distracting other students I will ask you to leave the classroom. Grading Policy The course grade is comprised of the following elements: Homework ­ 20% Four exams ­ 80% (20% per exam) There is no predetermined grade

Ghosh, Joydeep

298

A new analysis method of single molecule fluorescence using series of photon arrival times: theory and experiment  

NASA Astrophysics Data System (ADS)

Up to now, single molecule fluorescence experiments were performed by dividing the time into a set of intervals and to observe the number of fluorescence photons arriving in each interval. It is obvious that the detected photons carry less information than the arrival times of the photons themselves. From the arrival times, one can still calculate the number of photons in any user-defined interval; whereas, when only the number of photons in an interval are recorded, information about their positions in time is lost. Therefore, we present a new analysis method of single molecule fluorescence data based on the positions in time of the detected fluorescence photons. We derive mathematically different statistical characteristics describing the single molecule fluorescence experiment assuming an immobilized molecule. The theory of point processes using the generating functionals formalism is ideally suited for a consistent description, linking the statistical characteristics of the excitation and detected photons to the statistical characteristics of the single motionless molecule. We then use computer-generated data sets mimicking the single molecule fluorescence experiment to explore the parametric estimation of mono- and bi-exponential single molecule impulse response functions (SMIRFs) via the following statistical characteristics: the probability density distributions (pdd) of the single and first photocount time positions in a user-defined detection interval, the probability distribution of the number of photocounts per user-defined detection interval, the time correlation function and the pdd of the time interval between two consecutive photocounts. It is shown that all of the above characteristics ensure a satisfactory recovery of the decay time of mono-exponential SMIRFs for a broad range of excitation intensities and widths of user-defined detection intervals. For bi-exponential SMIRFs, the selection of the experimental conditions is more critical and dependent on the detection procedure. At lower excitation intensities it is advantageous to use the pdds of the single and first photocount time occurrences in the user-defined detection interval. To show the practical usefulness of the new analysis method, series of photon arrival times from immobilized single molecules of DiI and rhodamine 6G were analyzed to estimate triplet lifetimes and intersystem crossing yields.

Novikov, Eugene; Hofkens, Johan; Cotlet, Mircea; Maus, Michael; De Schryver, Frans C.; Boens, Noël

2001-09-01

299

Histoplasmosis Statistics  

MedlinePLUS

... About CDC.gov . Fungal Diseases Share Compartir Histoplasmosis Statistics How common is histoplasmosis? In the United States, ... Risk & Prevention Sources Diagnosis & Testing Treatment Health Professionals Statistics More Resources Blastomycosis Definition Symptoms People at Risk & ...

300

Caregiving Statistics  

MedlinePLUS

Statistics on Family Caregivers and Family Caregiving Caregiving Population Economics of Caregiving Impact on Family Caregiver's Health ... Identified Family Caregivers, 2001. Top State by State Statistics The economic value of family caregiving is detailed ...

301

Statistical Diversions  

ERIC Educational Resources Information Center

As a branch of knowledge, Statistics is ubiquitous and its applications can be found in (almost) every field of human endeavour. In this article, the authors track down the possible source of the link between the "Siren song" and applications of Statistics. Answers to their previous five questions and five new questions on Statistics are presented.

Petocz, Peter; Sowey, Eric

2008-01-01

302

Statistical Diversions  

ERIC Educational Resources Information Center

The term "data snooping" refers to the practice of choosing which statistical analyses to apply to a set of data after having first looked at those data. Data snooping contradicts a fundamental precept of applied statistics, that the scheme of analysis is to be planned in advance. In this column, the authors shall elucidate the statistical

Petocz, Peter; Sowey, Eric

2012-01-01

303

Integrated spatial multiplexing of heralded single-photon sources  

PubMed Central

The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols. PMID:24107840

Collins, M.J.; Xiong, C.; Rey, I.H.; Vo, T.D.; He, J.; Shahnia, S.; Reardon, C.; Krauss, T.F.; Steel, M.J.; Clark, A.S.; Eggleton, B.J.

2013-01-01

304

Term statistics Zipf's law text statistics  

E-print Network

Term statistics Zipf's law text statistics October 20, 2014 text statistics 1 / 19 #12;Term statistics Zipf's law Overview 1 Term statistics 2 Zipf's law text statistics 2 / 19 #12;Term statistics Zipf's law Outline 1 Term statistics 2 Zipf's law text statistics 3 / 19 #12;Term statistics Zipf's law Model

Lu, Jianguo

305

Department of Statistics STATISTICS COLLOQUIUM  

E-print Network

Department of Statistics STATISTICS COLLOQUIUM GOURAB MUKHERJEE Department of Statistics Stanford University Minimax Estimation of High-dimensional Predictive Densities MONDAY, February 11, 2013, at 4:00 PM investments and sports betting, have been undergoing a gradual evolution from point predic- tion towards

Stephens, Matthew

306

Statistical Associates Publishing  

NSDL National Science Digital Library

Statistical Associates Publishing is a creation of Professor Dave Garson and hosts a number of free statistics e-books, and some low-cost Kindle versions as well. Use of the site is password-protected, so visit the Register link first, then continue to download e-books (in PDF form) on topics such as Creating Simulated Datasets, Narrative Analysis, Cluster Analysis, Ordinal Regression, Survey Research, Structural Equation Modeling, and much more.

Garson, G. D.

2009-01-29

307

Optimization of two-photon absorption enhancement in one-dimensional photonic crystals with defect states  

NASA Astrophysics Data System (ADS)

One-dimensional photonic crystals with a defect layer of CdS were fabricated. The observed enhancement of two-photon absorption (TPA) in the CdS layer can be attributed to the intensified optical field confined within the defect layer of the photonic crystal. The results show that the enhancement of TPA coefficient depends basically on the number of periods of the photonic crystal and the defect mode position in the photonic band gap. The observation agrees qualitatively with the expectations of a computation by matrix transfer formulation.

Ma, G. H.; Shen, J.; Rajiv, K.; Tang, S. H.; Zhang, Z. J.; Hua, Z. Y.

2005-03-01

308

Better Randomness with Single Photons  

E-print Network

Randomness is one of the most important resources in modern information science, since encryption founds upon the trust in random numbers. Since it is impossible to prove if an existing random bit string is truly random, it is relevant that they be generated in a trust worthy process. This requires specialized hardware for random numbers, for example a die or a tossed coin. But when all input parameters are known, their outcome might still be predicted. A quantum mechanical superposition allows for provably true random bit generation. In the past decade many quantum random number generators (QRNGs) were realized. A photonic implementation is described as a photon which impinges on a beam splitter, but such a protocol is rarely realized with non-classical light or anti-bunched single photons. Instead, laser sources or light emitting diodes are used. Here we analyze the difference in generating a true random bit string with a laser and with anti-bunched light. We show that a single photon source provides more randomness than even a brighter laser. This gain of usable entropy proves the advantages of true single photons versus coherent input states of light in an experimental implementation. The underlying advantage can be adapted to microscopy and sensing.

Lukas Oberreiter; Ilja Gerhardt

2014-11-13

309

Exact stationary photon distributions due to competition between one- and two-photon absorption and emission  

NASA Astrophysics Data System (ADS)

We consider steady states of the one-mode quantized field interacting with two independent baths, each characterized by the one- and two-photon absorption and emission processes. In the absense of two-photon emission, using an exact analytical solution to the master equation for the diagonal elements of the density matrix in the Fock basis in terms of the confluent hypergeometric function, we obtain simple explicit expressions for the photon distribution function and for the factorial moments in the limiting cases of weak and strong two-photon absorption. If the two-photon absorption is strong enough, the steady state exhibits a sub-Poissonian photon statistics characterizing nonclassical behaviour, but Mandel's 0305-4470/30/16/010/img1-parameter cannot be less 0305-4470/30/16/010/img2. However, the distribution depends essentially on the temperature of the `one-photon bath'. For weak two-photon absorption, the stationary distribution is Gaussian, provided that the temperature of the `one-photon' bath is high enough. For an inversely populated `one-photon' bath, the 0305-4470/30/16/010/img1-parameter is close to 0305-4470/30/16/010/img4. In a generic case of nonzero two-photon emission probability, approximate asymptotic expressions for the factorial moments are found.

Dodonov, V. V.; Mizrahi, S. S.

1997-08-01

310

UCLA Statistics Series  

NSDL National Science Digital Library

The University of California Los Angeles Statistics Series presents a collection of more than 250 preprints covering a wide array of statistical topics, such as descriptive multivariate analysis, advanced linear models, survey construction and analysis, teaching statistics, and much more. The preprints are arranged by paper number only, hence users must browse the entire list to locate relevant items. Approximately half of the full-text preprints are accessible in HTML, .pdf, or postscript formats. To access preprints not available electronically, users must contact the authors of the papers; author addresses are provided.

311

Law of Large Numbers  

NSDL National Science Digital Library

Created by Charles M. Grinstead and J. Laurie Snell of Dartmouth College, this website is part of an online statistics textbook. Topics include: (1) Law of Large Numbers for Discrete Random Variables, (2) Chebyshev Inequality, (3) Law of Averages, (4) Law of Large Numbers for Continuous Random Variables, (5) Monte Carlo Method. There are several examples and exercises that accompany the material.

Grinstead, Charles M.

312

Psychological Statistics  

NSDL National Science Digital Library

This site contains materials for a college level undergraduate statistics course. The approach places emphasis on practical application. Examples are shown with hand computations and with the Minitab statistical program (V13.1). There are a couple of spreadsheets as well. Topics include: frequency distributions, graphing techniques, central tendency, variability, relative standing, correlation, dichotomous variables, continuous variables (1 and 2 sample), ANOVA: one way and two way, and nonparametric statistics.

Plonsky, Mark

2009-01-26

313

Transient photon production in a QGP  

SciTech Connect

We discuss the shortcomings of a formula that has been used in the literature to compute the number of photons emitted by a hot or dense system during a finite time, and show that the transient effects it predicts for the photon rate are unphysical.

Fraga, Eduardo S. [Intituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Gelis, Francois [Service de Physique Theorique, CEA/DSM/Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette cedex (France); Schiff, Dominique [Laboratoire de Physique Theorique, Bat. 210, Universite Paris XI, 91405 Orsay cedex (France)

2004-12-02

314

Lithography system using quantum entangled photons  

NASA Technical Reports Server (NTRS)

A system of etching using quantum entangled particles to get shorter interference fringes. An interferometer is used to obtain an interference fringe. N entangled photons are input to the interferometer. This reduces the distance between interference fringes by n, where again n is the number of entangled photons.

Williams, Colin (Inventor); Dowling, Jonathan (Inventor); della Rossa, Giovanni (Inventor)

2002-01-01

315

Calculating statistical distributions from operator relations: The statistical distributions of various intermediate statistics  

SciTech Connect

In this paper, we give a general discussion on the calculation of the statistical distribution from a given operator relation of creation, annihilation, and number operators. Our result shows that as long as the relation between the number operator and the creation and annihilation operators can be expressed as a{sup †}b=?(N) or N=?{sup ?1}(a{sup †}b), where N, a{sup †}, and b denote the number, creation, and annihilation operators, i.e., N is a function of quadratic product of the creation and annihilation operators, the corresponding statistical distribution is the Gentile distribution, a statistical distribution in which the maximum occupation number is an arbitrary integer. As examples, we discuss the statistical distributions corresponding to various operator relations. In particular, besides the Bose–Einstein and Fermi–Dirac cases, we discuss the statistical distributions for various schemes of intermediate statistics, especially various q-deformation schemes. Our result shows that the statistical distributions corresponding to various q-deformation schemes are various Gentile distributions with different maximum occupation numbers which are determined by the deformation parameter q. This result shows that the results given in much literature on the q-deformation distribution are inaccurate or incomplete. -- Highlights: ? A general discussion on calculating statistical distribution from relations of creation, annihilation, and number operators. ? A systemic study on the statistical distributions corresponding to various q-deformation schemes. ? Arguing that many results of q-deformation distributions in literature are inaccurate or incomplete.

Dai, Wu-Sheng, E-mail: daiwusheng@tju.edu.cn; Xie, Mi, E-mail: xiemi@tju.edu.cn

2013-05-15

316

Multi-photon states and their measurement  

NASA Astrophysics Data System (ADS)

Generation of multi-photon states (such as for instance three- and four-photon states) is one of the most challenging problems of modern quantum optics. In many works the authors claim to have produced such states by means of overlapping photon pairs generated in spontaneous parametric down-conversion (SPDC). Moreover three- and four-photon states generated this way have been used for observing Greenberger-Horne-Zeilinger (GHZ) polarization states testing Bell's inequalities for spin-1 quantum systems preparing W-states and other applications. In this paper we show that the criterion for obtaining three- or four-photon states is the behavior of the corresponding normalized Glauber's correlation function. Calculations carried out for the case of SPDC or even PDC in the stimulated regime demonstrate that these processes are not capable of generating three- or four-photon states: photon statistics reveals typically two-photon behaviour. We suggest a method of measuring higher-order correlation functions in the pulsed regime which allows one to study multi-photon correlations for these and many other processes.

Iskhakov, T. S.; Ivanova, O. A.; Chekhova, Maria V.

2005-06-01

317

Quantum phase transition of light in a one-dimensional photon-hopping-controllable resonator array  

SciTech Connect

We give a concrete experimental scheme for engineering the insulator-superfluid transition of light in a one-dimensional (1D) array of coupled superconducting stripline resonators. In our proposed architecture, the on-site interaction and the photon-hopping rate can be tuned independently by adjusting the transition frequencies of the charge qubits inside the resonators and at the resonator junctions, respectively, which permits us to systematically study the quantum phase transition of light in a complete parameter space. By combining the techniques of photon-number-dependent qubit transition and fast readout of the qubit state using a separate low-Q resonator mode, the statistical property of the excitations in each resonator can be obtained with a high efficiency. An analysis of the various decoherence sources and disorders shows that our scheme can serve as a guide to upcoming experiments involving a small number of coupled resonators.

Wu Chunwang; Gao Ming; Deng Zhijiao; Dai Hongyi; Chen Pingxing; Li Chengzu [College of Science, National University of Defense Technology, Changsha 410073 (China)

2011-10-15

318

Entangled-photon compressive ghost imaging  

SciTech Connect

We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.

Zerom, Petros [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Chan, Kam Wai Clifford [Rochester Optical Manufacturing Company, 1260 Lyell Avenue, Rochester, New York 14606 (United States); Howell, John C. [Department of Physics and Astronomy, University of Rochester, 500 Wilson Boulevard, Rochester, New York 14627 (United States); Boyd, Robert W. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Physics and Astronomy, University of Rochester, 500 Wilson Boulevard, Rochester, New York 14627 (United States); Department of Physics, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5 (Canada)

2011-12-15

319

General displaced SU(1, 1) number states: Revisited  

NASA Astrophysics Data System (ADS)

The most general displaced number states, based on the bosonic and an irreducible representation of the Lie algebra symmetry of su(1, 1) and associated with the Calogero-Sutherland model are introduced. Here, we utilize the Barut-Girardello displacement operator instead of the Klauder-Perelomov counterpart, to construct new kind of the displaced number states which can be classified in nonlinear coherent states regime, too, with special nonlinearity functions. They depend on two parameters, and can be converted into the well-known Barut-Girardello coherent and number states, respectively, depending on which of the parameters equal to zero. A discussion of the statistical properties of these states is included. Significant are their squeezing properties and anti-bunching effects which can be raised by increasing the energy quantum number. Depending on the particular choice of the parameters of the above scenario, we are able to determine the status of compliance with flexible statistics. Major parts of the issue is spent on something that these states, in fact, should be considered as new kind of photon-added coherent states, too. Which can be reproduced through an iterated action of a creation operator on new nonlinear Barut-Girardello coherent states. Where the latter carry, also, outstanding statistical features.

