NASA Astrophysics Data System (ADS)
Gaidash, A. A.; Egorov, V. I.; Gleim, A. V.
2014-10-01
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.
Observation of grand-canonical number statistics in a photon Bose-Einstein condensate.
Schmitt, Julian; Damm, Tobias; Dung, David; Vewinger, Frank; Klaers, Jan; Weitz, Martin
2014-01-24
We report measurements of particle number correlations and fluctuations of a photon Bose-Einstein condensate in a dye microcavity using a Hanbury Brown-Twiss experiment. The photon gas is coupled to a reservoir of molecular excitations, which serve as both heat bath and particle reservoir to realize grand-canonical conditions. For large reservoirs, we observe strong number fluctuations of the order of the total particle number extending deep into the condensed phase. Our results demonstrate that Bose-Einstein condensation under grand-canonical ensemble conditions does not imply second-order coherence. PMID:24484122
Generalized binomial distribution in photon statistics
Aleksey Ilyin
2014-11-20
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.
NASA Astrophysics Data System (ADS)
Pastukhov, Vladimir M.; Vladimirova, Yulia V.; Zadkov, Victor N.
2014-12-01
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.
Photon statistics dispersion in excitonic composites
G. Ya. Slepyan; S. A. Maksimenko
2006-05-22
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.
Jan Perina; Jaromir Krepelka; Jan Perina Jr; Maria Bondani; Alessia Allevi; Alessandra Andreoni
2007-08-16
Joint signal-idler photoelectron distributions of twin beams containing several tens of photons per mode have been measured recently. Exploiting a microscopic quantum theory for joint quasi-distributions in parametric down-conversion developed earlier we characterize properties of twin beams in terms of quasi-distributions using experimental data. Negative values as well as oscillating behaviour in quantum region are characteristic for the subsequently determined joint signal-idler quasi-distributions of integrated intensities. Also the conditional and difference photon-number distributions are shown to be sub-Poissonian and sub-shot-noise, respectively.
How we know that photons are bosons: experimental tests of spin-statistics for photons
Pines, Alexander
How we know that photons are bosons: experimental tests of spin-statistics for photons D. DeMille,1 that shed light on possible small violations of the spin-statistics relation for photons. Particular of the usual spin-statistics relation, for a number of reasons. The photon is of course the only fundamental
Characterization of photon statistics in a single-photon source via variable attenuation
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
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.
Tunable photon statistics in weakly nonlinear photonic molecules
Xun-Wei Xu; Yong Li
2014-07-11
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.
Fluctuations in particle number for a photon gas
NASA Astrophysics Data System (ADS)
Leff, Harvey S.
2015-04-01
The fluctuation-compressibility theorem of statistical mechanics states that fluctuations in particle number are proportional to the isothermal compressibility. Given that the compressibility of a photon gas does not exist, this seems to suggest that fluctuations in photon number similarly do not exist. However, it is shown here that the fluctuation-compressibility theorem does not hold for photons and, in fact, that fluctuations do exist.
The Influence of Multi-Photon Absorption on Photon Statistics
Ulrike Mohr; Harry Paul
1978-01-01
A previous approximation scheme [6] which allowed to calculate, in a simple manner, the quantity n2\\/ ( mean value and n2 variance of the photon number) in the course of a multi-photon absorption process, is extended to study the change of the shape of the photon distribution, too. It turns out that there is a tendency to symmetrize the distribution.
Laser photon statistics in the feedback loop
T. Yu. Golubeva; Yu. M. Golubev
2005-04-23
A mere correspondence between the electron statistics and the photon one vanishes in the feedback loop (FBL). It means that the direct photodetection, supplying us with the electron statistics, does not provide us with a wished information about the laser photon statistics. For getting this information we should think up another measurement procedure, and we in the article suggest applying the three-level laser as a auxiliary measuring device. This laser has impressive property, namely, its photon statistics survive information about the initial photon statistics of the laser which excites coherently the three-level medium. Thus, if we choose the laser in the FBL as exciting the three-level laser, then we have an possibility to evaluate its initial photon statistics by means of direct detecting the three-level laser emission. Finally, this approach allows us to conclude the feedback is not capable of creating a regularity in the laser light beam. Contrary, the final photon fluctuations turn out to be always even bigger. The mentioned above feature of the three-level laser takes place only for the strong interaction between the lasers (exciting and excited). It means the initial state of the exciting laser is changed dramatically, so our measurement procedure can not be identified with some non-demolition one.
Observing fermionic statistics with photons in arbitrary processes
Matthews, Jonathan C. F.; Poulios, Konstantinos; Meinecke, Jasmin D. A.; Politi, Alberto; Peruzzo, Alberto; Ismail, Nur; Wörhoff, Kerstin; Thompson, Mark G.; O'Brien, Jeremy L.
2013-01-01
Quantum mechanics defines two classes of particles-bosons and fermions-whose exchange statistics fundamentally dictate quantum dynamics. Here we develop a scheme that uses entanglement to directly observe the correlated detection statistics of any number of fermions in any physical process. This approach relies on sending each of the entangled particles through identical copies of the process and by controlling a single phase parameter in the entangled state, the correlated detection statistics can be continuously tuned between bosonic and fermionic statistics. We implement this scheme via two entangled photons shared across the polarisation modes of a single photonic chip to directly mimic the fermion, boson and intermediate behaviour of two-particles undergoing a continuous time quantum walk. The ability to simulate fermions with photons is likely to have applications for verifying boson scattering and for observing particle correlations in analogue simulation using any physical platform that can prepare the entangled state prescribed here. PMID:23531788
Photon-number tomography and fidelity
O. V. Man'ko
2012-12-23
The scheme of photon-number tomography is discussed in the framework of star-product quantization. The connection of dual quantization scheme and observables is reviewed. The quantizer and dequantizer operators and kernels of star product of tomograms in photon-number tomography scheme and its dual one are presented in explicit form. The fidelity and state purity are discussed in photon{number tomographic scheme, and the expressions for fidelity and purity are obtained in the form of integral of the product of two photon-number tomograms with integral kernel which is presented in explicit form. The properties of quantumness are discussed in terms of inequalities on state photon{number tomograms.
Counting statistics of collective photon transmissions
Malte Vogl; Gernot Schaller; Tobias Brandes
2011-07-28
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 $N^2$ in the current and 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.
Photon statistics of a non-stationary periodically driven single-photon source
M. Hennrich; T. Legero; A. Kuhn; G. Rempe
2004-01-01
We investigate the photon statistics of a single-photon source that operates\\u000aunder non-stationary conditions. The photons are emitted by shining a periodic\\u000asequence of laser pulses on single atoms falling randomly through a\\u000ahigh-finesse optical cavity. Strong antibunching is found in the intensity\\u000acorrelation of the emitted light, demonstrating that a single atom emits\\u000aphotons one-by-one. However, the number of
Correlations in Single Molecule Photon Statistics: Renewal Indicator Jianshu Cao
Cao, Jianshu
Correlations in Single Molecule Photon Statistics: Renewal Indicator Jianshu Cao Department be revealed through single molecule photon statistical analysis. The standard Poisson indicator defined the transfer matrix method to demonstrate the difference between the two indicators. The relationship between
Counting statistics of collective photon transmissions
Vogl, M., E-mail: malte.vogl@tu-berlin.de; Schaller, G., E-mail: gernot.schaller@tu-berlin.de; Brandes, T.
2011-10-15
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.