Dehghani, A.

2014-04-01

320

General displaced SU(1, 1) number states: Revisited  

SciTech Connect

The most general displaced number states, based on the bosonic and an irreducible representation of the Lie algebra symmetry of su(1, 1) and associated with the Calogero-Sutherland model are introduced. Here, we utilize the Barut-Girardello displacement operator instead of the Klauder-Perelomov counterpart, to construct new kind of the displaced number states which can be classified in nonlinear coherent states regime, too, with special nonlinearity functions. They depend on two parameters, and can be converted into the well-known Barut-Girardello coherent and number states, respectively, depending on which of the parameters equal to zero. A discussion of the statistical properties of these states is included. Significant are their squeezing properties and anti-bunching effects which can be raised by increasing the energy quantum number. Depending on the particular choice of the parameters of the above scenario, we are able to determine the status of compliance with flexible statistics. Major parts of the issue is spent on something that these states, in fact, should be considered as new kind of photon-added coherent states, too. Which can be reproduced through an iterated action of a creation operator on new nonlinear Barut-Girardello coherent states. Where the latter carry, also, outstanding statistical features.

Dehghani, A., E-mail: alireza.dehghani@gmail.com, E-mail: a-dehghani@tabrizu.ac.ir [Physics Department, Payame Noor University, P.O. Box 19395-3697 Tehran (Iran, Islamic Republic of)

2014-04-15

321

Statistical Diversions  

ERIC Educational Resources Information Center

In this article, the authors focus on hypothesis testing--that peculiarly statistical way of deciding things. Statistical methods for testing hypotheses were developed in the 1920s and 1930s by some of the most famous statisticians, in particular Ronald Fisher, Jerzy Neyman and Egon Pearson, who laid the foundations of almost all modern methods of…

Petocz, Peter; Sowey, Eric

2008-01-01

322

Virtual Photon-Photon Scattering  

NASA Astrophysics Data System (ADS)

Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e+e? ? hadrons. We review the main difficulties that impede such an approach for light-by-light scattering and identify the required ingredients from experiment. Amongst those, the most critical one is the scattering of two virtual photons into meson pairs. We analyze the analytic structure of the process ?*?* ? ?? and show that the usual Muskhelishvili-Omnès representation can be amended in such a way as to remain valid even in the presence of anomalous thresholds.

Hoferichter, Martin; Colangelo, Gilberto; Procura, Massimiliano; Stoffer, Peter

2014-12-01

323

Single photon searches at PEP  

SciTech Connect

The MAC and ASP searches for events with a single photon and no other observed particles are reviewed. New results on the number of neutrino generations and limits on selection, photino, squark and gluino masses from the ASP experiment are presented.

Hollebeek, R.

1985-12-01

324

Inverting the quantum cloning of photons  

E-print Network

We propose an experiment where a photon is first cloned using stimulated parametric down-conversion, making many (imperfect) copies, and then the cloning transformation is inverted, regenerating the original photon while destroying the copies. Focusing on the case where the initial photon is entangled with another photon, we study the conditions under which entanglement can be proven in the final state. The proposed experiment would provide a clear demonstration that quantum information is preserved in phase-covariant quantum cloning. It would furthermore allow an experimental proof for micro-macro entanglement in the intermediate multi-photon state. Finally it might form the basis of a quantum detection technique for small differences in transmission (e.g. in low-contrast biological samples), whose sensitivity scales better with the number of photons used than a classical transmission measurement.

Raeisi, Sadegh; Simon, Christoph

2011-01-01

325

Path entangled photons from parametric down-conversion  

Microsoft Academic Search

Using stimulated parametric down-conversion, we propose a method for generating multiphoton path entanglement. By a special coincidence detection at one down-converted arm, the photons of the second arm non-locally bunch into the desired state. Experimental demonstration for the case of two photons is presented, as well as how to extend the scheme to any number of photons.

Hagai Eisenberg; J. F. Hodelin; G. Khoury; D. Bouwmeester

2005-01-01

326

Two-photon pattern in a second-order interference  

Microsoft Academic Search

An interferometric arrangement utilizing a pair of twin photons, generated by parametric down-conversion, is devised to show second-order interferences revealing de Broglie's wavelength of the photon pair as a whole and the Pancharatnam phase depending on the number of photons. This proposed experiment utilizes the phenomenon ``induced coherence without stimulated emission'' to generate a coherent superposition of states distinct from

H. H. Arnaut; G. A. Barbosa

1998-01-01

327

Photon-counting techniques with silicon avalanche photodiodes  

Microsoft Academic Search

Silicon avalanche photodiodes (APD) have been used for photon counting for a number of years. This paper reviews their properties and the associated electronics required for photon counting in the Geiger mode. Significant improvements are reported in overall photon detection efficiencies (approaching 75% at 633 nm), and timing jitter (under 200 ps) achieved at high over-voltages (20 - 30 V).

Henri Dautet; Pierre Deschamps; Bruno Dion; Andrew D. MacGregor; Darleene MacSween; Robert J. McIntyre; Claude Trottier; Paul P. Webb

1993-01-01

328

A Photon Turnstile Dynamically Regulated by One Atom  

Microsoft Academic Search

Beyond traditional nonlinear optics with large numbers of atoms and photons, qualitatively new phenomena arise in a quantum regime of strong interactions between single atoms and photons. By using a microscopic optical resonator, we achieved such interactions and demonstrated a robust, efficient mechanism for the regulated transport of photons one by one. With critical coupling of the input light, a

Barak Dayan; A. S. Parkins; Takao Aoki; E. P. Ostby; K. J. Vahala; H. J. Kimble

2008-01-01

329

Disordered photonics  

NASA Astrophysics Data System (ADS)

What do lotus flowers have in common with human bones, liquid crystals with colloidal suspensions, and white beetles with the beautiful stones of the Taj Mahal? The answer is they all feature disordered structures that strongly scatter light, in which light waves entering the material are scattered several times before exiting in random directions. These randomly distributed rays interfere with each other, leading to interesting, and sometimes unexpected, physical phenomena. This Review describes the physics behind the optical properties of disordered structures and how knowledge of multiple light scattering can be used to develop new applications. The field of disordered photonics has grown immensely over the past decade, ranging from investigations into fundamental topics such as Anderson localization and other transport phenomena, to applications in imaging, random lasing and solar energy.

Wiersma, Diederik S.

2013-03-01

330

Precision measurements with photon-subtracted or photon-added Gaussian states  

NASA Astrophysics Data System (ADS)

Photon-subtracted and photon-added Gaussian states are amongst the simplest non-Gaussian states that are experimentally available. It is generally believed that they are some of the best candidates to enhance sensitivity in parameter extraction. We derive here the quantum Cramér-Rao bound for such states and find that for large photon numbers photon subtraction or addition only leads to a small correction of the quantum Fisher information (QFI). On the other hand, a divergence of the QFI appears for very small squeezing in the limit of vanishing photon number in the case of photon subtraction, implying an arbitrarily precise measurement with almost no light. However, at least for the standard and experimentally established preparation scheme, the decreasing success probability of the preparation in that limit exactly cancels the divergence, leading to finite sensitivity per square root of Hz, when the duration of the preparation is taken into account.

Braun, Daniel; Jian, Pu; Pinel, Olivier; Treps, Nicolas

2014-07-01

331

Software-based photon counting telemetry receiver for an infrared communications satellite  

NASA Astrophysics Data System (ADS)

Single photon per bit optical communication between ground stations and low earth orbit satellites will enable the secure global distribution of cryptographic keys. The communications satellite AO-40 contains an experimental infra-red payload consisting of a low power 835 nm laser diode transmitter coupled to a small fixed orientation telescope transmitting 400 baud Manchester encoded data [1]. The received signal levels are of the order of 10 photons/bit for an effective telescope aperture of diameter 100 mm [2]. They therefore offer a means of validating models of low photon number OOK signal propagation and detection in the presence of atmospheric turbulence, an issue relevant to free-space quantum communications. This paper describes the design, testing and implementation of a photon counting receiver for AO-40 signals using a Labview software platform to display received data, error statistics, detection and correction (using cyclic redundancy check code CRCC 32), and clock synchronization [3]. Signals are acquired with a 300 mm f/6.3 Schmidt-Cassegrain tracking telescope coupled by 100 micron multimode fibre to a silicon APD photon counting module. References 1. R. Purvinskis, Use of the fixed orientation optical transmitter on AO-40, Internal Report, Centre for Advanced Telecommunications and Quantum Electronics, University of Canberra, 2001. 2. A. Arora, Oscar 40: A Complete Link Analysis, University of Canberra BE (Hons) Report, November 2001. 3. A. Arora, Optical Modulator and Demodulator for the Oscar-40 Satellite, University of Canberra BE Project Report , November 2001.

Arora, Ashish; Edwards, Paul J.

2004-01-01

332

Compressive Object Tracking using Entangled Photons  

E-print Network

We present a compressive sensing protocol that tracks a moving object by removing static components from a scene. The implementation is carried out on a ghost imaging scheme to minimize both the number of photons and the number of measurements required to form a quantum image of the tracked object. This procedure tracks an object at low light levels with fewer than 3% of the measurements required for a raster scan, permitting us to more effectively use the information content in each photon.

Omar S. Magaña-Loaiza; Gregory A. Howland; Mehul Malik; John C. Howell; Robert W. Boyd

2013-06-10

333

Lyapunov exponents for one-dimensional aperiodic photonic bandgap structures  

NASA Astrophysics Data System (ADS)

Existing in the "gray area" between perfectly periodic and purely randomized photonic bandgap structures are the socalled aperoidic structures whose layers are chosen according to some deterministic rule. We consider here a onedimensional photonic bandgap structure, a quarter-wave stack, with the layer thickness of one of the bilayers subject to being either thin or thick according to five deterministic sequence rules and binary random selection. To produce these aperiodic structures we examine the following sequences: Fibonacci, Thue-Morse, Period doubling, Rudin-Shapiro, as well as the triadic Cantor sequence. We model these structures numerically with a long chain (approximately 5,000,000) of transfer matrices, and then use the reliable algorithm of Wolf to calculate the (upper) Lyapunov exponent for the long product of matrices. The Lyapunov exponent is the statistically well-behaved variable used to characterize the Anderson localization effect (exponential confinement) when the layers are randomized, so its calculation allows us to more precisely compare the purely randomized structure with its aperiodic counterparts. It is found that the aperiodic photonic systems show much fine structure in their Lyapunov exponents as a function of frequency, and, in a number of cases, the exponents are quite obviously fractal.

Kissel, Glen J.

2011-10-01

334

Supernova brightening from chameleon-photon mixing  

SciTech Connect

Measurements of standard candles and measurements of standard rulers give an inconsistent picture of the history of the universe. This discrepancy can be explained if photon number is not conserved as computations of the luminosity distance must be modified. I show that photon number is not conserved when photons mix with chameleons in the presence of a magnetic field. The strong magnetic fields in a supernova mean that the probability of a photon converting into a chameleon in the interior of the supernova is high, this results in a large flux of chameleons at the surface of the supernova. Chameleons and photons also mix as a result of the intergalactic magnetic field. These two effects combined cause the image of the supernova to be brightened resulting in a model which fits both observations of standard candles and observations of standard rulers.

Burrage, C. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, Cambridge, CB2 0WA (United Kingdom)

2008-02-15

335

A Very Low Latency Photonic Quantum Random Bit Generator for use in a Loophole Free Bell Test  

E-print Network

A novel type of a quantum random number generator is presented that features characteristics necessary for application in a loophole-free Bell inequality test: (1) a very short latency between the request for a random bit and moment when the bit is generated of (9.8 \\pm 0.2) ns; (2) all physical processes relevant to a generation of a bit happen after the bit request signal; (3) high efficiency of producing a bit upon a request (100\\% by design). Additionally, the generator is characterized by: ability of high bit generation rate, possibility to use a low-efficiency photon detector, a high ratio of number of bits per detected photon (\\approx 2) and simplicity of design. Generated sequences of random bits pass NIST Statistical Test Suite without postprocessing. The generator can be also used for any other purpose where random numbers are needed.

Mario Stip?evi?

2014-07-17

336

Statistics Clinic  

NASA Technical Reports Server (NTRS)

Do you have elevated p-values? Is the data analysis process getting you down? Do you experience anxiety when you need to respond to criticism of statistical methods in your manuscript? You may be suffering from Insufficient Statistical Support Syndrome (ISSS). For symptomatic relief of ISSS, come for a free consultation with JSC biostatisticians at our help desk during the poster sessions at the HRP Investigators Workshop. Get answers to common questions about sample size, missing data, multiple testing, when to trust the results of your analyses and more. Side effects may include sudden loss of statistics anxiety, improved interpretation of your data, and increased confidence in your results.

Feiveson, Alan H.; Foy, Millennia; Ploutz-Snyder, Robert; Fiedler, James

2014-01-01

337

Collaborative Statistics  

NSDL National Science Digital Library

Collaborative Statistics was written by Barbara Illowsky and Susan Dean, faculty members at De Anza College in Cupertino, California. The textbook was developed over several years and has been used in regular and honors-level classroom settings and in distance learning classes. This textbook is intended for introductory statistics courses being taken by students at twoâ and fourâÂÂyear colleges who are majoring in fields other than math or engineering. Intermediate algebra is the only prerequisite. The book focuses on applications of statistical knowledge rather than the theory behind it.

Dean, Susan; Illowsky, Barbara

2009-11-17

338

Rainbow statistics  

E-print Network

Non-commutative quantum field theories and their global quantum group symmetries provide an intriguing attempt to go beyond the realm of standard local quantum field theory. A common feature of these models is that the quantum group symmetry of their Hilbert spaces induces additional structure in the multiparticle states which reflects a non-trivial momentum-dependent statistics. We investigate the properties of this "rainbow statistics" in the particular context of $\\kappa$-quantum fields and discuss the analogies/differences with models with twisted statistics.