Fast recognition of single molecules based on single event photon statistics
Shuangli Dong; Tao Huang; Yuan Liu; Jun Wang; Guofeng Zhang; Liantuan Xiao+; Suotang Jia
2007-08-02
Mandel Q-parameter, which is determined from single event photon statistics, provides an alternative to differentiate single-molecule with fluorescence detection. In this work, by using the Q-parameter of the sample fluorescence compared to that of an ideal double-molecule system with the same average photon number, we present a novel and fast approach for identifying single molecules based on single event photon statistics analyses, compared with commonly used two-time correlation measurements. The error estimates for critical values of photon statistics are also presented for single-molecule determination.
Photon statistics: Nonlinear spectroscopy of single quantum systems Shaul Mukamel
Mukamel, Shaul
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
Nonlinearity sensing via photon-statistics excitation spectroscopy
Assmann, Marc; Bayer, Manfred [Experimentelle Physik 2, Technische Universitaet Dortmund, D-44221 Dortmund (Germany)
2011-11-15
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.
Interaction of Fixed Number of Photons with Retinal Rod Cells
NASA Astrophysics Data System (ADS)
Phan, Nam Mai; Cheng, Mei Fun; Bessarab, Dmitri A.; Krivitsky, Leonid A.
2014-05-01
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.
Induced photon statistics in three-level lasers
T. Golubeva; Yu. Golubev
2006-04-12
The statistical properties of three-level lasing are investigated theoretically. It is assumed that the three-level medium is coherently excited by another laser with an arbitrary photon statistics. It is proved that, under the specific conditions, the photon statistics of the three-level laser duplicate the photon statistics of the exciting laser. We call this phenomenon an induced photon statistics. We suggest to use this to analyze the statistical properties of a laser involved into a feedback process. Applying this laser for the coherent pump of a three-level laser, we can follow its photon statistics by means of direct following the three-level generation. In accordance with [H. M. Wiseman and G. J. Milburn, Phys. Rev. A, 49, 1350-1366 (1994)], we conclude that the feedback in itself is unable to generate the non-classical manifestation in the laser field.
Linking numbers, spin, and statistics of solitons
NASA Technical Reports Server (NTRS)
Wilczek, F.; Zee, A.
1983-01-01
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.
Ideal photon number amplifier and duplicator
NASA Technical Reports Server (NTRS)
Dariano, G. M.
1992-01-01
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.
Cao, Hui
. The second-order correlation coefficient drops gradually from 2 to 1. By comparing the photon statistics in diameter on the sample surface. Another lens collects the sample emission in a single transverse mode to a fast pho- todiode whose output signal triggers the streak camera. A Peltier-cooled charge
Statistical Applets: Law of Large Numbers
NSDL National Science Digital Library
Duckworth, William
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.
Laser ranging at few-photon level by photon-number-resolving detection.
Bao, Zeyu; Liang, Yan; Wang, Zhiyuan; Li, Zhaohui; Wu, E; Wu, Guang; Zeng, Heping
2014-06-20
Sensitive laser ranging was demonstrated at few-photon level using photon-number-resolving (PNR) detectors. The reflected photon pulses from a non-cooperation remote target were distinguished in a sunlight environment of 2.5×103??lx by setting the discrimination threshold at 5-photon level. By comparing the detected photon numbers, two remote targets with different reflection coefficients were well recognized. PNR detection facilitated remote laser ranging of few-photon sensitivity with similar capabilities of linear optical detectors. This technique avoids photon-counting saturation and is important for ultra-long distance LIDAR and 3D imaging at a few photon level. PMID:24979422
Testing Photons' Bose-Einstein Statistics With Compton Scattering
Brett Altschul
2010-08-27
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^(-25) if Lorentz symmetry is required. If there is instead a universal preferred frame, the bound is nu < 10^(-14), still strong compared with previous results.
Photon number squeezed states in semiconductor lasers
NASA Technical Reports Server (NTRS)
Yamamoto, Yoshihisa; Machida, Susumu; Richardson, Wayne H.
1992-01-01
Electromagnetic fields, with the noise on one quadrature component reduced to below the quantum mechanical zero-point fluctuation level and the noise on the other quadrature component enhanced to above it, are currently of great interest in quantum optics because of their potential applications to various precision measurements. Such squeezed states of light are usually produced by imposing nonlinear unitary evolution on coherent (or vacuum) states. On the other hand, squeezed states with reduced photon number noise and enhanced phase noise are generated directly by a constant current-driven semiconductor laser. This is the simplest scheme for the generation of nonclassical light, and so far it has yielded the largest quantum noise reduction. The mutual coupling between a lasing junction and an external electrical circuit provides opportunities for exploring the macroscopic and microscopic quantum effects in open systems.
Significant Figures of Numbers in Statistical Tables
S. A. Goudsmit; W. H. Furry
1944-01-01
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.
Photon statistics of atomic fluorescence after {pi}-pulse excitation
Yoshimi, Kazuyoshi [College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Ichikawa, Chiba 272-0827 (Japan); Koshino, Kazuki [College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Ichikawa, Chiba 272-0827 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan)
2010-09-15
The photon statistics of atomic fluorescence after {pi}-pulse excitation is investigated in a system in which the input and output ports are connected to an atom. Since spontaneous decay during input pulse excitation occurs, the output pulse generally contains a multiphoton component with a certain probability. We quantitatively evaluate the probability of the output pulse containing multiple photons and determine the conditions for ideal single-photon generation.
Photon statistics of coherent harmonic radiation of a linac free electron laser
NASA Astrophysics Data System (ADS)
Chen, Teng
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.
Imaging with a small number of photons
NASA Astrophysics Data System (ADS)
Morris, Peter A.; Aspden, Reuben S.; Bell, Jessica E. C.; Boyd, Robert W.; Padgett, Miles J.
2015-01-01
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.
Imaging with a small number of photons
Morris, Peter A.; Aspden, Reuben S.; Bell, Jessica E. C.; Boyd, Robert W.; Padgett, Miles J.
2015-01-01
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. PMID:25557090
Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei
2015-01-01
Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2?K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77?K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. PMID:25797442
Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei
2015-01-01
Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn “photon-switches” to “OFF” state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2?K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77?K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. PMID:25797442
Photon statistics of a two-mode squeezed vacuum
NASA Technical Reports Server (NTRS)
Schrade, Guenter; Akulin, V. M.; Schleich, W. P.; Manko, Vladimir I.
1994-01-01
We investigate the general case of the photon distribution of a two-mode squeezed vacuum and show that the distribution of photons among the two modes depends on four parameters: two squeezing parameters, the relative phase between the two oscillators and their spatial orientation. The distribution of the total number of photons depends only on the two squeezing parameters. We derive analytical expressions and present pictures for both distributions.
Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength
Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide
2014-01-01
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
Photon-number-resolving detector with 10 bits of resolution
Jiang, Leaf A.; Dauler, Eric A.; Chang, Joshua T
2007-06-15
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.
Photon counting statistics analysis of biophotons from hands.
Jung, Hyun-Hee; Woo, Won-Myung; Yang, Joon-Mo; Choi, Chunho; Lee, Jonghan; Yoon, Gilwon; Yang, Jong S; Soh, Kwang-Sup
2003-05-01
The photon counting statistics of biophotons emitted from hands is studied with a view to test its agreement with the Poisson distribution. The moments of observed probability up to seventh order have been evaluated. The moments of biophoton emission from hands are in good agreement while those of dark counts of photomultiplier tube show large deviations from the theoretical values of Poisson distribution. The present results are consistent with the conventional delta-value analysis of the second moment of probability. PMID:15244266
Statistics and Modeling Unique Numbers 72100
Ghosh, Joydeep
the signup code 3N46J6F to create an account. Instead of your last name, enter your UTEID. COMPUTINGG@mail.utexas.edu TEACHING ASSISTANT Prana Narayanan Hours: Tuesday, Thursday 2:30 4:00 pm Office: CBA 4.304A Space B with Excel and elementary statistics. ASSIGNMENTS: I will assign frequent homework assignments
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...