Michele Arzano; Dario Benedetti

2008-09-04

339

Universal Characteristics of Fractal Fluctuations in Prime Number Distribution  

E-print Network

The frequency of occurrence of prime numbers at unit number spacing intervals exhibits selfsimilar fractal fluctuations concomitant with inverse power law form for power spectrum generic to dynamical systems in nature such as fluid flows, stock market fluctuations, population dynamics, etc. The physics of long-range correlations exhibited by fractals is not yet identified. A recently developed general systems theory visualises the eddy continuum underlying fractals to result from the growth of large eddies as the integrated mean of enclosed small scale eddies, thereby generating a hierarchy of eddy circulations, or an inter-connected network with associated long-range correlations. The model predictions are as follows: (i) The probability distribution and power spectrum of fractals follow the same inverse power law which is a function of the golden mean. The predicted inverse power law distribution is very close to the statistical normal distribution for fluctuations within two standard deviations from the mean of the distribution. (ii) Fractals signify quantumlike chaos since variance spectrum represents probability density distribution, a characteristic of quantum systems such as electron or photon. (ii) Fractal fluctuations of frequency distribution of prime numbers signify spontaneous organisation of underlying continuum number field into the ordered pattern of the quasiperiodic Penrose tiling pattern. The model predictions are in agreement with the probability distributions and power spectra for different sets of frequency of occurrence of prime numbers at unit number interval for successive 1000 numbers. Prime numbers in the first 10 million numbers were used for the study.

A. M. Selvam

2008-11-12

340

Statistics: Cast Your Vote!  

NSDL National Science Digital Library

Before entering the main portion of this interactive introduction to statistics, visitors will have to answer a few quick questions on polls. It's actually a bit fun, and it serves as a nice introduction to the site. Once visitors are in the main site, they will get the opportunity to learn about statistics through the lens of a mock election. The site contains areas such as "How Random is Random?", "Being Confident", and "What Can Go Wrong". Along with concise explanations of each element of statistics, visitors can also take part in an interactive quiz and some additional polling activities. The site also includes a number of external links for visitors who wish to explore additional topics within the field of statistics.

341

Statistics in pharmacology.  

PubMed

Statistics is an important tool in pharmacological research that is used to summarize (descriptive statistics) experimental data in terms of central tendency (mean or median) and variance (standard deviation, standard error of the mean, confidence interval or range) but more importantly it enables us to conduct hypothesis testing. This is of particular importance when attempting to determine whether the pharmacological effect of one drug is superior to another which clearly has implications for drug development and getting that next paper published in a respectable journal! Therefore, it is essential for pharmacologists to have an understanding of the uses and abuses of statistics. With this in mind, the British Journal of Pharmacology has commissioned a number of review articles to highlight the uses of statistics in experimental design and analysis. PMID:17618311

Spina, D

2007-10-01

342

Engineering Statistics From "Engineering Statistics" , Top &  

E-print Network

Engineering Statistics From "Engineering Statistics" , Top & Wiley, Prapaisri & Pongchanun 2 From "Engineering Statistics" , Top & Wiley, Prapaisri & Pongchanun 3 " "(Sample) (Sampling) ""(Population) " "(Statistics) ""(Parameter) From "Engineering Statistics" , Top & Wiley, Prapaisri

Kovintavewat, Piya

343

Juvenile Court Statistics 1985.  

ERIC Educational Resources Information Center

This report is the 59th in the "Juvenile Court Statistics" series, a series begun in 1929 which serves as the primary source of information on the activities of juvenile courts. It describes the number and characteristics of delinquency and status offense cases disposed during 1985 by courts with juvenile jurisdiction and addresses some important…

Snyder, Howard N.; And Others

344

Application Statistics, 1980.  

ERIC Educational Resources Information Center

Summary statistics for fall 1980 application and registration patterns of applicants wishing to pursue full-time study in first-year places in Ontario universities are presented. The number and percent of increase of applicants are presented for 1973 through 1980 for regular applicants and year five applicants (those who were registered during the…

Council of Ontario Universities, Toronto. Research Div.

345

International Justice Statistics  

NSDL National Science Digital Library

Provides statistical information from the UN Office for Drug Control and Crime Prevention as well as other participating research institutions. Provides links to UN data collections on crime and justice as well as links to justice department websites in a number of foreign countries.

346

Statistical restoration for robust and secure steganography  

Microsoft Academic Search

We investigate data hiding techniques that attempt to defeat steganalysis by restoring the statistics of the composite image to resemble that of the cover. The approach is to reserve a number of host symbols for statistical restoration: host statistics perturbed by data embedding are restored by suitably modifying the symbols from the reserved set. While statistical restoration has broad ap-

Kaushal Solanki; Kenneth Sullivan; Upamanyu Madhow; B. S. Manjunath; Shivkumar Chandrasekaran

2005-01-01

347

Advanced Photon Source.  

E-print Network

enclosure on the nanoprobe beamline. Thank you for taking the time to read our annual report that aims to provide an overview of new capabilities at the Advanced Photon Source (APS) and examples of fascinating scientific research. We are very proud of the accomplishments described here, which are the fruit of dedicated work by our users and our employees. The (fiscal) year 2005 was a very successful one for the APS. The number of users grew to a record of more than 3,200, up 16 % from the previous year. The number of peerreviewed papers published by our users broke the level of 1,000 for the first time. And in this tenth anniversary year since the first light at the APS, we had our largest user meeting ever, with more than 600 participants. The machine reached its highest-ever availability and reliability, at better than 98 % delivered beam, and a mean time between failures of more than 100

J. Murray; G Ibson

348

Statistical Mechanics  

Microsoft Academic Search

We review and further develop a mathematical framework for non-equilibrium quantum statistical mechanics recently proposed in (JP4, JP5, JP6, Ru3, Ru4, Ru5, Ru6). In the alge- braic formalism of quantum statistical mechanics we introduce notions of non-equilibrium steady states, entropy production and heat fluxes, and study their properties. Our basic paradigm is a model of a small (finite) quantum system

V. Jaksi ´; C.-A. Pillet

1937-01-01

349

Photon-Photon Interactions via Rydberg Blockade  

SciTech Connect

We develop the theory of light propagation under the conditions of electromagnetically induced transparency in systems involving strongly interacting Rydberg states. Taking into account the quantum nature and the spatial propagation of light, we analyze interactions involving few-photon pulses. We show that this system can be used for the generation of nonclassical states of light including trains of single photons with an avoided volume between them, for implementing photon-photon gates, as well as for studying many-body phenomena with strongly correlated photons.

Gorshkov, Alexey V. [Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Otterbach, Johannes [Department of Physics and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, 67663, Kaiserslautern (Germany); Fleischhauer, Michael [Department of Physics and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, 67663, Kaiserslautern (Germany); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Pohl, Thomas [Max Planck Institute for the Physics of Complex Systems, 01187 Dresden (Germany); Lukin, Mikhail D. [Physics Department, Harvard University, Cambridge, Massachusetts 02138 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)

2011-09-23

350

Number Track  

NSDL National Science Digital Library

Students can use this interactive Flash applet to practice ordering whole numbers within 20. The applet displays a track and number tiles, which the user drags to create the correct sequence of numbers 1 through 20. Users may choose from four levels: place 5 missing numbers, place 10 numbers, arrange all 20 numbers, or create your own challenge.

Dan Bunker

2010-01-01

351

Optomechanical photon shuttling between photonic cavities  

NASA Astrophysics Data System (ADS)

Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave mixing between photons and phonons, and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong non-local effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a multicavity optomechanical device in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of this ‘photon see-saw’, are modulated antisymmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation, which strongly modulates the inter-cavity coupling and shuttles photons to the other empty cavity during every oscillation cycle in a well-regulated fashion.

Li, Huan; Li, Mo

2014-11-01

352

Transitioning from micro to nano-photonics with Photonic Crystal Fibers Maksim Skorobogatiy  

E-print Network

Transitioning from micro to nano-photonics with Photonic Crystal Fibers Maksim Skorobogatiy that contain a large number of micro- and nano-sized voids or layers. It is the complexity of the fiber by the strongly subwavelength (/5-/10) features present in the fiber crossection. The "nano" size of such features

Skorobogatiy, Maksim

353

MULTISCALE DNA PARTITIONING: STATISTICAL EVIDENCE FOR SEGMENTS  

E-print Network

for various partitioning criteria such as GC content, local ancestry in population genetics, or copy number a new ap- proach that provides statistical error control: as in statistical hypothesis testing

Munk, Axel

354

SOCR: Statistics Online Computational Resource  

ERIC Educational Resources Information Center

The need for hands-on computer laboratory experience in undergraduate and graduate statistics education has been firmly established in the past decade. As a result a number of attempts have been undertaken to develop novel approaches for problem-driven statistical thinking, data analysis and result interpretation. In this paper we describe an…

Dinov, Ivo D.

2006-01-01

355

Large numbers hypothesis. II - Electromagnetic radiation  

NASA Astrophysics Data System (ADS)

This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

Adams, P. J.

1983-05-01

356

Large numbers hypothesis. II - Electromagnetic radiation  

NASA Technical Reports Server (NTRS)

This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

Adams, P. J.

1983-01-01

357

Modern Statistical Methods for GLAST Event Analysis  

E-print Network

We describe a statistical reconstruction methodology for the GLAST LAT. The methodology incorporates in detail the statistics of the interactions of photons and charged particles with the tungsten layers in the LAT, and uses the scattering distributions to compute the full probability distribution over the energy and direction of the incident photons. It uses model selection methods to estimate the probabilities of the possible geometrical configurations of the particles produced in the detector, and numerical marginalization over the energy loss and scattering angles at each layer. Preliminary results show that it can improve on the tracker-only energy estimates for muons and electrons incident on the LAT.

Robin D. Morris; Johann Cohen-Tanugi

2007-03-28

358

Number Sense  

NSDL National Science Digital Library

Hacker has given you a challenge. He’ll run his number machine to create a number. Then you’ll get three numbers between one and nine. The challenge is to make a number that is larger than the one on Hacker’s machine. Be careful though--Hacker will give you numbers that can’t be bigger than his!

2008-01-01

359

WHO: World Health Statistics  

NSDL National Science Digital Library

The World Health Organization (WHO) provides a vast array of materials on global public health statistics for policy makers, journalists, and other such folks. On the site, visitors can look over reports dating back to 2005 and they are welcome to download specific sections or the entire report if so desired. Reports are usually available in at least three languages (French, Spanish, and English) and they include coverage of the health-related Millennium Development Goals, global health indicators, and a number of appendices. Additionally, users can also look over specific country statistics and an elaborate map gallery.

2014-01-01

360

State-dependent photon blockade via quantum-reservoir engineering  

NASA Astrophysics Data System (ADS)

An arbitrary initial state of an optical or microwave field in a lossy driven nonlinear cavity can be changed into a partially incoherent superposition of only the vacuum and the single-photon states. This effect is known as single-photon blockade, which is usually analyzed for a Kerr-type nonlinear cavity parametrically driven by a single-photon process assuming single-photon loss mechanisms. We study photon blockade engineering via a nonlinear reservoir, i.e., a quantum reservoir, where only two-photon absorption is allowed. Namely, we analyze a lossy nonlinear cavity parametrically driven by a two-photon process and allowing two-photon loss mechanisms, as described by the master equation derived for a two-photon absorbing reservoir. The nonlinear cavity engineering can be realized by a linear cavity with a tunable two-level system via the Jaynes-Cummings interaction in the dispersive limit. We show that by tuning properly the frequencies of the driving field and the two-level system, the steady state of the cavity field can be the single-photon Fock state or a partially incoherent superposition of several Fock states with photon numbers, e.g., (0,2), (1,3), (0,1,2), or (0,2,4). At the right (now fixed) frequencies, we observe that an arbitrary initial coherent or incoherent superposition of Fock states with an even (odd) number of photons is changed into a partially incoherent superposition of a few Fock states of the same photon-number parity. We find analytically approximate formulas for these two kinds of solutions for several differently tuned systems. A general solution for an arbitrary initial state is a weighted mixture of the above two solutions with even and odd photon numbers, where the weights are given by the probabilities of measuring the even and odd numbers of photons of the initial cavity field, respectively. This can be interpreted as two separate evolution-dissipation channels for even and odd-number states. Thus, in contrast to the standard predictions of photon blockade, we prove that the steady state of the cavity field, in the engineered photon blockade, can depend on its initial state. To make our results more explicit, we analyze photon blockades for some initial infinite-dimensional quantum and classical states via the Wigner and photon-number distributions.

Miranowicz, Adam; Bajer, Ji?í; Paprzycka, Ma?gorzata; Liu, Yu-xi; Zagoskin, Alexandre M.; Nori, Franco

2014-09-01

361

Three-Dimensional Statistics of Radio Polarimetry  

E-print Network

The measurement of radio polarization may be regarded as a three-dimensional statistical problem because the large photon densities at radio wavelengths allow the simultaneous detection of the three Stokes parameters which completely describe the radiation's polarization. The statistical nature of the problem arises from the fluctuating instrumental noise, and possibly from fluctuations in the radiation's polarization. A statistical model is used to derive the general, three-dimensional statistics that govern radio polarization measurements. The statistics are derived for specific cases of source-intrinsic polarization, with an emphasis on the orthogonal polarization modes in pulsar radio emission. The statistics are similar to those commonly found in other fields of the physical, biological, and Earth sciences. Given the highly variable linear and circular polarization of pulsar radio emission, an understanding of the three-dimensional statistics may be an essential prequisite to a thorough interpretation of pulsar polarization data.

Mark M. McKinnon

2003-06-03

362

Number Line  

NSDL National Science Digital Library

This iOS app helps students to visualize number sentences and create models for addition, subtractions, multiplication, and division. The number line can be adjusted to represent multiples of numbers from one to one hundred.

Clarity Innovations, Inc.

2013-11-22

363

Effective Atomic Numbers of Heterogeneous Materials  

Microsoft Academic Search

FOR a single element, the three gamma-ray processes-photoelectric, Compton and pair production, can be expressed as a function of photon energy hnu and the atomic number Z of the element. At a given photon energy, the interaction is proportional to Zn where n is between 4 and 5 for the photoelectric effect, 1 for the Compton effect, and 2 for

R. C. Murty

1965-01-01

364

Mystery Number  

NSDL National Science Digital Library

This game for 2-3 players (K-5) combines logic and numbers. Players start with a 10x10 grid of the numbers 1 to 100. One person chooses a secret number and announces the range in which it falls. Other players ask yes or no questions to identify the number. They cross out the numbers on the board that are no longer possibilities. The player who identifies the secret number wins. Available as a downloadable pdf in English or in Spanish.

2011-01-01

365

Statistical Engineering  

NSDL National Science Digital Library

A good resource for problems in statistics in engineering. Contains some applets, and good textual examples related to engineering. Some topics include Monte Carlo method, Central Limit Theorem, Risk, Logistic Regression, Generalized Linear Models, and Confidence. Overall, this is a well presented and good site for anyone interested in engineering or mathematics.

Annis, Charles

366

Statistics Investigations  

NSDL National Science Digital Library

This webpage contains statistics investigations in the form of word problems. The investigations are located on the left hand side of the page on the navigation bar: the links are "Recommended Investigations" and "Additional Investigations". Within each investigation there are additional links to external resources that can be used to solve or illustrate the problem.

2013-01-01

367

Pion and kaon pair production in photon-photon collisions  

Microsoft Academic Search

We report measurements of the two-photon processes e+e--->e+e-pi+pi- and e+e--->e+e-K+K-, at an e+e- center-of-mass energy of 29 GeV. In the pi+pi- data a high-statistics analysis of the f(1270) results in a gammagamma width Gamma(gammagamma-->f)=3.2+\\/-0.4 keV. The pi+pi- continuum below the f mass is well described by a QED Born approximation, whereas above the f mass it is consistent with a

H. Aihara; M. Alston-Garnjost; R. E. Avery; A. Barbaro-Galtieri; A. R. Barker; A. V. Barnes; B. A. Barnett; D. A. Bauer; H.-U. Bengtsson; D. L. Bintinger; B. J. Blumenfeld; G. J. Bobbink; A. D. Bross; C. D. Buchanan; A. Buijs; M. P. Cain; D. O. Caldwell; O. Chamberlain; C.-Y. Chien; A. R. Clark; G. D. Cowan; D. A. Crane; O. I. Dahl; K. A. Derby; J. J. Eastman; P. H. Eberhard; A. M. Eisner; R. Enomoto; F. C. Erne-acute-accent; T. Fujii; B. Gabioud; J. W. Gary; W. Gorn; J. M. Hauptman; W. Hofmann; J. E. Huth; J. Hylen; U. P. Joshi; T. Kamae; H. S. Kaye; K. H. Kees; R. W. Kenney; L. T. Kerth; Winston Ko; R. I. Koda; R. R. Kofler; K. K. Kwong; R. L. Lander; W. G. J. Langeveld; J. G. Layter; F. L. Linde; C. S. Lindsey; S. C. Loken; A. Lu; X.-Q. Lu; G. R. Lynch; R. J. Madaras; K. Maeshima; B. D. Magnuson; J. N. Marx; K. Maruyama; G. E. Masek; L. G. Mathis; J. A. J. Matthews; S. J. Maxfield; S. O. Melnikoff; E. S. Miller; W. Moses; R. R. McNeil; P. Nemethy; D. R. Nygren; P. J. Oddone; H. P. Paar; D. A. Park; D. E. Pellett; M. Pripstein; M. T. Ronan; R. R. Ross; F. R. Rouse; R. R. Sauerwein; K. A. Schwitkis; J. C. Sens; G. Shapiro; M. D. Shapiro; B. C. Shen; W. E. Slater; J. R. Smith; J. S. Steinman; M. L. Stevenson; D. H. Stork; M. G. Strauss; M. K. Sullivan; T. Takahashi; J. R. Thompson; N. Toge; R. van Tyen; B. van Uitert; G. J. Vandalen; R. F. van Daalen Wetters; W. Vernon; W. Wagner; E. M. Wang; Y. X. Wang; M. R. Wayne; W. A. Wenzel; J. T. White; M. C. Williams; Z. R. Wolf; H. Yamamoto; M. Yamauchi; S. J. Yellin; C. Zeitlin; W.-M. Zhang

1986-01-01

368

Nuclear photonics  

NASA Astrophysics Data System (ADS)

With the planned new ?-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 1013 ?/s and a band width of ?E?/E??10-3, a new era of ? beams with energies up to 20MeV comes into operation, compared to the present world-leading HI?S facility at Duke University (USA) with 108 ?/s and ?E?/E??3?10-2. In the long run even a seeded quantum FEL for ? beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused ? beams. Here we describe a new experiment at the ? beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for ? beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for ? beams are being developed. Thus, we have to optimize the total system: the ?-beam facility, the ?-beam optics and ? detectors. We can trade ? intensity for band width, going down to ?E?/E??10-6 and address individual nuclear levels. The term "nuclear photonics" stresses the importance of nuclear applications. We can address with ?-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, ? beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to ?m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

Habs, D.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.

2012-07-01

369

Nuclear photonics  

SciTech Connect

With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here we describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

Habs, D.; Guenther, M. M.; Jentschel, M.; Thirolf, P. G. [Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Max Planck Institut fuer Quantenoptik, D-85748 Garching (Germany); Institut Laue-Langevin, F-38042 Grenoble (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

2012-07-09

370

A study of photon interaction parameters in lung tissue substitutes  

PubMed Central

The study of photon interaction with different composite materials has become a topic of prime importance for radiation physicists. Some parameters of dosimetric interest are the mass attenuation coefficient, effective atomic number, and electron density; these help in the basic understanding of photon interactions with composite materials. The photon interaction parameters such as mass attenuation coefficient (?/?), effective atomic number (Zeff), and effective electron density (Nel) must be identical for the phantom material and their tissue. In the present study, we have evaluated the photon interaction parameters such as (?/?), Zeff and Nel of 13 lung tissue substitutes. The variations of these parameters of lung tissue substitutes with photon energy are graphically represented. The photon interaction parameters of lung tissue substitutes are compared with that of lung tissue. The variation of photon interaction parameters of the studied lung tissue substitutes is similar that of the lung. Logically, it can be shown that Alderson lung is good substitute for lung than the other substitutes. PMID:24872609

Manjunatha, H. C.

2014-01-01

371

Teleporting photonic qudits using multimode quantum scissors.  

PubMed

Teleportation plays an important role in the communication of quantum information between the nodes of a quantum network and is viewed as an essential ingredient for long-distance Quantum Cryptography. We describe a method to teleport the quantum information carried by a photon in a superposition of a number d of light modes (a "qudit") by the help of d additional photons based on transcription. A qudit encoded into a single excitation of d light modes (in our case Laguerre-Gauss modes which carry orbital angular momentum) is transcribed to d single-rail photonic qubits, which are spatially separated. Each single-rail qubit consists of a superposition of vacuum and a single photon in each one of the modes. After successful teleportation of each of the d single-rail qubits by means of "quantum scissors" they are converted back into a qudit carried by a single photon which completes the teleportation scheme. PMID:24352610

Goyal, Sandeep K; Konrad, Thomas

2013-01-01

372

Digest of Education Statistics 2000  

NSDL National Science Digital Library

In late January, the National Center for Education Statistics (NCES) released this new publication. Published January 26th 2001, the Digest of Education Statistics, 2000 "provides a compilation of statistical information covering the broad field of education from prekindergarten through graduate school." Data in the digest cover "the number of schools and colleges; teachers; enrollments; graduates; educational attainment; finances; federal funds for education; employment and income of graduates; libraries; technology; and international comparisons." (The Digest of Education Statistics, 1999 was featured in the April 4th, 2000 Scout Report for the Social Sciences.) The publication is in .pdf format and may be downloaded in its entirety or in selected chapters.

2001-01-01

373

Digest of Education Statistics 2001  

NSDL National Science Digital Library

On March 1, 2002, the National Center for Education Statistics released Digest of Education Statistics, 2001. This report provides "a compilation of statistical information covering the broad field of education from prekindergarten through graduate school." Topics covered by the Digest include information on the number of US schools and colleges, teachers, enrollments, and graduates, as well as information on educational attainment, finances, Federal funds for education, employment and income of graduates, libraries, technology, and international comparisons. The report consists of seven chapters, an appendix, an index, and definitions -- downloadable, viewable, and printable in its entirety or by chapter. (The Digest of Education Statistics, 2000 was featured in the February 6, 2001 Scout Report).

2002-01-01

374

Photon channelling in foams  

NASA Astrophysics Data System (ADS)

We report on the absorption of diffuse photons in aqueous foams by a dye added to the continuous liquid phase. For very wet and for dry foams, the absorption of the diffuse photons equals the absorption length of the liquid divided by the liquid volume fraction. This indicates that the diffuse photons propagate by a random walk, sampling each phase in proportion to its volume. Foams of intermediate wetness, by contrast, absorb photons more strongly than expected. A 2D computer simulation, modeling photons scattering in a foam crystal, also shows enhanced absorption. This encourages us to consider novel transport effects, such as the total internal reflection of photons inside the Plateau borders.

Gittings, A. S.; Bandyopadhyay, R.; Durian, D. J.

2004-02-01

375

Four Faculty Positions Applied Statistics & Computational Statistics  

E-print Network

Four Faculty Positions Applied Statistics & Computational Statistics The Department of Statistics at the Assistant Professor rank. Two positions are open in the area of Applied Statistics, with a focus on the development of statistical methodology and statistical consulting. The other two positions are open

Shepp, Larry

376

Number Explorer  

NSDL National Science Digital Library

This interactive application helps students to learn visually about numbers from their possible arrangements and how those arrangements relate to division, multiplication, and factors. The web applet divides numbers and displays calculation to show the remainder as a number, fraction, or decimal value and allows demonstration of types of numbers such as prime, square, and triangular. The number explorer has automated tests for divisibility, factor pairs, or prime factors. Three different shapes can be used, the original fish swim around and obediently arrange themselves to show number properties. However balls or cards cards can be used instead, these animate faster and are better for displaying numbers.

2012-01-01

377

Number Sense  

NSDL National Science Digital Library

In this online math game from Cyberchase, learners play against Hacker in a place value game. The goal is to make a number bigger than the one created by Hacker's number machine. Learners select the numbers in the order in which they want them to go into their machine. The challenge is to either make a number larger than the one on Hacker's machine or realize that it's impossible to make a number bigger than Hacker's, no matter what the combination.

2013-12-04

378

Number Tracks  

NSDL National Science Digital Library

This problem provides an opportunity for children to explore and visualize number patterns and sequences and to reinforce key number concepts and vocabulary such as odd and even, factors and multiples. Students cut consecutive number tracks into equal length pieces in several ways and investigate the patterns that emerge among the sums of the tracks. The Teachers' Notes page explains number tracks and offers suggestions for implementation, discussion questions, a printable sheet of number tracks (pdf), and ideas for extension and support.

379

Number Flash  

NSDL National Science Digital Library

This iOS app helps students make the transition from counting to number recognition by thinking of a number of objects in relation to five and ten. The app displays a set number of items from one to twenty in ten frames then flashes away after the preset number of seconds. The user must identify the number that was shown on the ten frames.

Mark, Mitchell

2013-03-10

380

Learning Statistics By Doing Statistics  

NSDL National Science Digital Library

This article, created by Gary Smith of Pomona College, discusses a project-based approach to teaching statistics. The article focuses on the team aspect of learning, it introduces concepts such as: working with data, learning by doing, learning by writing, learning by speaking, and authentic assessment of material. An appendix contains a list of twenty projects that have been successfully assigned.

Smith, Gary

381

Topological Invariants in Point Group Symmetric Photonic Topological Insulators  

E-print Network

We proposed a group-theory method to calculate topological invariant in bi-isotropic photonic crystals invariant under crystallographic point group symmetries. Spin Chern number has been evaluated by the eigenvalues of rotation operators at high symmetry k-points after the pseudo-spin polarized fields are retrieved. Topological characters of photonic edge states and photonic band gaps can be well predicted by total spin Chern number. Nontrivial phase transition is found in large magnetoelectric coupling due to the jump of total spin Chern number. Light transport is also issued at the {\\epsilon}/{\\mu} mismatching boundary between air and the bi-isotropic photonic crystal. This finding presents the relationship between group symmetry and photonic topological systems, which enables the design of photonic nontrivial states in a rational manner.

Chen, Xiao-Dong; Chen, Wen-Jie; Wang, Jia-Rong; Dong, Jian-Wen

2014-01-01

382

Occupational Employment Statistics  

NSDL National Science Digital Library

US occupations are featured in this information-rich resources from the Bureau of Labor Statistics. The 1996 Occupational Employment Statistics Survey differs from previous surveys in that it includes wage data by occupation for the first time. The site contains a description of the survey and complete national and state data for 760 occupations in seven major areas. Included are occupation title, number of employees, hourly mean and median wage, and an OES code number that provides information about the occupation and its employment distribution by wage range where surveyed (distribution is for the national survey only). An occupational search engine is forthcoming. The site also contains information about previous OES surveys back to 1988.

383

Two-photon pattern in a second-order interference  

NASA Astrophysics Data System (ADS)

An interferometric arrangement utilizing a pair of twin photons, generated by parametric down-conversion, is devised to show second-order interferences revealing de Broglie's wavelength of the photon pair as a whole and the Pancharatnam phase depending on the number of photons. This proposed experiment utilizes the phenomenon ``induced coherence without stimulated emission'' to generate a coherent superposition of states distinct from the usual superposition with beam splitters, where the photons are independently scattered. In this experiment interference occurs due to recombination of photon trajectories on a beam splitter and also through frustration or enhancement of the down-conversion processes.

Arnaut, H. H.; Barbosa, G. A.

1998-11-01

384

Statistical Shorts  

NSDL National Science Digital Library

In this statistics and probability activity students must determine whether each statement is always true, sometimes true, sometimes false, or always false. Students must have a basic understanding of probability statements and the foundation for understanding mean, median, and mode in order to complete this activity for all twelve statements. In addition to the task, tips for getting started, possible solutions, a teacher resource page, and a printable page are provided.

NRICH

2013-01-01

385

Statistical Optics  

NASA Astrophysics Data System (ADS)

The Wiley Classics Library consists of selected books that have become recognized classics in their respective fields. With these new unabridged and inexpensive editions, Wiley hopes to extend the life of these important works by making them available to future generations of mathematicians and scientists. Currently available in the Series: T. W. Anderson The Statistical Analysis of Time Series T. S. Arthanari & Yadolah Dodge Mathematical Programming in Statistics Emil Artin Geometric Algebra Norman T. J. Bailey The Elements of Stochastic Processes with Applications to the Natural Sciences Robert G. Bartle The Elements of Integration and Lebesgue Measure George E. P. Box & Norman R. Draper Evolutionary Operation: A Statistical Method for Process Improvement George E. P. Box & George C. Tiao Bayesian Inference in Statistical Analysis R. W. Carter Finite Groups of Lie Type: Conjugacy Classes and Complex Characters R. W. Carter Simple Groups of Lie Type William G. Cochran & Gertrude M. Cox Experimental Designs, Second Edition Richard Courant Differential and Integral Calculus, Volume I RIchard Courant Differential and Integral Calculus, Volume II Richard Courant & D. Hilbert Methods of Mathematical Physics, Volume I Richard Courant & D. Hilbert Methods of Mathematical Physics, Volume II D. R. Cox Planning of Experiments Harold S. M. Coxeter Introduction to Geometry, Second Edition Charles W. Curtis & Irving Reiner Representation Theory of Finite Groups and Associative Algebras Charles W. Curtis & Irving Reiner Methods of Representation Theory with Applications to Finite Groups and Orders, Volume I Charles W. Curtis & Irving Reiner Methods of Representation Theory with Applications to Finite Groups and Orders, Volume II Cuthbert Daniel Fitting Equations to Data: Computer Analysis of Multifactor Data, Second Edition Bruno de Finetti Theory of Probability, Volume I Bruno de Finetti Theory of Probability, Volume 2 W. Edwards Deming Sample Design in Business Research

Goodman, Joseph W.

2000-07-01

386

Statistics I  

NSDL National Science Digital Library

Students will encounter the concept of a distribution, along with parameters that describe a distribution's "typical" values (average) and a distribution's spread (variance). To understand simple distributions and uncertainty propagation in the coming sections, it is necessary to be familiar with the concept of statistical independence. When two variables fluctuate independently, their covariance vanishes, and the variance of their sum is the sum of their variances.