Mean photon number dependent variational method to the Rabi model
NASA Astrophysics Data System (ADS)
Liu, Maoxin; Ying, Zu-Jian; An, Jun-Hong; Luo, Hong-Gang
2015-04-01
We present a mean photon number dependent variational method, which works well in the whole coupling regime if the photon energy is dominant over the spin-flipping, to evaluate the properties of the Rabi model for both the ground state and excited states. For the ground state, it is shown that the previous approximate methods, the generalized rotating-wave approximation (only working well in the strong coupling limit) and the generalized variational method (only working well in the weak coupling limit), can be recovered in the corresponding coupling limits. The key point of our method is to tailor the merits of these two existing methods by introducing a mean photon number dependent variational parameter. For the excited states, our method yields considerable improvements over the generalized rotating-wave approximation. The variational method proposed could be readily applied to more complex models, for which it is difficult to formulate an analytic formula.
Sum-frequency generation from photon number squeezed light
NASA Technical Reports Server (NTRS)
Wu, Ling-An; Du, Cong-Shi; Wu, Mei-Juan; Li, Shi-Qun
1994-01-01
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.
Decoy state quantum key distribution with a photon number resolved heralded single photon source
NASA Astrophysics Data System (ADS)
Horikiri, Tomoyuki; Kobayashi, Takayoshi
2006-03-01
Recently a long distance and high key rate quantum key distribution (QKD) has become possible by the idea of the decoy state method. We show that a longer distance QKD is possible by utilizing a heralded single photon source (utilizing spontaneous parametric down-conversion) as a source instead of a weak coherent pulse (WCP) as proposed in the original decoy state method. Moreover, the key rate is improved by utilizing a presently available photon number resolving detector as a trigger detector of the heralded single photon source and it is shown to approach the key rate of the WCP.
Multiple flat photonic bands with finite Chern numbers
NASA Astrophysics Data System (ADS)
Chui, S. T.; Liu, Shiyang; Lin, Zhifang
2013-09-01
We show both analytically and numerically that there is an infinite number of flat bands with different Chern numbers in a two-dimensional magnetic photonic crystal at nearly the same frequency determined by the condition that the effective magnetic permeability ?eff?-1. This opens the door to explore the physics involving higher order topological invariants in this system. The frequency of these states can be flexibly tuned by an external magnetic field.
Multiple flat photonic bands with finite Chern numbers.
Chui, S T; Liu, Shiyang; Lin, Zhifang
2013-09-01
We show both analytically and numerically that there is an infinite number of flat bands with different Chern numbers in a two-dimensional magnetic photonic crystal at nearly the same frequency determined by the condition that the effective magnetic permeability ?_{eff}?-1. This opens the door to explore the physics involving higher order topological invariants in this system. The frequency of these states can be flexibly tuned by an external magnetic field. PMID:24125207
Fermi-Dirac statistics and the number theory
Anna Kubasiak; Jaroslaw K. Korbicz; Jakub Zakrzewski; Maciej Lewenstein
2005-01-01
We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap to partitions of given integers into distinct parts, studied in number theory. Using methods of quantum statistical physics we derive analytic expressions for cumulants of the probability distribution of the number of different partitions.
Fermi-Dirac statistics and the number theory
A. Kubasiak; J. Korbicz; J. Zakrzewski; M. Lewenstein
2005-07-27
We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap to partitions of given integers into distinct parts, studied in number theory. Using methods of quantum statistical physics we derive analytic expressions for cumulants of the probability distribution of the number of different partitions.
Apollo by the Numbers: A Statistical Reference
NASA Technical Reports Server (NTRS)
Orloff, Richard; Garber, Stephen (Technical Monitor)
2000-01-01
The purpose of this work is to provide researchers, students, and space enthusiasts with a comprehensive reference for facts about Project Apollo, America's effort to put humans in the Moon. Research for this work started in 1988, when the author discovered that, despite the number of excellent books that focused on the drama of events that highlighted Apollo, there were none that focused on the drama of the numbers. This book is separated into two parts. The first part contains narratives for the Apollo 1 fire and the 11 flown Apollo missions. Included after each narrative is a series of data tables, followed by a comprehensive timeline of events from just before liftoff to just after crew and spacecraft recovery. The second part contains more than 50 tables. These tables organize much of the data from the narratives in one place so they can be compared among all missions. The tables offer additional data as well. The reader can select a specific mission narrative or specific data table by consulting the Table of Contents.
The numbers game: evaluation of statistics by obstetrics & gynecology.
Pitkin, Roy M; Scott, James R; Burmeister, Leon F
2014-02-01
Statistical analysis has become integral to the planning, conduct, and reporting of modern medical research. Attention to the statistical aspects of manuscripts submitted to Obstetrics & Gynecology goes back approximately 40 years and the process used in their evaluation has evolved over that time. For the past 20 years, submissions with any type of statistics and being seriously considered for acceptance have routinely been reviewed by a Statistical Editor who judges the work on a number of statistical and design characteristics. Findings of the statistical design review (which has been done by one Statistical Editor over the entire 20-year period) are integrated into the editorial decision about acceptance. The statistical review generally leads to rejection of approximately 16-25% of manuscripts and in a larger proportion, it identifies less serious problems, the correction of which improves the final product. PMID:24402593
Photon-number-resolving decoy-state quantum key distribution
Qing-Yu Cai; Yong-Gang Tan
2006-01-01
In this paper, a photon-number-resolving decoy-state quantum key distribution (QKD) scheme is presented based on recent experimental advancements. A new upper bound on the fraction of counts caused by multiphoton pulses is given, which seems inherent as long as weak coherent sources and high lossy channel are used. This implies that our scheme is optimal in long-distance QKD with weak
Nonclassical imaging via photon-number fluctuation correlation
Jane N. Sprigg; Tao Peng; Yanhua Shih
2014-10-23
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.
Manipulation of photon statistics of highly degenerate chaotic radiation
M. Kindermann; Yu. V. Nazarov; C. W. J. Beenakker
2001-07-05
Highly degenerate chaotic radiation has a Gaussian density matrix and a large occupation number of modes $f $. If it is passed through a weakly transmitting barrier, its counting statistics is close to Poissonian. We show that a second identical barrier, in series with the first, drastically modifies the statistics. The variance of the photocount is increased above the mean by a factor $f$ times a numerical coefficient. The photocount distribution reaches a limiting form with a Gaussian body and highly asymmetric tails. These are general consequences of the combination of weak transmission and multiple scattering.
Gerrits, Thomas; Lita, Adriana E.; Calkins, Brice; Tomlin, Nathan A.; Fox, Anna E.; Linares, Antia Lamas; Mirin, Richard P.; Nam, Sae Woo [National Institute of Standards and Technology, Boulder, Colorado, 80305 (United States); Thomas-Peter, Nicholas; Metcalf, Benjamin J.; Spring, Justin B.; Langford, Nathan K.; Walmsley, Ian A. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Gates, James C.; Smith, Peter G. R. [Optoelectronics Research Centre, University of Southampton, Highfield SO17 1BJ (United Kingdom)
2011-12-15
Integration is currently the only feasible route toward scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2{+-}0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.