2013-06-21

387

A Diamond Nanowire Single Photon Antenna  

E-print Network

The development of a robust light source that emits one photon at a time is an outstanding challenge in quantum science and technology. Here, at the transition from many to single photon optical communication systems, fully quantum mechanical effects may be utilized to achieve new capabilities, most notably perfectly secure communication via quantum cryptography. Practical implementations place stringent requirements on the device properties, including stable photon generation, room temperature operation, and efficient extraction of many photons. Single photon light emitting devices based on fluorescent dye molecules, quantum dots, and carbon nanotube material systems have all been explored, but none have simultaneously demonstrated all criteria. Here, we describe the design, fabrication, and characterization of a bright source of single photons consisting of an individual Nitrogen-vacancy color center (NV center) in a diamond nanowire operating in ambient conditions. The nanowire plays a positive role in increasing the number of single photons collected from the NV center by an order of magnitude over devices based on bulk diamond crystals, and allows operation at an order of magnitude lower power levels. This result enables a new class of nanostructured diamond devices for room temperature photonic and quantum information processing applications, and will also impact fields as diverse as biological and chemical sensing, opto-mechanics, and scanning-probe microscopy.

Tom Babinec; Birgit J. M. Hausmann; Mughees Khan; Yinan Zhang; Jero Maze; Philip R. Hemmer; Marko Loncar

2009-10-28

388

Photonics: how to get familiar with it  

NASA Astrophysics Data System (ADS)

Year 2010 brought the 50th anniversary of laser. Our century seems to be called the photon-century. Light in our lives plays both pervasive and primordial role. To describe the new role of today "interdisciplinary optics" a new term - photonics appeared. The term was coined in 1967 by Pierre Aigrain, a French scientist, who defined photonics as the science of the harnessing of light. Photonics encompasses the generation of light, the detection of light, the management of light through guidance, manipulation, and amplification, and most importantly, its utilisation for the benefit of mankind. Number of photonics applications proves its importance. On one side, there is a demand for skilled people with photonics training. On the other side, nearly everyone is affected by science in a way and it would be useful to have at least a basic understanding of scientific principles. However, it is not a brand-new idea, an effort to popularise new scientific achievements has still been present. The contribution is based on experience of popularising photonics to high school students and attracting undergraduate University students for basis of optics via photonics. The aim of it is to share and exchange experience.

Senderáková, Dagmar; Mesaros, Vladimir; Strba, Anton

2010-12-01

389

Heavy flavor production from photons and hadrons  

SciTech Connect

The present state of the production and observation of hadrons containing heavy quarks or antiquarks as valence constituents, in reactions initiated by real and (space-like) virtual photon or by hadron beams is discussed. Heavy flavor production in e/sup +/e/sup -/ annihilation, which is well covered in a number of recent review papers is not discussed, and similarly, neutrino production is omitted due to the different (flavor-changing) mechanisms that are involved in those reactions. Heavy flavors from spacelike photons, heavy flavors from real photons, and heavy flavors from hadron-hadron collisions are discussed. (WHK)

Heusch, C.A.

1982-01-01

390

Topology optimization in nano-photonics  

NASA Astrophysics Data System (ADS)

The topology optimization method is a finite element based design method that optimizes material distributions subject to various objective functions and constraints. The method was originally developed for mechanical engineering problem and is by now widely used in automotive and aerospace applications. The method has within the last 5 years been applied to a number of design problems within nano-photonics. Examples are photonic crystals and photonic crystal based waveguides and filters. The presentation will give an overview of previous works and discuss recent applications within meta-material and cloaking design.

Sigmund, O.

2009-10-01

391

Juvenile Court Statistics 1967. Children's Bureau Statistical Series 93.  

ERIC Educational Resources Information Center

A summary of delinquency, traffic, and other cases, sources and limitations of data, and the definition of six terms precedes 14 tables of statistics. Tables cover the following cases disposed of in 1967: number of delinquency cases; manner of handling cases; rate of delinquency cases; percent change in delinquency cases; number and manner of…

Children's Bureau (DHEW), Washington, DC.

392

Dow Corning photonics: the silicon advantage in automotive photonics  

NASA Astrophysics Data System (ADS)

The Automotive Market offers several opportunities for Dow Corning to leverage the power of silicon-based materials. Dow Corning Photonics Solutions has a number of developments that may be attractive for the emergent photonics needs in automobiles, building on 40 years of experience as a leading Automotive supplier with a strong foundation of expertise and an extensive product offering- from encapsulents and highly reliable resins, adhesives, insulating materials and other products, ensuring that the advantage of silicones are already well-embedded in Automotive systems, modules and components. The recent development of LED encapsulants of exceptional clarity and stability has extended the potential for Dow Corning"s strength in Photonics to be deployed "in-car". Demonstration of board-level and back-plane solutions utilising siloxane waveguide technology offers new opportunities for systems designers to integrate optical components at low cost on diverse substrates. Coupled with work on simple waveguide technology for sensors and data communications applications this suite of materials and technology offerings is very potent in this sector. The harsh environment under hood and the very extreme thermal range that materials must sustain in vehicles due to both their engine and the climate is an applications specification that defines the siloxane advantage. For these passive optics applications the siloxanes very high clarity at the data-communications wavelengths coupled with extraordinary stability offers significant design advantage. The future development of Head-Up-Displays for instrumentation and data display will offer yet more opportunities to the siloxanes in Automotive Photonics.

Clapp, Terry V.; Paquet, Rene; Norris, Ann; Pettersen, Babette

2005-02-01

393

Bayesian reconstruction of photon interaction sequences for high-resolution PET detectors  

PubMed Central

Realizing the full potential of high-resolution positron emission tomography (PET) systems involves accurately positioning events in which the annihilation photon deposits all its energy across multiple detector elements. Reconstructing the complete sequence of interactions of each photon provides a reliable way to select the earliest interaction because it ensures that all the interactions are consistent with one another. Bayesian estimation forms a natural framework to maximize the consistency of the sequence with the measurements while taking into account the physics of ?-ray transport. An inherently statistical method, it accounts for the uncertainty in the measured energy and position of each interaction. An algorithm based on maximum a posteriori (MAP) was evaluated for computer simulations. For a high-resolution PET system based on cadmium zinc telluride detectors, 93.8% of the recorded coincidences involved at least one photon multiple-interactions event (PMIE). The MAP estimate of the first interaction was accurate for 85.2% of the single photons. This represents a two-fold reduction in the number of mispositioned events compared to minimum pair distance, a simpler yet efficient positioning method. The point-spread function of the system presented lower tails and higher peak value when MAP was used. This translated into improved image quality, which we quantified by studying contrast and spatial resolution gains. PMID:19652293

Pratx, Guillem

2013-01-01

394

Generation of a highly phase sensitive polarization squeezed N-photon state by collinear parametric downconversion and coherent photon subtraction  

E-print Network

It is shown that a highly phase sensitive polarization squeezed (2n-1)-photon state can be generated by subtracting a diagonally polarized photon from the 2n photon component generated in collinear type II downconversion. This polarization wedge state has the interesting property that its photon number distribution in the horizontal and vertical polarizations remains sharply defined for phase shifts of up to 1/n between the circularly polarized components. Phase shifts at the Heisenberg limit are therefore observed as nearly deterministic transfers of a single photon between the horizontal and vertical polarization components.

Holger F. Hofmann

2006-05-23

395

VOLUME 88, NUMBER 6 P H Y S I C A L R E V I E W L E T T E R S 11 FEBRUARY 2002 Waiting-Time Statistics of Self-Organized-Criticality Systems  

E-print Network

-Time Statistics of Self-Organized-Criticality Systems R. Sánchez,1,* D. E. Newman,2 and B. A. Carreras3 1- acteristics strikingly similar to those found in systems following the self-organized-criticality (SOC the threshold is locally overcome and the system then self- organizes itself via fast relaxation events

Newman, David

396

Ultrabright source of entangled photon pairs.  

PubMed

A source of triggered entangled photon pairs is a key component in quantum information science; it is needed to implement functions such as linear quantum computation, entanglement swapping and quantum teleportation. Generation of polarization entangled photon pairs can be obtained through parametric conversion in nonlinear optical media or by making use of the radiative decay of two electron-hole pairs trapped in a semiconductor quantum dot. Today, these sources operate at a very low rate, below 0.01 photon pairs per excitation pulse, which strongly limits their applications. For systems based on parametric conversion, this low rate is intrinsically due to the Poissonian statistics of the source. Conversely, a quantum dot can emit a single pair of entangled photons with a probability near unity but suffers from a naturally very low extraction efficiency. Here we show that this drawback can be overcome by coupling an optical cavity in the form of a 'photonic molecule' to a single quantum dot. Two coupled identical pillars-the photonic molecule-were etched in a semiconductor planar microcavity, using an optical lithography method that ensures a deterministic coupling to the biexciton and exciton energy states of a pre-selected quantum dot. The Purcell effect ensures that most entangled photon pairs are emitted into two cavity modes, while improving the indistinguishability of the two optical recombination paths. A polarization entangled photon pair rate of 0.12 per excitation pulse (with a concurrence of 0.34) is collected in the first lens. Our results open the way towards the fabrication of solid state triggered sources of entangled photon pairs, with an overall (creation and collection) efficiency of 80%. PMID:20613838

Dousse, Adrien; Suffczy?ski, Jan; Beveratos, Alexios; Krebs, Olivier; Lemaître, Aristide; Sagnes, Isabelle; Bloch, Jacqueline; Voisin, Paul; Senellart, Pascale

2010-07-01

397

Scalable Spatial Superresolution Using Entangled Photons  

NASA Astrophysics Data System (ADS)

N00N states—maximally path-entangled states of N photons—exhibit spatial interference patterns sharper than any classical interference pattern. This is known as superresolution. However, even given perfectly efficient number-resolving detectors, the detection efficiency of all previous measurements of such interference would decrease exponentially with the number of photons in the N00N state, often leading to the conclusion that N00N states are unsuitable for spatial measurements. A technique known as the "optical centroid measurement" has been proposed to solve this and has been experimentally verified for photon pairs; here we present the first extension beyond two photons, measuring the superresolution fringes of two-, three-, and four-photon N00N states. Moreover, we compare the N00N-state interference to the corresponding classical superresolution interference. Although both provide the same increase in spatial frequency, the visibility of the classical fringes decreases exponentially with the number of detected photons. Our work represents an essential step forward for quantum-enhanced measurements, overcoming what was believed to be a fundamental challenge to quantum metrology.

Rozema, Lee A.; Bateman, James D.; Mahler, Dylan H.; Okamoto, Ryo; Feizpour, Amir; Hayat, Alex; Steinberg, Aephraim M.

2014-06-01

398

Photonic crystal fibers  

Microsoft Academic Search

Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications of photonic crystal fibers with particular emphasis on recent advances in the field.

J. Laegsgaard; K. P. Hansen; M. D. Nielsen; T. P. Hansen; J. Riishede; K. Hougaard; T. Sorensen; T. T. Larsen; N. A. Mortensent; J. Broeng; J. B. Jensen; A. Bjarklev

2003-01-01

399

Photon Physics in ALICE  

E-print Network

We give an overview of photon physics which will be studied by the ALICE experiment in proton-proton and heavy ion collisions at LHC. We compare properties of ALICE photon detectors and estimate their ability to measure neutral meson and direct photon spectra as well as gamma-hadron and gamma-jet correlations in pp and Pb+Pb collisions.

D. Peressounko; Y. Kharlov; for the ALICE collaboration

2009-09-17

400

Problems on Non-Equilibrium Statistical Physics  

E-print Network

Four problems in non-equilibrium statistical physics are investigated: 1. The thermodynamics of single-photon gas; 2. Energy of the ground state in Multi-electron atoms; 3. Energy state of the H2 molecule; and 4. The Condensation behavior in N...

Kim, Moochan

2011-08-08

401

Remarks on statistical errors in equivalent widths  

E-print Network

Equivalent width measurements for rapid line variability in atomic spectral lines are degraded by increasing error bars with shorter exposure times. We derive an expression for the error of the line equivalent width $\\sigma(W_\\lambda)$ with respect to pure photon noise statistics and provide a correction value for previous calculations.

Klaus Vollmann; Thomas Eversberg

2006-07-03

402

Number Cruncher  

NSDL National Science Digital Library

This Science NetLinks interactive game helps students increase their logic and decision making skills by challenging a player to consider a series of mathematical processes to find a path from a starting number to a goal number in a math maze. The activity appears as a 5x5 matrix of numbers, each of which has an operation symbol next to it, indicating whether it will be added to, subtracted from, or multiplied by the previous number. Starting in the center with a given number, players choose an adjoining number to complete the next step and they proceed until successfully reaching the goal number or until they have run out of usable numbers on the game board. To add an additional challenge to the game, a player can limit each level to reaching the target in seven or fewer steps.

2011-10-13

403

Complex Numbers  

NSDL National Science Digital Library

This is a short study guide from the University of Maryland's Physics Education Research Group on introducing, interpreting, and using complex numbers. Mathematical equations are included to help students understand the nature of complex numbers.

2010-04-01

404

Number Theory  

Microsoft Academic Search

Comments on the article by Gardner Murphy , which considered the psychological sources of Pythagorean number theory. The current author offers some supplementary information, noting that there are some additional meanings attached to some numbers in the culture of India.

Santokh S. Anant

1968-01-01

405

Tooth Numbering  

MedlinePLUS

... numbered as well. Illustrations created by Simple Steps designer Michael Becker Universal Numbering System Adults In this ... indicates that it is a deciduous (primary or "baby") tooth. So, a child's first tooth on the ...

406

Single-Photon Transistor Mediated by Interstate Rydberg Interactions  

NASA Astrophysics Data System (ADS)

We report on the realization of an all-optical transistor by mapping gate and source photons into strongly interacting Rydberg excitations with different principal quantum numbers in an ultracold atomic ensemble. We obtain a record switch contrast of 40% for a coherent gate input with mean photon number one and demonstrate attenuation of source transmission by over ten photons with a single gate photon. We use our optical transistor to demonstrate the nondestructive detection of a single Rydberg atom with a fidelity of 0.72(4).

Gorniaczyk, H.; Tresp, C.; Schmidt, J.; Fedder, H.; Hofferberth, S.

2014-08-01

407

Bose-Einstein condensation of photons in a 'white-wall' photon box  

NASA Astrophysics Data System (ADS)

Bose-Einstein condensation, the macroscopic ground state occupation of a system of bosonic particles below a critical temperature, has been observed in cold atomic gases and solid-state physics quasiparticles. In contrast, photons do not show this phase transition usually, because in Planck's blackbody radiation the particle number is not conserved and at low temperature the photons disappear in the walls of the system. Here we report on the realization of a photon Bose-Einstein condensate in a dye-filled optical microcavity, which acts as a "white-wall" photon box. The cavity mirrors provide a trapping potential and a non-vanishing effective photon mass, making the system formally equivalent to a two-dimensional gas of trapped massive bosons. Thermalization of the photon gas is reached in a number conserving way by multiple scattering off the dye molecules. Signatures for a BEC upon increased photon density are: a spectral distribution that shows Bose-Einstein distributed photon energies with a macroscopically populated peak on top of a broad thermal wing, the observed threshold of the phase transition showing the predicted absolute value and scaling with resonator geometry, and condensation appearing at the trap centre even for a spatially displaced pump spot.

Klärs, Jan; Schmitt, Julian; Vewinger, Frank; Weitz, Martin

2011-01-01

408

Negative Numbers  

NSDL National Science Digital Library

This article is an account of how negative numbers became part of the "vocabulary" of mathematicians and of some of the earliest appearances of negative numbers in calculations of the ancient civilizations of China, India and Greece. Although negative numbers were used in calculations, negative answers to mathematical problems were considered meaningless or impossible. The troubled history of negative numbers presented in this article shows how the simple mathematical principles taken for granted today have taken thousands of years to develop.

Howard, Jill

2009-05-01

409

Time-resolved measurement of photon states using two-photon interference with photons from short-time reference pulses  

E-print Network

To fully utilize the energy-time degree of freedom of photons for optical quantum information processes, it is necessary to control and characterize the quantum states of the photons at extremely short time scales. For measurements beyond the time resolution of available detectors, two-photon interference with a photon in a short time reference pulse may be a viable alternative. In this paper, we derive the temporal measurement operators for the bunching statistics of a single photon input state with a reference photon. It is shown that the effects of the pulse shape of the reference pulse can be expressed in terms of a spectral filter selecting the bandwidth within which the measurement can be treated as an ideal projection on eigenstates of time. For full quantum tomography, temporal coherence can be determined by using superpositions of reference pulses at two different times. Moreover, energy-time entanglement can be evaluated based on the two-by-two entanglement observed in the coherences between pairs of detection times.

Changliang Ren; Holger F. Hofmann

2011-06-01

410

Efficiency vs. multi-photon contribution test for quantum dots  

E-print Network

The development of linear quantum computing within integrated circuits demands high quality semiconductor single photon sources. In particular, for a reliable single photon source it is not sufficient to have a low multi-photon component, but also to possess high efficiency. We investigate the photon statistics of the emission from a single quantum dot with a method that is able to sensitively detect the trade-off between the efficiency and the multi-photon contribution. Our measurements show, that the light emitted from the quantum dot when it is resonantly excited possess a very low multi-photon content. Additionally, we demonstrated, for the first time, the non-Gaussian nature of the quantum state emitted from a single quantum dot.

Ana Predojevic; Miroslav Jezek; Tobias Huber; Harishankar Jayakumar; Thomas Kauten; Glenn S. Solomon; Radim Filip; Gregor Weihs

2014-03-19

411

Number Factory  

NSDL National Science Digital Library

This interactive Java applet promotes number sense, estimation, and provides practice with order of operations. The player's goal is to make a numerical expression using the four given numbers and the four basic operations with the result being the target number (or as close as they can get to it). The student can also use brackets in their calculation.

Doorman, Michiel

2012-01-07

412

Spike statistics  

E-print Network

In this paper we explore stochastical and statistical properties of so-called recurring spike induced Kasner sequences. Such sequences arise in recurring spike formation, which is needed together with the more familiar BKL scenario to yield a complete description of generic spacelike singularities. In particular we derive a probability distribution for recurring spike induced Kasner sequences, complementing similar available BKL results, which makes comparisons possible. As examples of applications, we derive results for so-called large and small curvature phases and the Hubble-normalized Weyl scalar.

J. Mark Heinzle; Claes Uggla

2012-12-21

413

Multiple photon emission in heavy particle decays  

NASA Technical Reports Server (NTRS)

Cosmic ray interactions, at energies above 1 TeV/nucleon, in emulsion chambers flown on high altitude balloons have yielded two events showing apparent decays of a heavy particle into one charged particle and four photons. The photons converted into electron pairs very close to the decay vertex. Attempts to explain this decay topology with known particle decays are presented. Unless both events represent a b yields u transition, which is statistically unlikely, then other known decay modes for charmed or bottom particles do not account satisfactorily for these observations. This could indicate, possibly, a new decay channel.

Asakimori, K.; Burnett, T. H.; Cherry, M. L.; Christl, M. J.; Dake, S.; Derrickson, J. H.; Fountain, W. F.; Fuki, M.; Gregory, J. C.; Hayashi, T.

1994-01-01

414

Optomechanical photon shuttling between photonic cavities  

E-print Network

Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave-mixing between photons and phonons and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong nonlocal effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a novel multi-cavity optomechanical device: a "photon see-saw", in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of the see-saw, are modulated anti-symmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation which strongly modulates the inter-cavity coupling and shuttles photons to the other empty cavity during every oscillation cycle in a well regulated fashion.

Huan Li; Mo Li

2014-09-03

415

Wavelet Methods in Statistics with R  

E-print Network

Use R! G.P.Nason Use R! Wavelet Methods in Statistics with R Wavelet for a number of disciplines including statistics. This book has three main objectives: (i) providing an introduction to wavelets and their uses in statistics; (ii) acting as a quick and broad reference to many

Nason, Guy

416

Quick statistics Survey 55563 'Privacy Survey'  

E-print Network

Quick statistics Survey 55563 'Privacy Survey' Results Survey 55563 Number of records in this query: 277 Total records in survey: 277 Percentage of total: 100.00% Page 1 / 94 #12;Quick statistics Survey 55563 'Privacy Survey' Page 2 / 94 #12;Quick statistics Survey 55563 'Privacy Survey' Field summary

Kaiser, Gail E.

417

ANTHROPOLOGICAL STATISTICS I THE UNIVERSITY OF TENNESSEE  

E-print Network

1 ANTHROPOLOGICAL STATISTICS I ANTH 504 THE UNIVERSITY OF TENNESSEE Instructor: Benjamin Auerbach Stadium Hall Course description: "There are three kinds of lies: lies, damn lies, and statistics." - Mark: statistics can be conducted on any set of numbers, but if the methods are used improperly, the results

Auerbach, Benjamin M.

418

Statistical mechanics of nonlinear elasticity Oliver Penrose  

E-print Network

Statistical mechanics of nonlinear elasticity Oliver Penrose Department of Mathematics, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK July 24, 2003 Running title: statistical mechanics Reviews classification numbers: 82B05 classical equilibrium statistical mechanics (general), 74B20

Penrose, Oliver

419

Statistics Department Feature SelectionFeature Selection  

E-print Network

;Wharton Statistics Department TCNJ January, 2005 5 DataData''s getting obese!s getting obese! NumberWharton Statistics Department Feature SelectionFeature Selection in Models For Data Miningin Models For Data Mining Robert Stine Statistics Department The Wharton School, Univ of Pennsylvania January, 2005

Stine, Robert A.

420

A square root analog to digital converter to optimally convert photonic signals for computed tomography  

E-print Network

The arrival of photons at a given location is a Poisson process with an associated shot noise which rises with the square root of the number of photons received. An analog-to-digital converter (ADC) with a square root ...

Bieniosek, Matthew (Matthew F.)

2010-01-01

421

A Photon Regeneration Experiment for Axion Search using X-rays R. Battesti,1,  

E-print Network

propagation in magnetic fields. PACS numbers: Photon propagation in magnetic fields is a long stand- ing looks for galactic cold dark matter µeV axion conversion into microwave photons in a res- onant cavity

422

Number Balance  

NSDL National Science Digital Library

This open-ended interactive Flash applet helps students develop operation and number sense, facility with number facts, and understanding of equations. Users designate single-digit whole numbers or integers and operations on both sides of an equation and test for balance. Users can enter numbers by using the keyboard or arrow buttons or by dragging number tiles. Each element can be hidden and a seesaw may be toggled on/off. Teachers may use this applet to lead instruction, or students may use it independently to perform specific investigations or explore freely. Supplementary documents include Objectives, containing teaching suggestions, and a student recording sheet.

Dan Bunker

2005-01-01

423

Photon: history, mass, charge  

E-print Network

The talk consists of three parts. ``History'' briefly describes the emergence and evolution of the concept of photon during the first two decades of the 20th century. ``Mass'' gives a short review of the literature on the upper limit of the photon's mass. ``Charge'' is a critical discussion of the existing interpretation of searches for photon charge. Schemes, in which all photons are charged, are grossly inconsistent. A model with three kinds of photons (positive, negative and neutral) seems at first sight to be more consistent, but turns out to have its own serious problems.

L. B. Okun

2006-02-03

424

Emitters of N-photon bundles  

NASA Astrophysics Data System (ADS)

Controlling the output of a light emitter is one of the basic tasks in photonics, with landmarks such as the development of the laser and single-photon sources. The ever growing range of quantum applications is making it increasingly important to diversify the available quantum sources. Here, we propose a cavity quantum electrodynamics scheme to realize emitters that release their energy in groups (or `bundles') of N photons (where N is an integer). Close to 100% of two-photon emission and 90% of three-photon emission is shown to be within reach of state-of-the-art samples. The emission can be tuned with the system parameters so that the device behaves as a laser or as an N-photon gun. Here, we develop the theoretical formalism to characterize such emitters, with the bundle statistics arising as an extension of the fundamental correlation functions of quantum optics. These emitters will be useful for quantum information processing and for medical applications.

Muñoz, C. Sánchez; Del Valle, E.; Tudela, A. González; Müller, K.; Lichtmannecker, S.; Kaniber, M.; Tejedor, C.; Finley, J. J.; Laussy, F. P.

2014-07-01

425

Photonic Doppler Velocimetry Multiplexing Techniques: Evaluation of Photonic Techniques  

SciTech Connect

This poster reports progress related to photonic technologies. Specifically, the authors developed diagnostic system architecture for a Multiplexed Photonic Doppler Velocimetry (MPDV) that incorporates frequency and time-division multiplexing into existing PDV methodology to provide increased channel count. Current MPDV design increases number of data records per digitizer channel 8x, and also operates as a laser-safe (Class 3a) system. Further, they applied heterodyne interferometry to allow for direction-of-travel determination and enable high-velocity measurements (>10 km/s) via optical downshifting. They also leveraged commercially available, inexpensive and robust components originally developed for telecom applications. Proposed MPDV architectures employ only commercially available, fiber-coupled hardware.

Edward Daykin

2012-05-24

426

Qudit-teleportation for photons with linear optics.  

PubMed

Quantum Teleportation, the transfer of the state of one quantum system to another without direct interaction between both systems, is an important way to transmit information encoded in quantum states and to generate quantum correlations (entanglement) between remote quantum systems. So far, for photons, only superpositions of two distinguishable states (one "qubit") could be teleported. Here we show how to teleport a "qudit", i.e. a superposition of an arbitrary number d of distinguishable states present in the orbital angular momentum of a single photon using d beam splitters and d additional entangled photons. The same entanglement resource might also be employed to collectively teleport the state of d/2 photons at the cost of one additional entangled photon per qubit. This is superior to existing schemes for photonic qubits, which require an additional pair of entangled photons per qubit. PMID:24686274

Goyal, Sandeep K; Boukama-Dzoussi, Patricia E; Ghosh, Sibasish; Roux, Filippus S; Konrad, Thomas

2014-01-01

427

Qudit-Teleportation for photons with linear optics  

NASA Astrophysics Data System (ADS)

Quantum Teleportation, the transfer of the state of one quantum system to another without direct interaction between both systems, is an important way to transmit information encoded in quantum states and to generate quantum correlations (entanglement) between remote quantum systems. So far, for photons, only superpositions of two distinguishable states (one ``qubit'') could be teleported. Here we show how to teleport a ``qudit'', i.e. a superposition of an arbitrary number d of distinguishable states present in the orbital angular momentum of a single photon using d beam splitters and d additional entangled photons. The same entanglement resource might also be employed to collectively teleport the state of d/2 photons at the cost of one additional entangled photon per qubit. This is superior to existing schemes for photonic qubits, which require an additional pair of entangled photons per qubit.

Goyal, Sandeep K.; Boukama-Dzoussi, Patricia E.; Ghosh, Sibasish; Roux, Filippus S.; Konrad, Thomas

2014-04-01

428

State-dependent photon blockade via quantum-reservoir engineering  

E-print Network

An arbitrary initial state of an optical or microwave field in a lossy driven nonlinear cavity can be changed, in the steady-state limit, into a partially incoherent superposition of only the vacuum and the single-photon states. This effect is known as single-photon blockade, which is usually analyzed for a Kerr-type nonlinear cavity parametrically driven by a single-photon process assuming single-photon loss mechanisms. We study photon blockade engineering via a squeezed reservoir, i.e., a quantum reservoir, where only two-photon absorption is allowed. Namely, we analyze a lossy nonlinear cavity parametrically driven by a two-photon process and allowing two-photon loss mechanisms, as described by the master equation derived for a two-photon absorbing reservoir. The nonlinear cavity engineering can be realized by a linear cavity with a tunable two-level system via the Jaynes-Cummings interaction in the dispersive limit. We show that by tuning properly the frequencies of the driving field and the two-level system, the steady state of the cavity field can be the single-photon Fock state or a partially incoherent superposition of several Fock states with photon numbers, e.g., (0,2), (1,3), (0,1,2), or (0,2,4). We observe that an arbitrary initial coherent or incoherent superposition of Fock states with an even (odd) number of photons can be changed into a partially incoherent superposition of a few Fock states of the same photon-number parity. A general solution for an arbitrary initial state is a weighted mixture of the above two solutions with even and odd photon numbers, where the weights are given by the probabilities of measuring the even and odd numbers of photons of the initial cavity field, respectively. Thus, in contrast to the standard photon blockade, we prove that the steady state in the engineered photon blockade, can depend on its initial state.

Adam Miranowicz; Jiri Bajer; Malgorzata Paprzycka; Yu-xi Liu; Alexandre M. Zagoskin; Franco Nori

2014-09-20

429

SOCR: Statistics Online Computational Resource  

PubMed Central

The need for hands-on computer laboratory experience in undergraduate and graduate statistics education has been firmly established in the past decade. As a result a number of attempts have been undertaken to develop novel approaches for problem-driven statistical thinking, data analysis and result interpretation. In this paper we describe an integrated educational web-based framework for: interactive distribution modeling, virtual online probability experimentation, statistical data analysis, visualization and integration. Following years of experience in statistical teaching at all college levels using established licensed statistical software packages, like STATA, S-PLUS, R, SPSS, SAS, Systat, etc., we have attempted to engineer a new statistics education environment, the Statistics Online Computational Resource (SOCR). This resource performs many of the standard types of statistical analysis, much like other classical tools. In addition, it is designed in a plug-in object-oriented architecture and is completely platform independent, web-based, interactive, extensible and secure. Over the past 4 years we have tested, fine-tuned and reanalyzed the SOCR framework in many of our undergraduate and graduate probability and statistics courses and have evidence that SOCR resources build student’s intuition and enhance their learning. PMID:21451741

Dinov, Ivo D.

2011-01-01

430

FIBONACCI NUMBERS, LUCAS NUMBERS AND INTEGRALS OF CERTAIN GAUSSIAN PROCESSES  

Microsoft Academic Search

We study the distributions of integrals of Gaussian processes aris- ing as limiting distributions of test statistics proposed for treating a goodness of t or symmetry problem. We show that the cumulants of the distributions can be expressed in terms of Fibonacci numbers and Lucas numbers. 1 n P n k=1 exp(it 0 Xk), t2 Rd, be the empirical Fourier

LUDWIG BARINGHAUS; Wei-Yin Loh

431

Number Sense  

NSDL National Science Digital Library

Students will practice counting to 100 and making numbers with base ten blocks Let\\'s have some fun with math! First, practice counting to 100. Listen to the instructions on this website. Count to 100 Now that you have worked on counting to 100, let\\'s make some numbers! Use the base ten blocks to make the numbers shown on the screen! Base Ten Blocks Great work! The next ...