Chrapkiewicz, Rados?aw
2015-01-01
Photon number resolving detectors can be highly useful for studying the statistics of multi-photon quantum states of light. In this work we study the counts statistics of different states of light measured on multiplexed on-off detectors. We put special emphasis on artificial nonclassical features of the statistics obtained. We show new ways to derive analytical formulas for counts statistics and their moments. Using our approach we are the first to derive statistics moments for multi-mode thermal states measured on multiplexed on-off detectors. We use them to determine empirical Mandel parameters and recently proposed subbinomial parameters suitable for tests of nonclassicality of the measured states. Additionally, we investigate subpoissonian and superbunching properties of the two-mode squeezed state measured on a pair of multiplexed detectors and we present results of the Fano factor and second-order correlation function for these states.
Observation of squeezed states with 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
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.
Predicting landfalling hurricane numbers from basin hurricane numbers: basic statistical analysis
Laepple, T; Penzer, J; Bellone, E; Nzerem, K; Laepple, Thomas; Jewson, Stephen; Penzer, Jeremy; Bellone, Enrica; Nzerem, Kechi
2007-01-01
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.
NASA Technical Reports Server (NTRS)
Platnick, S.
1999-01-01
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.
Near-IR photon number resolving detector design
NASA Astrophysics Data System (ADS)
Bogdanski, Jan; Huntington, Elanor H.
2013-05-01
Photon-Number-Resolving-Detection (PNRD) capability is crucial for many Quantum-Information (QI) applications, e.g. for Coherent-State-Quantum-Computing, Linear-Optics-Quantum-Computing. In Quantum-Key-Distribution and Quantum-Secret-Sharing over 1310/1550 nm fiber, two other important, defense and information security related, QI applications, it's crucial for the information transmission security to guarantee that the information carriers (photons) are single. Thus a PNRD can provide an additional security level against eavesdropping. Currently, there are at least a couple of promising PNRD technologies in the Near-Infrared, but all of them require cryogenic cooling. Thus a compact, portable PNRD, based on commercial Avalanche-Photo-Diodes (APDs), could be a very useful instrument for many QI experiments. For an APD-based PNRD, it is crucial to measure the APD-current in the beginning of the avalanche. Thus an efficient cancellation of the APD capacitive spikes is a necessary condition for the very weak APD current measurement. The detector's principle is based on two commercial, pair-matched InGaAs/InP APDs, connected in series. It leads to a great cancelation of the capacitive spikes caused by the narrow (300 ps), differential gate-pulses of maximum 4V amplitude assuming that both pulses are perfectly matched in regards to their phases, amplitudes, and shapes. The cancellation scheme could be used for other APD-technologies, e.g. Silicon, extending the detection spectrum from visible to NIR. The design distinguishes itself from other, APD-based, schemes by its scalability feature and its computer controlled cancellation of the capacitive spikes. Furthermore, both APDs could be equally used for the detection purpose, which opens a possibility for the odd-even photon number parity detection.
A brief history of numbers and statistics with cytometric applications.
Watson, J V
2001-02-15
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
Generation of Photon Number States on Demand via Cavity Quantum Electrodynamics
Simon Brattke; Benjamin T. Varcoe; Herbert Walther
2001-01-01
Many applications in quantum information or quantum computing require radiation with a fixed number of photons. This increased the demand for systems able to produce such fields. We discuss the production of photon fields with a fixed photon number on demand. The first experimental demonstration of the device is described. This setup is based on a cavity quantum electrodynamics scheme
Elementary Business Statistics Unique Number 04360, 04365, 04370
Ghosh, Joydeep
STA309 Elementary Business Statistics Unique Number 04360, 04365, 04370 PROFESSOR Dr. Greenberg.306 E-mail: Betsy.Greenberg@utexas.edu TEACHING ASSISTANTS Prana Narayana Xiao Han Email: prana.n88Pal, a credit card, or an Access Code that may have been included with your textbook purchase. In addition
REVSTAT Statistical Journal Volume 8, Number 1, June 2010, 3755
Alves, Maria Isabel Fraga
pollutants like ozone, carbon monoxide or sulfur dioxide constitute time series that can be analyzed underREVSTAT Â Statistical Journal Volume 8, Number 1, June 2010, 37Â55 OPTIMAL ALARM SYSTEMS.pereira@ua.pt Received: June 2009 Revised: March 2010 Accepted: March 2010 Abstract: Â· In this work, an optimal alarm
Photon statistics of coherent harmonic radiation of a linac free electron laser
Teng Chen
1999-01-01
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
Spin-statistics-quantum number connection and supersymmetry
Richard M. Weiner
2013-02-05
The analogy between the Skyrme and Higgs field leads to the conjecture that all fermions are skyrmions and thus always carry conserved quantum numbers, which are identified with baryon or lepton quantum numbers. This connection between spin and quantum numbers, which parallels the connection between spin and statistics due to the Pauli principle, may explain why supersymmetry has not been observed. Creation of s-particles at higher than present energies due to a breakdown of the Skyrme mechanism might imply the violation of the exclusion principle.
Mukamel, Shaul
Photon statistics of intense entangled photon pulses This article has been downloaded from statistics of intense entangled photon pulses Frank Schlawin and Shaul Mukamel Department of Chemistry, University of California, Irvine, CA 92697-2025, USA E-mail: Frank.Schlawin@physik
Statistical fluctuations of transmission in slow light photonic-crystal waveguides
Paris-Sud XI, UniversitÃ© de
slow-wave delay lines," Opt. Express 15(25), 17273Â17282 (2007). 7. T. Baba, "Slow light in photonic identical and that only differ because of statistical structural fabrication-induced imperfections
Cooperative effects in photon statistics of molecular dimers with spectral diffusion
Mukamel, Shaul
properties of coupled molecules in organic crystals,1Â3 photosynthetic antennae4Â6 and J aggregates7 haveCooperative effects in photon statistics of molecular dimers with spectral diffusion Frantisek effort has focused on analyzing the autocorrelation function g 2 and the factorial moments of photon
AN AUTOMATED STATISTICAL ANALYSIS APPROACH TO NOISE REDUCTION FOR PHOTON-COUNTING LIDAR SYSTEMS
Kerekes, John
AN AUTOMATED STATISTICAL ANALYSIS APPROACH TO NOISE REDUCTION FOR PHOTON-COUNTING LIDAR SYSTEMS K, Rochester, NY, USA ABSTRACT Satellite-based and airborne lidar instrumentation has been demonstrated the Multiple Altimeter Beam Experimental Lidar (MABEL) instrument, an experimental photon-counting lidar
Statistical issues in the analysis of DNA Copy Number Variations
Wineinger, Nathan E.; Kennedy, Richard E.; Erickson, Stephen W.; Wojczynski, Mary K.; Bruder, Carl E.
2009-01-01
Approaches to assess copy number variation have advanced rapidly and are being incorporated into genetic studies. While the technology exists for CNV genotyping, a further understanding and discussion of how to use the CNV data for association analyses is warranted. We present the options available for processing and analysing CNV data. We break these steps down into choice of genotyping platform, normalisation of the array data, calling algorithm, and statistical analysis. PMID:19774103
Puentes, G; Feito, A; Eisert, J; Plenio, M B; Walmsley, I A
2009-01-01
The certificate of success for a number of important quantum information processing protocols, such as entanglement distillation, is based on the difference in the entanglement content of the quantum states before and after the protocol. In such cases, effective bounds need to be placed on the entanglement of non-local states consistent with statistics obtained from local measurements. In this work, we study numerically the ability of a novel type of homodyne detector which combines phase sensitivity and photon-number resolution to set accurate bounds on the entanglement content of two-mode quadrature squeezed states without the need for full state tomography. We show that it is possible to set tight lower bounds on the entanglement of a family of two-mode degaussified states using only a few measurements. This presents a significant improvement over the resource requirements for the experimental demonstration of continuous-variable entanglement distillation, which traditionally relies on full quantum state t...
G. Puentes; A. Datta; A. Feito; J. Eisert; M. B. Plenio; I. A. Walmsley
2009-11-12
The certificate of success for a number of important quantum information processing protocols, such as entanglement distillation, is based on the difference in the entanglement content of the quantum states before and after the protocol. In such cases, effective bounds need to be placed on the entanglement of non-local states consistent with statistics obtained from local measurements. In this work, we study numerically the ability of a novel type of homodyne detector which combines phase sensitivity and photon-number resolution to set accurate bounds on the entanglement content of two-mode quadrature squeezed states without the need for full state tomography. We show that it is possible to set tight lower bounds on the entanglement of a family of two-mode degaussified states using only a few measurements. This presents a significant improvement over the resource requirements for the experimental demonstration of continuous-variable entanglement distillation, which traditionally relies on full quantum state tomography.
Three-Pulse Photon Echo of Finite Numbers of Molecules: Single-Molecule Traces
Fleming, Graham R.
of single-molecule photon echo or equivalent types of measurements. In particular, the three-pulse photonThree-Pulse Photon Echo of Finite Numbers of Molecules: Single- Molecule Traces Hui Dong and Graham, 6227]. To avoid this drawback of ensemble measurements and evaluate single-molecule behavior, a quantum
Statistical Detection and Imaging of Objects Hidden in Turbid Media Using Ballistic Photons
Eriksson, Brian
Statistical Detection and Imaging of Objects Hidden in Turbid Media Using Ballistic Photons Sina pixel statistical tests for detecting objects hidden in turbid media. To improve the detection rate. Introduction High resolution imaging and detection of objects hidden in a turbid (scattering) medium have long
Statistical detection and imaging of objects hidden in turbid media using ballistic photons
Statistical detection and imaging of objects hidden in turbid media using ballistic photons Sina-pixel statistical tests for detecting objects hidden in turbid media. To improve the detection rate High-resolution imaging and detection of objects hid- den in a turbid (scattering) medium have long
G. P. Berman; A. A. Chumak
2007-02-26
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.
Advanced Photon Source research: Volume 1, Number 1, April 1998
NONE
1998-04-01
The following articles are included in this publication: (1) The Advanced Photon Source: A Brief Overview; (2) MAD Analysis of FHIT at the Structural Biology Center; (3) Advances in High-Energy-Resolution X-ray Scattering at Beamline 3-ID; (4) X-ray Imaging and Microspectroscopy of the Mycorrhyizal Fungus-Plant Symbiosis; (5) Measurement and Control of Particle-beam Trajectories in the Advanced Photon Storage Ring; (6) Beam Acceleration and Storage at the Advanced Photon Source; and (7) Experimental Facilities Operations and Current Status.
A Study of Optimal Mean Photon Number Analysis in Quantum Key Distribution (QKD)
L. I. A. Ghazali; W. A. W. Adnan; M. Mokhtar; A. F. Abas; M. A. Mahdi
2008-01-01
This paper presents a study of optimal mean photon number (mu) analysis in quantum key distribution (QKD) experiments. The rationale of this study is to analyze the eavesdropping technology assumptions regarding the optimal mean photon number. This work limits its scope only on the fiber-based QKD implementation.
Statistical distributions of earthquake numbers: consequence of branching process
NASA Astrophysics Data System (ADS)
Kagan, Yan Y.
2010-03-01
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.
Absolute efficiency estimation of photon-number-resolving detectors using twin beams
Worsley, A P; Lundeen, J S; Mosley, P J; Smith, B J; Puentes, G; Thomas-Peter, N; Walmsley, I A; 10.1364/OE.17.004397
2009-01-01
A nonclassical light source is used to demonstrate experimentally the absolute efficiency calibration of a photon-number-resolving detector. The photon-pair detector calibration method developed by Klyshko for single-photon detectors is generalized to take advantage of the higher dynamic range and additional information provided by photon-number-resolving detectors. This enables the use of brighter twin-beam sources including amplified pulse pumped sources, which increases the relevant signal and provides measurement redundancy, making the calibration more robust.
Absolute efficiency estimation of photon-number-resolving detectors using twin beams.
Worsley, A P; Coldenstrodt-Ronge, H B; Lundeen, J S; Mosley, P J; Smith, B J; Puentes, G; Thomas-Peter, N; Walmsley, I A
2009-03-16
A nonclassical light source is used to demonstrate experimentally the absolute efficiency calibration of a photon-number-resolving detector. The photon-pair detector calibration method developed by Klyshko for single-photon detectors is generalized to take advantage of the higher dynamic range and additional information provided by photon-number-resolving detectors. This enables the use of brighter twin-beam sources including amplified pulse pumped sources, which increases the relevant signal and provides measurement redundancy, making the calibration more robust. PMID:19293867
Effective Atomic Numbers of Lanthanides with Gamma Radiation for Photon Energy Absorption
NASA Astrophysics Data System (ADS)
Shantappa, Anil; Hanagodimath, S. M.
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.
Absolute efficiency estimation of photon-number-resolving detectors using twin beams
A. P. Worsley; H. B. Coldenstrodt-Ronge; J. S. Lundeen; P. J. Mosley; B. J. Smith; G. Puentes; N. Thomas-Peter; I. A. Walmsley
2009-06-11
A nonclassical light source is used to demonstrate experimentally the absolute efficiency calibration of a photon-number-resolving detector. The photon-pair detector calibration method developed by Klyshko for single-photon detectors is generalized to take advantage of the higher dynamic range and additional information provided by photon-number-resolving detectors. This enables the use of brighter twin-beam sources including amplified pulse pumped sources, which increases the relevant signal and provides measurement redundancy, making the calibration more robust.
Multi-bit quantum random number generation by measuring positions of arrival photons.
Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun
2014-10-01
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
Multi-bit quantum random number generation by measuring positions of arrival photons
Yan, Qiurong, E-mail: yanqiurong@ncu.edu.cn [Department of Electronics Information Engineering, Nanchang University, Nanchang 330031 (China); State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119 (China); Zhao, Baosheng [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119 (China); Liao, Qinghong; Zhou, Nanrun [Department of Electronics Information Engineering, Nanchang University, Nanchang 330031 (China)
2014-10-15
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.
Multi-bit quantum random number generation by measuring positions of arrival photons
NASA Astrophysics Data System (ADS)
Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun
2014-10-01
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.
Photon statistics of resonance fluorescence in the limit of separated spectral lines.
Arnoldus, Henk F; Battaglia, Franco; George, Thomas F
2014-08-21
We have studied the statistics of fluorescent photons emitted by a two-state atom in a laser beam in the limit where either the detuning or the Rabi frequency is large. For this case, the spectrum of resonance fluorescence has three separated lines. We have obtained closed form expressions for the conditional probability density for the emission of the nth photon and for the probability for emission of n photons in a time interval [0,T]. Our solutions are complementary to the known solutions for the case of perfect resonance. PMID:24689746
Photon-number fluctuation and correlation of bound soliton pairs in mode-locked fiber lasers
Ray-Kuang Lee; Yinchieh Lai; Boris A. Malomed
2005-06-14
Quantum photon-number fluctuation and correlation of bound soliton pairs in mode-locked fiber lasers are studied based on the complex Ginzburg-Landau equation model. We find that, depending on their phase difference, the total photon-number noise of the bound soliton pair can be larger or smaller than that of a single soliton and the two solitons in the soliton pairs are with positive or negative photon-number correlation, correspondingly. It is predicted for the first time that out-of-phase soliton pairs can exhibit less noises due to negative correlation.