Black, Mrs.

2007-10-03

432

Complex Numbers  

NSDL National Science Digital Library

The objective of this lesson is to gain a better understanding of complex numbers and their graphs Situation: The Swiss Mathemation, Jean Robert Argand developed a means to graphically represent complex numbers. This led to solving problems related to altenating electrical current, which provides current day luxuries. Could you do the same? Current Knowledge: Use your knowledge of complex number and the coordinate system and with your partner, ...

Mrs. Pierce

2010-11-16

433

National Statistical Service of Greece  

NSDL National Science Digital Library

Greece is one of the oldest countries in the world, and for those seeking current and historical information about the country in terms of a variety of statistics, this website will be quite useful. On the site, visitors can download a recent publication titled "Greece in Numbers" which is a 27-page document produced by the Statistical Service that features some basic demographic data, along with information about the country's manufacturing output and natural resources. Within the section titled "Statistical Data", visitors can also view more specialized data such as yearly information about the number of live births and the labor market. Visitors looking to learn about the new products released on the site should consult the "News" section or read through their press release section as well for various statistical indices.

434

Thiophene dendrimers as entangled photon sensor materials.  

PubMed

The ability to do spectroscopy with a small number of entangled photons is an important development in the area of materials and sensing. This report investigates the effects of increasing thiophene dendrimer generation on the cross-section for both entangled (sigmaE) and random (deltaE) two-photon absorption cross-sections. Nonlinear optical properties of dendrimers are an interesting area of study because of potential applications in optical signal processing and remote sensing, and the use of a nonlinear optical material as a sensor for entangled photons offers great possibilities for applications in quantum lithography. Entangled two-photon absorption (ETPA) experiments and two-photon excited fluorescence (TPEF) experiments vary by at least 10 orders of magnitude in the photon flux used to probe the material. ETPA cross-sections from liquid samples as well as those of thin-film samples are investigated. An increase in sigmaE and de;taR with increasing dendrimer generation is observed, suggesting that the thiophene groups within the dendrimer nonlinearly absorb in a cooperative manner, which is further evidenced in the variation of cross-section per thiophene group. The nonlinear spectroscopic features obtained by the TPEF measurements were also obtained by the ETPA experiments, despite the fact that 10 orders of magnitude fewer photons are used in the latter technique. All dendrimer generations investigated in this work are found to have great potential for applications in quantum optical devices. PMID:19123819

Harpham, Michael R; Süzer, Ozgün; Ma, Chang-Qi; Bäuerle, Peter; Goodson, Theodore

2009-01-28

435

Photon detection efficiency of Geiger-mode avalanche photodiodes  

E-print Network

The photon detection efficiencies of multi-pixel Geiger-mode avalanche photodiodes manufactured by different produ cers are estimated. A new fit method of the response spectra to low-intensity light, taking into ac count after-pulse and cross-talk effects is proposed to yield the initial number of photons. The value of photon detection efficiency is calculated using a calibrated photodetector as a reference.

Gentile, Simonetta; Meddi, Franco

2010-01-01

436

Canonical Phase Measurements in the Presence of Photon Loss  

E-print Network

We analyze the optimal state, as given by Berry and Wiseman [Phys. Rev. Lett {\\bf 85}, 5098, (2000)], under the canonical phase measurement in the presence of photon loss. The model of photon loss is a generic fictitious beam splitter, and we present the full density matrix calculations, which are more direct and do not involve any approximations. We find for a given amount of loss the upper bound for the input photon number that yields a sub-shot noise estimate.

Aravind Chiruvelli; Hwang Lee

2008-11-17

437

Study of squeezed state on free electron lasers 1 Work supported by the Office of Naval Research under grant Number N00014-94-1-0818. 1  

Microsoft Academic Search

Preliminary investigations on squeezed state of FEL have been undertaken at the Duke FEL lab by means of photon counting experiments. We report photon statistics for spontaneous undulator radiation from Duke Storage Ring. Photon counting measurements have also been constructed on the Mark III FEL to obtain the statistical behavior of the visible harmonics of the infrared radiation. The initial

Teng Chen; J. M. J. Madey

1998-01-01

438

Explorations in statistics: power  

NSDL National Science Digital Library

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This fifth installment of Explorations in Statistics revisits power, a concept fundamental to the test of a null hypothesis. Power is the probability that we reject the null hypothesis when it is false. Four things affect power: the probability with which we are willing to rejectÃÂby mistakeÃÂa true null hypothesis, the magnitude of the difference we want to be able to detect, the variability of the underlying population, and the number of observations in our sample. In an application to an Institutional Animal Care and Use Committee or to the National Institutes of Health, we define power to justify the sample size we propose.

Douglas Curran-Everett (University of Colorado Physiology and Biophysics)

2010-06-01

439

Index Numbers  

Microsoft Academic Search

Index numbers are used to aggregate detailed information on prices and quantities into scalar measures of price and quantity levels or their growth. The paper reviews four main approaches to bilateral index number theory where two price and quantity vectors are to be aggregated: fixed basket and average of fixed baskets, stochastic, test or axiomatic and economic approaches. The paper

Erwin Diewert

2007-01-01

440

Investigating the Randomness of Numbers  

ERIC Educational Resources Information Center

The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

Pendleton, Kenn L.

2009-01-01

441

On the main Errors underlying Statistical Physics  

NASA Astrophysics Data System (ADS)

The basis of statistical physics that was created by Maxwell, Boltzmann, Gibbs, Planck, Bose, Einstein, Fermi has been analyzed critically. The analysis is based on the concepts of discrete accidental quantity (the energy of the subsystem), statistical ensemble of identical systems and temperature. The key idea is that the expression for the distribution function (giving the complete quantum-statistical description of a subsystem) is the equation for the universal parameter the temperature T of the subsystems; in view of logic, the solution of the equation presents the quantum-statistical definition of T; the T is to characterize the empirically found general property of thermal processes (i.e., the T is not to depend on the structure of the energy spectrum of the subsystem). The results of the critical analysis are, in particular, as follows. (1) The energy of the subsystem must be counted off its least value. (2) The range of the parameter T of the subsystem is given by 0 < T < E_? where E_? is the boundary of the energy spectrum of the subsystem. If T = 0, then the description of the subsystem loses its statistical meaning because, in this case, the energy of the subsystem is not an accidental quantity (hence, the thermal energy of this subsystem equals zero). (3) The Boltzmann formula S = klogW, the Boltzmann-Gibbs and Einstein-Planck formulae for entropy S are incorrect. (4) The correct expression for the entropy of the subsystem has the form S = sumnolimitsn = 0^? S_nf_n, Sn ? E_n/T = - ln(f_n/f_0), n = 0, 1, ldots where E_n, fn are the energy of the subsystem and the Gibbs quantum canonical distribution, respectively. In the thermodynamical limit, S = 1 (therefore, thermodynamics should be corrected). (5) The Gibbs grand-canonical distribution, the Bose-Einstein and Fermi-Dirac distribution functions are incorrect because they contain the chemical potential ?. (6) The Einstein coefficients A_nm, B_nm, B_mn are different from zero only if A_nm ? B_nm ? B_mn ? P_nm^10 (where P_nm^q + 1, q is the (m, q) arrow (n, q + 1) transition probability in unit time; the quantum numbers q, q + 1 and m, n characterize the energetic states of the photon gas and of the molecule, respectively). Thus, the generally accepted basis of statistical physics includes the essential errors that are due to violation of the laws of logic. Correction of the errors open a way to unitarization of the principles of statistical physics and physical kinetics. (A more detailed consideration is given in a dissertation [T.Z.Kalanov, “The correct quantum-statistical description of the ideal systems within the framework of the master equation”, Tashkent, 1993]).

Kalanov, Temur Z.

2002-04-01

442

Orbital Angular Momentum of Gauge Fields: Excitation of an Atom by Twisted Photons  

SciTech Connect

Twisted photon states, or photon states with large (> {h_bar}) angular momentum projection in the direction of motion, can photoexcite atomic final states of differing quantum numbers. If the photon symmetry axis coincides with the center of an atom, there are known selection rules that require exact matching between the quantum numbers of the photon and the photoexcited states. The more general case of arbitrarily positioned beams relaxes the selection rules but produces a distribution of quantum numbers of the final atomic states that is novel and distinct from final states produced by plane-wave photons. Numerical calculations are presented using a hydrogen atom as an example.

Afanasev, Andrei V. [George Washington Univ., Washington, DC (United States); Carlson, Carl E. [William and Mary College, Williamsburg, VA and JLAB, Newport News, VA (United States); Mukherjee, Asmita [Indian Institute of Technology, Bombay (India)

2014-01-01

443

Monitoring molecular interactions using photon arrival-time interval distribution analysis  

DOEpatents

A method for analyzing/monitoring the properties of species that are labeled with fluorophores. A detector is used to detect photons emitted from species that are labeled with one or more fluorophores and located in a confocal detection volume. The arrival time of each of the photons is determined. The interval of time between various photon pairs is then determined to provide photon pair intervals. The number of photons that have arrival times within the photon pair intervals is also determined. The photon pair intervals are then used in combination with the corresponding counts of intervening photons to analyze properties and interactions of the molecules including brightness, concentration, coincidence and transit time. The method can be used for analyzing single photon streams and multiple photon streams.

Laurence, Ted A. (Livermore, CA); Weiss, Shimon (Los Angels, CA)

2009-10-06

444

Function photonic crystals  

NASA Astrophysics Data System (ADS)

In this paper, we present a new kind of function photonic crystals (PCs), whose refractive index is a function of space position. Conventional PCs structure grows from two materials, A and B, with different dielectric constants ?A and ?B. Based on Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we give the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals, and we find the following: (1) For the vertical and non-vertical incidence light of function photonic crystals, there are band gap structures, and for only the vertical incidence light, the conventional PCs have band gap structures. (2) By choosing various refractive index distribution functions n( z), we can obtain more wider or more narrower band gap structure than conventional photonic crystals.

Wu, Xiang-Yao; Zhang, Bai-Jun; Yang, Jing-Hai; Liu, Xiao-Jing; Ba, Nuo; Wu, Yi-Heng; Wang, Qing-Cai

2011-07-01

445

MQSA National Statistics  

MedlinePLUS

... MQSA) Scorecard Articles MQSA National Statistics MQSA National Statistics In this section of the MQSA Scorecard, we present the most commonly requested national statistics regarding the MQSA program. These statistics are updated ...

446

Two-photon physics  

SciTech Connect

A new experimental frontier has recently been opened to the study of two photon processes. The first results of many aspects of these reactions are being presented at this conference. In contrast, the theoretical development of research ito two photon processes has a much longer history. This talk reviews the many different theoretical ideas which provide a detailed framework for our understanding of two photon processes.

Bardeen, W.A.

1981-10-01

447

Photon-sieve lithography.  

PubMed

We present the first lithography results that use high-numerical-aperture photon sieves as focusing elements in a scanning-optical-beam-lithography system [J. Vac. Sci. Technol. B 21, 2810 (2003)]. Photon sieves are novel optical elements that offer the advantages of higher resolution and improved image contrast compared with traditional diffractive optics such as zone plates [Nature 414, 184 (2001)]. We fabricated the highest-numerical-aperture photon sieves reported to date and experimentally verified their focusing characteristics. We propose two new designs of the photon sieve that have the potential to significantly increase focusing efficiency. PMID:15717565

Menon, Rajesh; Gil, Dario; Barbastathis, George; Smith, Henry I

2005-02-01

448

Uncertainty relation for photons.  

PubMed

The uncertainty relation for the photons in three dimensions that overcomes the difficulties caused by the nonexistence of the photon position operator is derived in quantum electrodynamics. The photon energy density plays the role of the probability density in configuration space. It is shown that the measure of the spatial extension based on the energy distribution in space leads to an inequality that is a natural counterpart of the standard Heisenberg relation. The equation satisfied by the photon wave function in momentum space which saturates the uncertainty relations has the form of the Schrödinger equation in coordinate space in the presence of electric and magnetic charges. PMID:22540772

Bialynicki-Birula, Iwo; Bialynicka-Birula, Zofia

2012-04-01

449

VOLUME 80, NUMBER 2 P H Y S I C A L R E V I E W L E T T E R S 12 JANUARY 1998 Human Balance out of Equilibrium: Nonequilibrium Statistical Mechanics in Posture Control  

E-print Network

VOLUME 80, NUMBER 2 P H Y S I C A L R E V I E W L E T T E R S 12 JANUARY 1998 Human Balance out [13]. Here we apply the FDT to the human postural control system and use it to test the hypothesis multiple sensory systems and motor compo- nents. Numerous studies have investigated human balance control

Collins, James J.

450

Increased polarization-entangled photon flux via thinner crystals  

SciTech Connect

We analyze the scaling laws that govern the production of polarization-entangled photons via type-II spontaneous parametric down-conversion (SPDC). We demonstrate experimentally that thin nonlinear crystals can generate a higher number of entangled photons than thicker crystals, basically because they generate a broader spectrum.

Lee, P.S.K.; Exter, M.P. van; Woerdman, J.P. [Leiden University, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden (Netherlands)

2004-10-01

451

Number Line  

NSDL National Science Digital Library

In this brief article the numerous uses of the number line are detailed: counting, measurement, addition, subtraction, decimals, and fractions. The article contains visual representations of the some of the concepts and links to related topics.

2012-08-27

452

Complex Numbers  

NSDL National Science Digital Library

Written by Tony R. Kuphaldt and Jason Starck, this chapter of All About Circuit's second volume on Alternating Current describes complex numbers: "In order to successfully analyze AC circuits, we need to work with mathematical objects and techniques capable of representing these multi-dimensional quantities. Here is where we need to abandon scalar numbers for something better suited: complex numbers." In addition to the introduction and credits to contributors, the chapter has seven sections: Vectors and AC waveforms, Simple vector addition, Complex vector addition, Polar and rectangular notation, Complex number arithmetic, More on AC "polarity," and Some examples with AC circuits. Each section has clear illustrations and a concise, bulleted review of what was covered at the end.

Kuphaldt, Tony R.

2008-07-15

453

OECD Regional Statistics  

NSDL National Science Digital Library

Interactive resource codes either "OECD large regions" usually the primary subnational administrative unit of an OECD country -- (eg. states) or "OECD small regions" usually the secondary subnmational administrative unit -- (eg. counties) by demographic, economic and educational statistics. Regions are compared on a color coded map (for any single variable), scatter plot (for any two variables, table lens or data grid (for a large number of variables. Allows transnational comparisons across all rich countries, but also allows the specificity of focusing on subnational -- and sometimes very small -- geographic units.

Development, Organisation F.

454

Statistics of Crumpled Paper  

NASA Astrophysics Data System (ADS)

A statistical study of crumpled paper is allowed by a minimal 1D model: a self-avoiding line bent at sharp angles—in which the elastic energy resides—put in a confining potential. Many independent equilibrium configurations are generated numerically and their properties are investigated. At small confinement, the distribution of segment lengths is log-normal in agreement with previous predictions and experiments. At high confinement, the system approaches a jammed state with a critical behavior, whereas the length distribution follows a gamma law in which the parameter is predicted as a function of the number of layers in the system.