Lischinski, Dani
Photon Maps Photon Tracing Simulating light propagation by shooting photons from the light sources. Photon Tracing Storing the incidences of photon's path. Implementing surface properties statistically. Russian Roulette. Photon Tracing Photon maps keep: Incidence point (in 3D). The normal at that point
Proposal for a superconducting photon number resolving detector with large dynamic range.
Jahanmirinejad, Saeedeh; Fiore, Andrea
2012-02-27
We propose a novel photon number resolving detector structure with large dynamic range. It consists of the series connection of N superconducting nanowires, each connected in parallel to an integrated resistor. Photon absorption in a wire switches its current to the parallel resistor producing a voltage pulse and the sum of these voltages is measured at the output. The combination of this structure and a high input impedance preamplifier result in linear, high fidelity, and fast photon detection in the range from one to several tens of photons. PMID:22418306
Statistics for Geography Teachers: Topics in Geography, Number 2.
ERIC Educational Resources Information Center
National Council for Geographic Education.
This publication is designed to provide geography teachers with useful statistical information. It presents tables, maps, graphs, diagrams, and explanations of statistical data in 24 areas. The areas in which statistics are given are conversions, measurement, astronomy, time, daylight, twilight, latitude and longitude as distance, the relationship…
Beating the Abbe Diffraction Limit in Confocal Microscopy via Nonclassical Photon Statistics
NASA Astrophysics Data System (ADS)
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
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.
Beating the Abbe diffraction limit in confocal microscopy via nonclassical photon statistics.
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
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
Higher order antibunching and subpossonian photon statistics in five wave mixing process
Amit Verma; Anirban Pathak
2009-09-03
We have investigated the possibility of observing higher order antibunching (HOA) and higher order subpossonian photon statistics (HOSPS) in five wave mixing and third harmonic generation process. It had been shown that both processes satisfy the criteria of HOA and HOSPS. Further, some observations on the nature of interaction which produces HOA and HOSPS are reported.
Adaptive Quantum Nondemolition Measurement of a Photon Number
NASA Astrophysics Data System (ADS)
Peaudecerf, B.; Rybarczyk, T.; Gerlich, S.; Gleyzes, S.; Raimond, J. M.; Haroche, S.; Dotsenko, I.; Brune, M.
2014-02-01
In many quantum measurements, information is acquired incrementally by the successive interaction of meters with the measured system. Adaptive measurements minimize the use of resources (meters) by adjusting the measurement settings according to available information. We demonstrate an adaptive measurement for nondestructive photon counting in a cavity, based on Ramsey interferometry for Rydberg atoms interacting with the field. Tuning the interferometer in real time, we speed up the measurement by up to 45%. Such adaptive methods are promising for quantum metrology, state preparation, and feedback.
Lin Song [State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of Mathematics and Computer Science, Fujian Normal University, Fuzhou 350007 (China); Wen Qiaoyan; Gao Fei [State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Zhu Fuchen [National Laboratory for Modern Communications, P.O. Box 810, Chengdu 610041 (China)
2009-05-15
A collective photon-number-splitting attack strategy is proposed, which combines photon-number-splitting attack with an unambiguous set discrimination of quantum state. Verified by this attack strategy, it is shown that a two-way quantum secure direct communication protocol with qubits is insecure in real circumstance. Finally, we present a possible improved version of this kind of quantum secure direct communication protocol.
SUBMILLIMETER NUMBER COUNTS FROM STATISTICAL ANALYSIS OF BLAST MAPS
Patanchon, Guillaume [Universite Paris Diderot, Laboratoire APC, 10, rue Alice Domon et Leonie Duquet 75205 Paris (France); Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Moncelsi, Lorenzo; Pascale, Enzo [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Bock, James J. [School of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff, CF24 3AA (United Kingdom); Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas [Jet Propulsion Laboratory, Pasadena, CA 91109-8099 (United States); Devlin, Mark J.; Dicker, Simon R.; Klein, Jeff; Rex, Marie [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Gundersen, Joshua O. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Hughes, David H. [Instituto Nacional de AstrofIsica Optica y Electronica (INAOE), Aptdo. Postal 51 y 72000 Puebla (Mexico); Netterfield, Calvin B. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street Toronto, ON M5S 3H4 (Canada); Olmi, Luca, E-mail: patanchon@apc.univ-paris-diderot.f [Physics Department, University of Puerto Rico, Rio Piedras Campus, P.O. Box 23343, UPR Station, San Juan (Puerto Rico)
2009-12-20
We describe the application of a statistical method to estimate submillimeter galaxy number counts from confusion-limited observations by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called 'P(D)', an approach which has been used before to probe faint counts, the difference being that here we advocate its use even for sources with relatively high signal-to-noise ratios. This method has an advantage over standard techniques of source extraction in providing an unbiased estimate of the counts from the bright end down to flux densities well below the confusion limit. We specifically analyze BLAST observations of a roughly 10 deg{sup 2} map centered on the Great Observatories Origins Deep Survey South field. We provide estimates of number counts at the three BLAST wavelengths 250, 350, and 500 mum; instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with power laws. We observe a generally very steep slope for the counts of about -3.7 at 250 mum, and -4.5 at 350 and 500 mum, over the range approx0.02-0.5 Jy, breaking to a shallower slope below about 0.015 Jy at all three wavelengths. We also describe how to estimate the uncertainties and correlations in this method so that the results can be used for model-fitting. This method should be well suited for analysis of data from the Herschel satellite.
Paris-Sud XI, Université de
Experimental determination of the statistics of photons emitted by a tunnel junction Eva Zakka'Etat Condens´e/IRAMIS/DSM (CNRS URA 2464), CEA Saclay, F-91191 Gif-sur-Yvette, France (Dated: January 9, 2010) We report on a microwave Hanbury-Brown Twiss experiment probing the statistics of GHz photons emitted
REVSTAT Statistical Journal Volume 10, Number 1, March 2012, 135165
Alves, Maria Isabel Fraga
Statistical and Applied Mathematical Sciences Institute, Research Triangle Park, NC, USA (sunwards extreme air pollution events presents unique statistical challenges, and requires one to characterize, temperature, or air pollution are measured at specifically-located mon- itors, spatial modeling is necessary
Unified single-photon and single-electron counting statistics: from cavity-QED to electron transport
Neill Lambert; Yueh-Nan Chen; Franco Nori
2010-08-26
A key ingredient of cavity quantum-electrodynamics (QED) is the coupling between the discrete energy levels of an atom and photons in a single-mode cavity. The addition of periodic ultra-short 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' non-equilibrium model. We then show that there is a one-to-one correspondence of this model to that of non-equilibrium transport of electrons through a double quantum dot nanostructure. Then we prove that the statistics of the tunnelling electrons is equivalent to the statistics of the emitted photons. This represents a unification of 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.
Sub-shot-noise photon-number correlation in a mesoscopic twin beam of light
Bondani, Maria [National Laboratory for Ultrafast and Ultraintense Optical Science, C.N.R.-I.N.F.M., Como (Italy); Allevi, Alessia; Andreoni, Alessandra [C.N.R.-I.N.F.M.-C.N.I.S.M., Dipartimento di Fisica e Matematica, Universita dell'Insubria, Como (Italy); Zambra, Guido [Dipartimento di Fisica e Matematica, Universita dell'Insubria, Como (Italy); Dipartimento di Fisica dell'Universita di Milano, Milan (Italy); Paris, Matteo G. A. [Dipartimento di Fisica dell'Universita di Milano, Milan (Italy)
2007-07-15
We demonstrate sub-shot-noise photon-number correlations in a (temporal) multimode mesoscopic ({approx}10{sup 3} detected photons) twin beam produced by picosecond-pulsed spontaneous nondegenerate parametric down-conversion. We have separately detected the signal and idler distributions of photons collected in twin coherence areas and found that the variance of the photon-count difference goes below the shot-noise limit by 3.25 dB. The number of temporal modes contained in the twin beam, as well as the size of the twin coherence areas, depends on the pump intensity. Our scheme is based on spontaneous down-conversion and thus does not suffer from limitations due to the finite gain of the parametric process. Twin beams are also used to demonstrate the conditional preparation of a nonclassical (sub-Poissonian) state.
Crunching Numbers: What Cancer Screening Statistics Really Tell Us
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.
Volume 114. number 4 CHEMICAL PHYSICS LETTERS 8 March I985 UNIFIED THEORY OF PHOTON ECHOES
Mukamel, Shaul
Volume 114. number 4 CHEMICAL PHYSICS LETTERS 8 March I985 UNIFIED THEORY OF PHOTON ECHOESIon of non-mtcractmg two-lcvcl s)`stems. whose frequcnclcs undergo Gauss~n random modulntlons The model Publishers B.V. (North-Holland Physics Publishing Division) #12;Volume 114, number 4 CHEMICAL PHYSICS LETTERS
Su-Yong Lee; Se-Wan Ji; Hai-Woong Lee; Jae-Weon Lee; János A. Bergou
2009-01-01
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.
Absolute calibration of photon-number-resolving detectors with an analog output using twin beams
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
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.
Statistical x-ray computed tomography imaging from photon-starved measurements
NASA Astrophysics Data System (ADS)
Chang, Zhiqian; Zhang, Ruoqiao; Thibault, Jean-Baptiste; Sauer, Ken; Bouman, Charles
2013-03-01
Dose reduction in clinical X-ray computed tomography (CT) causes low signal-to-noise ratio (SNR) in photonsparse situations. Statistical iterative reconstruction algorithms have the advantage of retaining image quality while reducing input dosage, but they meet their limits of practicality when significant portions of the sinogram near photon starvation. The corruption of electronic noise leads to measured photon counts taking on negative values, posing a problem for the log() operation in preprocessing of data. In this paper, we propose two categories of projection correction methods: an adaptive denoising filter and Bayesian inference. The denoising filter is easy to implement and preserves local statistics, but it introduces correlation between channels and may affect image resolution. Bayesian inference is a point-wise estimation based on measurements and prior information. Both approaches help improve diagnostic image quality at dramatically reduced dosage.
Photon statistics in a free-electron laser with an axial-guide magnetic field
NASA Astrophysics Data System (ADS)
San-Kui, Gou
1992-07-01
Starting from an initial state with an electron energy p20/2m+??c/2, a vacuum-laser field, and a coherent wiggler field, I discuss photon statistics in a free-electron laser with an axial-guide magnetic field. It is found that the axial field can weaken the squeezing, enhance the positive (for ?>0) and negative (for ?<0) gain, and strengthen the bunching (for ?>0) and antibunching (for ?<0).
Pulse pileup statistics for energy discriminating photon counting x-ray detectors
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
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.
Canadian Statistical Review. Volume 53, Number 7, July 1978.
ERIC Educational Resources Information Center
von Zur-Muehlen, Max
1978-01-01
Information on Canadian social and economic trends is presented in this statistical review. Advance information on national income and expenditure accounts for the first quarter of 1978 is provided. Characteristics of full-time university teachers from 1956-57 to 1977-78 are detailed in tables that recount such developments as the nearly six-fold…
USA by Numbers: A Statistical Portrait of the United States.
ERIC Educational Resources Information Center
Weber, Susan, Ed.
This book presents demographic data about a variety of U.S. public policies, social problems, and environmental issues. The issues and problems that the statistics illustrate (such as overflowing garbage dumps, homelessness, child poverty, and smog and water pollution) are connected with, and the consequences of, the expanding U.S. population. The…
Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion
Gupta, Subhadeep; Moore, Kevin L.; Murch, Kater W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Stamper-Kurn, Dan M. [Department of Physics, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2007-11-23
We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to 10{sup 5} {sup 87}Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allows for strongly nonlinear optics at extremely low cavity photon numbers, as demonstrated by the observation of both branches of optical bistability at photon numbers below unity.
Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion
Subhadeep Gupta; Kevin L. Moore; Kater W. Murch; Dan M. Stamper-Kurn
2007-09-05
We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to $10^5$ $^{87}$Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allows for strongly nonlinear optics at extremely low cavity photon numbers, as demonstrated by the observation of both branches of optical bistability at photon numbers below unity.
Set partition statistics and q-Fibonacci numbers
Adam M. Goyt; Bruce E. Sagan
2009-01-01
We consider the set partition statistics ls and r b introduced by Wachs and White and investigate their distribution over set partitions that avoid certain patterns. In particular, we consider those set partitions avoiding the pattern 13=2, n.13=2\\/, and those avoiding both 13=2 and 123, n.13=2; 123\\/. We show that the distribution over n.13=2\\/ enumerates certain integer partitions, and the
The Statistics of the Number of Neutron Collisions Prior to Absorption
PÃ¡zsit, Imre
The Statistics of the Number of Neutron Collisions Prior to Absorption Sara A. Pozzi* Oak Ridge Accepted July 25, 2005 Abstract Â 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
Waterman, Michael S.
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
Which is the most suitable number of photon beam portals in coplanar radiation therapy?
Svante Söderström; Anders Brahme
1995-01-01
Computer-controlled milling machines for compensator manufacture, dynamic multileaf collimators, and narrow scanned electron or bremsstrahlung photon beams have opened up new possibilities to shape nonuniform fluence profiles and have thus, paved the road for truly three dimensional (3D) dose delivery. The present paper investigates the number of beam portals required to optimize coplanar radiation therapy using uniform and nonuniform dose
Photon-number superselection and the entangled coherent-state representation
Sanders, Barry C.; Bartlett, Stephen D.; Rudolph, Terry; Knight, Peter L. [Department of Physics, Macquarie University, Sydney, New South Wales 2109 (Australia); Bell Laboratories, 600-700 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Optics Section, Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom)
2003-10-01
We introduce the entangled coherent-state representation, which provides a powerful technique for efficiently and elegantly describing and analyzing quantum optics sources and detectors while respecting the photon-number superselection rule that is satisfied by all known quantum optics experiments. We apply the entangled coherent-state representation to elucidate and resolve the long-standing puzzles of the coherence of a laser output field, interference between two number states, and dichotomous interpretations of quantum teleportation of coherent states.
Set partition statistics and qFibonacci numbers Adam M. Goyt #
Sagan, Bruce
Set partition statistics and qÂFibonacci numbers Adam M. Goyt # Department of Mathematics Michigan certain integer partitions, and the distribution over # n (13/2, 123) gives qÂFibonacci numbers. These qÂFibonacci numbers are closely related to qÂFibonacci numbers studied by Carlitz and by Cigler. We provide
Bingjie Xu; Xiang Peng; Hong Guo
2010-10-08
A passive scheme with a beam splitter and a photon-number-resolving (PNR) detector is proposed to verify the photon statistics of an untrusted source in a plug-and-play quantum-key-distribution system by applying a three-intensity decoy-state protocol. The practical issues due to statistical fluctuation and detection noise are analyzed. The simulation results show that the scheme can work efficiently when the total number of optical pulses sent from Alice to Bob is above 10^8, and the dark count rate of the PNR detector is below 0.5 counts/pulse, which is realizable with current techniques. Furthermore, we propose a practical realization of the PNR detector with a variable optical attenuator combined with a threshold detector.