Sultan, Eric; Boudaoud, Arezki

2006-04-01

455

Deterministic photon-emitter coupling in chiral photonic circuits  

E-print Network

The ability to engineer photon emission and photon scattering is at the heart of modern photonics applications ranging from light harvesting, through novel compact light sources, to quantum-information processing based on single photons. Nanophotonic waveguides are particularly well suited for such applications since they confine photon propagation to a 1D geometry thereby increasing the interaction between light and matter. Adding chiral functionalities to nanophotonic waveguides lead to new opportunities enabling integrated and robust quantum-photonic devices or the observation of novel topological photonic states. In a regular waveguide, a quantum emitter radiates photons in either of two directions, and photon emission and absorption are reverse processes. This symmetry is violated in nanophotonic structures where a non-transversal local electric field implies that both photon emission and scattering may become directional. Here we experimentally demonstrate that the internal state of a quantum emitter determines the chirality of single-photon emission in a specially engineered photonic-crystal waveguide. Single-photon emission into the waveguide with a directionality of more than 90\\% is observed under conditions where practically all emitted photons are coupled to the waveguide. Such deterministic and highly directional photon emission enables on-chip optical diodes, circulators operating at the single-photon level, and deterministic quantum gates. Based on our experimental demonstration, we propose an experimentally achievable and fully scalable deterministic photon-photon CNOT gate, which so far has been missing in photonic quantum-information processing where most gates are probabilistic.

Immo Söllner; Sahand Mahmoodian; Sofie Lindskov Hansen; Leonardo Midolo; Alisa Javadi; Gabija Kiršansk?; Tommaso Pregnolato; Haitham El-Ella; Eun Hye Lee; Jin Dong Song; Søren Stobbe; Peter Lodahl

2015-01-12

456

Stupid statistics!  

PubMed

The method of least squares is probably the most powerful data analysis tool available to scientists. Toward a fuller appreciation of that power, this work begins with an elementary review of statistics fundamentals, and then progressively increases in sophistication as the coverage is extended to the theory and practice of linear and nonlinear least squares. The results are illustrated in application to data analysis problems important in the life sciences. The review of fundamentals includes the role of sampling and its connection to probability distributions, the Central Limit Theorem, and the importance of finite variance. Linear least squares are presented using matrix notation, and the significance of the key probability distributions-Gaussian, chi-square, and t-is illustrated with Monte Carlo calculations. The meaning of correlation is discussed, including its role in the propagation of error. When the data themselves are correlated, special methods are needed for the fitting, as they are also when fitting with constraints. Nonlinear fitting gives rise to nonnormal parameter distributions, but the 10% Rule of Thumb suggests that such problems will be insignificant when the parameter is sufficiently well determined. Illustrations include calibration with linear and nonlinear response functions, the dangers inherent in fitting inverted data (e.g., Lineweaver-Burk equation), an analysis of the reliability of the van't Hoff analysis, the problem of correlated data in the Guggenheim method, and the optimization of isothermal titration calorimetry procedures using the variance-covariance matrix for experiment design. The work concludes with illustrations on assessing and presenting results. PMID:17964948

Tellinghuisen, Joel

2008-01-01

457

Diagnosis of multilayer clouds using photon path length distributions  

NASA Astrophysics Data System (ADS)

Photon path length distribution is sensitive to 3-D cloud structures. A detection method for multilayer clouds has been developed, by utilizing the information of photon path length distribution. The photon path length method estimates photon path length information from the low level, single-layer cloud structure that can be accurately observed by a millimeter-wave cloud radar (MMCR) combined with a micropulse lidar (MPL). As multiple scattering within the cloud layers and between layers would substantially enhance the photon path length, the multilayer clouds can be diagnosed by evaluating the estimated photon path information against observed photon path length information from a co-located rotating shadowband spectrometer (RSS). The measurements of MMCR-MPL and RSS at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site have been processed for the year 2000. Cases studies illustrate the consistency between MMCR-MPL detection and the photon path length method under most conditions. However, the photon path length method detected some multilayer clouds that were classified by the MMCR-MPL as single-layer clouds. From 1 year statistics at the ARM SGP site, about 27.7% of single-layer clouds detected by the MMCR-MPL with solar zenith angle less than 70° and optical depth greater than 10 could be multilayer clouds. It suggests that a substantial portion of single-layer clouds detected by the MMCR-MPL could also be influenced by some "missed" clouds or by the 3-D effects of clouds.

Li, Siwei; Min, Qilong

2010-10-01

458

Boson sampling with photons of arbitrary spectral structure  

NASA Astrophysics Data System (ADS)

Boson sampling has attracted much interest as a simplified approach to implementing a subset of optical quantum computing. Boson sampling requires indistinguishable photons, but far fewer of them than universal optical quantum computing architectures. In reality, photons are never indistinguishable, and exhibit a rich spectral structure. Here we consider the operation of boson sampling with photons of arbitrary spectral structure and relate the sampling statistics of the device to matrix permanents. This sheds light on the computational complexity of different regimes of the photons' spectral characteristics, and provides very general results for the operation of linear optics interferometers in the presence of partially distinguishable photons. Our results apply to both the cases of spectrally resolving and nonspectrally resolving detectors.

Rohde, Peter P.

2015-01-01

459

Precise Monte Carlo Simulation of Single-Photon Detectors  

E-print Network

We demonstrate the importance and utility of Monte Carlo simulation of single-photon detectors. Devising an optimal simulation is strongly influenced by the particular application because of the complexity of modern, avalanche-diode-based single-photon detectors.. Using a simple yet very demanding example of random number generation via detection of Poissonian photons exiting a beam splitter, we present a Monte Carlo simulation that faithfully reproduces the serial autocorrelation of random bits as a function of detection frequency over four orders of magnitude of the incident photon flux. We conjecture that this simulation approach can be easily modified for use in many other applications.

Mario Stip?evi?; Daniel J. Gauthier

2014-11-13

460

Thermal photon v2 with slow quark chemical equilibration  

NASA Astrophysics Data System (ADS)

Elliptic flow of direct photons in high-energy heavy-ion collisions has been a topic of great interest since it was experimentally found to be larger than most hydrodynamic expectations. I discuss the implication of possible late formation of the quark component in a hot QCD medium on the photon elliptic flow, because quarks are the source of thermal photons in the deconfined phase. Hydrodynamic equations are numerically solved with the evolution equations for quark and gluon number densities. The numerical results suggest that thermal photon v2 is visibly enhanced by the slow chemical equilibration of quarks and gluons, reducing the aforementioned problem.

Monnai, Akihiko

2014-08-01

461

On statistical information of extreme order statistics, local extreme value alternatives, and poisson point processes  

Microsoft Academic Search

The aim of the present paper is to clarify the rôle of extreme order statistics in general statistical models. This is done within the general setup of statistical experiments in LeCam's sense. Under the assumption of monotone likelihood ratios, we prove that a sequence of experiments is asymptotically Gaussian if, and only if, a fixed number of extremes asymptotically does

A. Janssen; F. Marohn

1994-01-01

462

[Estimated numbers of visceral mycoses in cases of leukemia and MDS in Japan : analysis of data from the Annual of Pathological Autopsy Cases and the vital statistics published by Ministry of health, labour and welfare in Japan].  

PubMed

Our analysis reported here, is the first one in the world to make a nationwide-level estimate on numbers of visceral mycoses in case of leukemia and myelodysplastic syndrome (MDS)in Japan. The data on visceral mycoses in cases reported in the" Annual of the Pathological Autopsy Cases in Japan" published by the Japanese society of pathology in 2002 and 2006, and the data in the vital statics in Japan published by Ministry of health, labour and welfare were analyzed epidemiologically. The estimated numbers of visceral mycoses were 2,250 out of the estimated total death 8,976 in 2001, and 2290 out of 9,805 in 2005, respectively, in cases of leukemia and MDS in Japan. Furthermore, the estimated severe cases that we thought direct cause of death were 1,454 in 2001, and 1,464 in 2005, respectively. In the severe cases, the most causative agents were Aspergillus. The estimated numbers of Candida and Zygomycetes were interestingly almost same in the severe cases, but the lethal rate in Zygomycetes was about 60-80 % , almost twice as that in Candida. We think it is imperative to continuously survey and watch these rates towards the future. PMID:22467132

Togano, Tomiteru; Shibuya, Kazutoshi; Kume, Hikaru

2012-01-01

463

Resonances in photon-photon scattering  

SciTech Connect

Selected topics in meson spectroscoy are reviewed as they are illuminated by photon-photon collisons. Subjects include the S*/f/sub 0/ (975) and delta/a/sub 0/ (980) as /ovr qq/qq candidates, the /iota///eta/ (1460) and theta/f/sub 2/ (1700) as glueball candidates, and the spin 1 X(1420) seen in tagged events which represents new physics whether its parity is positive, J/sup PC/ = 1/sup + +/, or negative with exotic J/sup PC/ = 1/sup /minus/+/. 57 refs., 2 figs., 1 tab.

Chanowitz, M.S.

1988-06-01

464

Photon beam position monitor  

DOEpatents

A photon beam position monitor is disclosed for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade ''shadowing''. Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation. 18 figs.

Kuzay, T.M.; Shu, D.

1995-02-07

465

Photon beam position monitor  

DOEpatents

A photon beam position monitor for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade "shadowing". Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation.

Kuzay, Tuncer M. (Naperville, IL); Shu, Deming (Darien, IL)

1995-01-01

466

Photonic layered media  

DOEpatents

A new class of structured dielectric media which exhibit significant photonic bandstructure has been invented. The new structures, called photonic layered media, are easy to fabricate using existing layer-by-layer growth techniques, and offer the ability to significantly extend our practical ability to tailor the properties of such optical materials.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM)

2002-01-01

467

A novel photonic oscillator  

NASA Technical Reports Server (NTRS)

We report a novel oscillator for photonic RF systems. This oscillator is capable of generating high-frequency signals up to 70 GHz in both electrical and optical domains and is a special voltage-controlled oscillator with an optical output port. It can be used to make a phase-locked loop (PLL) and perform all functions that a PLL is capable of for photonic systems. It can be synchronized to a reference source by means of optical injection locking, electrical injection locking, and PLL. It can also be self-phase locked and self-injection locked to generate a high-stability photonic RF reference. Its applications include high-frequency reference regeneration and distribution, high-gain frequency multiplication, comb-frequecy and square-wave generation, carrier recovery, and clock recovery. We anticipate that such photonic voltage-controlled oscillators (VCOs) will be as important to photonic RF systems as electrical VCOs are to electrical RF systems.

Yao, X. S.; Maleki, L.

1995-01-01

468

Solar Photon Random Walk  

NSDL National Science Digital Library

The Solar Photon Random Walk Model simulates the path of photons in radiative transport as they escape from the Sun. Photons do not travel in a straight line, but rather collide with larger particles and get redirected. This simulation models that process using a random walk in polar coordinates. The random walk parameters are adjustable to match different models of the structure of the sun, or the user can input their own values. The Solar Photon Random Walk Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_comp_phys_photon_random_walk.jar file will run the program if Java is installed.

Onken, Ew

2011-07-26

469

Waves and Photons  

NSDL National Science Digital Library

This lesson introduces students to electromagnetic waves, the concept of photons, and the relation between photon wavelength and energy. This is tied to solar observations at various wavelengths using the many types of electromagnetic waves. Students will discover that electromagnetic waves are a linked oscillation of magnetic fields and electric currents, spreading through space. They will also discover that although light spreads like a wave, it only gives up its energy in well-defined amounts, known as photons, and when an individual atom emits light, it usually changes from some excited state of higher energy to one with lower energy. The energy (color) of the emitted photon is very precisely determined by the difference between those levels and the shorter the wavelength, the bigger the photon energy. Thus hot regions of the Sun, whose atoms move faster and therefore have more energy, are likely to emit shorter wavelengths. The work of James Clerk Maxwell and Heinrich Hertz is also discussed.

David Stern

470

Ion photon emission microscope  

DOEpatents

An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

Doyle, Barney L. (Albuquerque, NM)

2003-04-22

471

Photonic quantum technologies  

E-print Network

The first quantum technology, which harnesses uniquely quantum mechanical effects for its core operation, has arrived in the form of commercially available quantum key distribution systems that achieve enhanced security by encoding information in photons such that information gained by an eavesdropper can be detected. Anticipated future quantum technologies include large-scale secure networks, enhanced measurement and lithography, and quantum information processors, promising exponentially greater computation power for particular tasks. Photonics is destined for a central role in such technologies owing to the need for high-speed transmission and the outstanding low-noise properties of photons. These technologies may use single photons or quantum states of bright laser beams, or both, and will undoubtably apply and drive state-of-the-art developments in photonics.

Jeremy L. O'Brien; Akira Furusawa; Jelena Vu?kovi?

2010-03-20

472

Photons at PHENIX  

E-print Network

Direct photons are a powerful probe to study the properties of the unique matter created in ultrarelativistic heavy-ion collisions. They carry information on the various stages of a heavy-ion collision. At different transverse momenta (pT), different production processes dominate the direct photon yield in heavy-ion collisions. Photons at high pT can be used to study initial hard scattering processes while photons at low and intermediate pT provide direct information on the hot and dense medium created in such collisions since they origin predominantly from jet-medium interactions and from thermal radiation from the medium itself. PHENIX has measured direct-photon yields over a broad pT and energy range in different collision systems such as Au+Au and Cu+Cu, allowing systematic studies of the behavior of direct photons in heavy-ion collisions. Two different methods have been used to measure the direct photons. An excess of direct photons in Au+Au collisions at low pT beyond the expectation from p+p collisions was measured for the first time via internal conversion. Furthermore, the azimuthal anisotropy parameter v2 has been measured. The direct photon v2 sheds light on the different processes contributing to the production of direct photons. The p+p data at the same energy provide a baseline for understanding the heavy-ion data, but are also interesting in their own right, e.g. for testing pQCD calculations or - as RHIC collides polarized protons - for constraining models on the gluon contribution to the proton spin.

Baldo Sahlmueller; for the PHENIX collaboration

2009-04-30

473

Numbers Sense  

ERIC Educational Resources Information Center

This article reports on work undertaken by schools as part of Qualifications and Curriculum Authority's (QCA's) "Engaging mathematics for all learners" project. The goal was to use in the classroom, materials and approaches from a Royal Institution (Ri) Year 10 master-class, "Number Sense", which was inspired by examples from Michael Blastland and…

Kathotia, Vinay

2009-01-01

474

Numbers & Operation  

NSDL National Science Digital Library

Let's get speedy with number use. Click on the game Going Bananas with Divsion which is in bold letters below. Using the mouse, click on Instructions and read them carefully. Then, click on Start Game . Then select 3-12 as your level to play. Use the mouse to select ...

Mrs. Fincher

2010-03-07

475

Number Patterns  

NSDL National Science Digital Library

In this lesson, learners are challenged to discover the relationship among six numbers. The objective of this activity is to engage learners in a problem-solving situation in which they practice aspects of the process of science. Learners can use an included Science Flowchart to chart their scientific experience. This lesson serves as a good introduction to the nature of scientific inquiry.

Scotchmoor, Judy

2010-01-01