Scholz, Matthias; Koch, Lars; Benson, Oliver
2009-02-13
Narrow-band single photons represent an important resource for quantum memories due to their efficient interaction with atomic resonances. In this Letter, we report on the generation of photons with 3 MHz linewidth by cavity-enhanced parametric down-conversion and demonstrate direct proof of their single-photon character by detection of heralding idler photons. Compared to a Poissonian source, a suppression of higher-order photon numbers by nearly 2 orders of magnitude could be achieved. Moreover, the brightness of our source exceeds previous realizations by more than a factor of 100. PMID:19257589
NASA Astrophysics Data System (ADS)
Lee, Su-Yong; Ji, Se-Wan; Lee, Hai-Woong; Lee, Jae-Weon; Bergou, János A.
2009-09-01
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.
NASA Astrophysics Data System (ADS)
Shivaramu,; Vijayakumar, R.; Rajasekaran, L.; Ramamurthy, N.
2001-12-01
Effective atomic numbers for photon energy absorption (Z PEAeff) and effective atomic numbers for photon interaction (Z PIeff) of some low- Z substances of dosimetric interest such as A-150 tissue-equivalent plastic (A150TEP), alanine, bakelite, Gafchromic sensor (GS), plastic scintillator (PS), polyethylene, mylar, polystyrene, perspex, radiochromic dye film nylon base (RDF : NB), tissue-equivalent gas-methane based (TEG : MB) and tissue-equivalent gas-propane based (TEG : PB) have been calculated by a direct method in the energy region of 1 keV-20 MeV. Experimental mass attenuation coefficients and Z PIeff of some of these substances at selected photon energies of 26.34, 33.2, and 59.54 keV have been obtained and compared with theoretical values. The Z PEAeff and Z PIeff values steadily increases up to 6-15 keV, and then they steadily decrease up to 600-1500 keV for all the substances studied. From 1.5 MeV, the values increases with increase in energy up to 20 MeV. Significant differences up to 33.68% exist between Z PIeff and the Z PEAeff in the energy region of 10-150 keV. The single effective atomic numbers obtained using the program XMuDat (Z XMUDATeff ) are found to be significantly higher compared to those of Z PEAeff and Z PIeff values in the entire energy of interest for all the substances studied. The directly calculated Z PEAeff and Z PIeff values vary with energy compared to the energy-independent effective atomic numbers predicted by various theoretical expressions. The effects of absorption edges on effective atomic numbers and their variation with photon energy and the possibility of defining two set values of effective atomic numbers below the absorption edges of elements present in the composite substances are discussed.
NASA Astrophysics Data System (ADS)
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
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.
Statistical Handbook on Aging Americans. 1994 Edition. Statistical Handbook Series Number 5.
ERIC Educational Resources Information Center
Schick, Frank L., Ed.; Schick, Renee, Ed.
This statistical handbook contains 378 tables and charts illustrating the changes in the United States' aging population based on data collected during the 1990 census and several other surveys. The tables and charts are organized by topic as follows: demographics (age and sex distribution, life expectancy, race and ethnicity, geographic…
Photon statistics and speckle visibility spectroscopy with partially coherent X-rays.
Li, Luxi; Kwa?niewski, Pawe?; Orsi, Davide; Wiegart, Lutz; Cristofolini, Luigi; Caronna, Chiara; Fluerasu, Andrei
2014-11-01
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
Comparing Data Sets: Implicit Summaries of the Statistical Properties of Number Sets
ERIC Educational Resources Information Center
Morris, Bradley J.; Masnick, Amy M.
2015-01-01
Comparing datasets, that is, sets of numbers in context, is a critical skill in higher order cognition. Although much is known about how people compare single numbers, little is known about how number sets are represented and compared. We investigated how subjects compared datasets that varied in their statistical properties, including ratio of…
Photon number resolution enables quantum receiver for realistic coherent optical communications
NASA Astrophysics Data System (ADS)
Becerra, F. E.; Fan, J.; Migdall, A.
2015-01-01
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.
Generic Two-Photon (Two-Qubit) Gates Implemented by Number-Resolving Photodetection
Dmitry Uskov
2010-01-01
Existing theoretical results on measurement-induced two-qubit photonic gates with number-resolving photodetection [1] are limited to only the controlled-NOT gate (Knill et al Nature 409, 46-52 (2001)). We use numerical optimization techniques (Uskov et al PRA 79, 042326 (2009)), to find optimal schemes implementing arbitrary two-qubit entangling gates, represented by generic points in the Weyl chamber of Cartan KAK decomposition of
True random number generator based on discretized encoding of the time interval between photons.
Li, Shen; Wang, Long; Wu, Ling-An; Ma, Hai-Qiang; Zhai, Guang-Jie
2013-01-01
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
Zhai, Yanhua, E-mail: yanhuazhai@gmail.com, E-mail: jfan@nist.gov; Fan, Jingyun, E-mail: yanhuazhai@gmail.com, E-mail: jfan@nist.gov; Migdall, Alan [Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, 100 Bureau Drive, Mail Stop 8441, Gaithersburg, Maryland 20899 (United States); Becerra, Francisco E. [Center for Quantum Information and Control, MSC07-4220, University of New Mexico, Albuquerque, New Mexico 87131 (United States)
2014-09-08
We examine thermal light diffracted through a double slit using photon-number-resolved detection to directly measure high-order spatial correlations, and we see sinusoidal modulations of those correlations. The fringe width can, in principal, be made arbitrarily small, and we have experimentally obtained fringe widths as small as 30?nm with 800?nm wavelength light. This extreme sub-wavelength resolution, along with this direct detection technique, offers potential for high precision measurement applications.
Photon-number entangled states generated in Kerr media with optical parametric pumping
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
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.
Photon-number entangled states generated in Kerr media with optical parametric pumping
Anna Kowalewska-Kud?aszyk; Wies?aw Leo?ski; Jan Pe?ina Jr
2011-04-26
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.
Photon-number entangled states generated in Kerr media with optical parametric pumping
Kowalewska-Kud?aszyk, Anna; Pe?ina, Jan
2011-01-01
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.
Measuring photon-photon interactions via photon detection
Mihai A. Macovei
2010-06-18
The strong non-linearity plays a significant role in physics, particularly, in designing novel quantum sources of light and matter as well as in quantum chemistry or quantum biology. In simple systems, the photon-photon interaction can be determined analytically. However, it becomes challenging to obtain it for more compex systems. Therefore, we show here how to measure strong non-linearities via allowing the sample to interact with a weakly pumped quantized leaking optical mode. We found that the detected mean-photon number versus pump-field frequency shows several peaks. Interestingly, the interval between neighbour peaks equals the photon-photon interaction potential. Furthermore, the system exhibits sub-Poissonian photon statistics, entanglement and photon switching with less than one photon. Finally, we connect our study with existing related experiments.
Dynamics of dispersive photon-number QND measurements in a micromaser
Kozlovskii, A. V. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)], E-mail: kozlovsk@sci.lebedev.ru
2007-04-15
A numerical analysis of dispersive quantum nondemolition measurement of the photon number of a microwave cavity field is presented. Simulations show that a key property of the dispersive atom-field interaction used in Ramsey interferometry is the extremely high sensitivity of the dynamics of atomic and field states to basic parameters of the system. When a monokinetic atomic beam is sent through a microwave cavity, a qualitative change in the field state can be caused by an uncontrollably small deviation of parameters (such as atom path length through the cavity, atom velocity, cavity mode frequency detuning, or atom-field coupling constants). The resulting cavity field can be either in a Fock state or in a super-Poissonian state (characterized by a large photon-number variance). When the atoms have a random velocity spread, the field is squeezed to a Fock state for arbitrary values of the system's parameters. However, this makes detection of Ramsey fringes impossible, because the probability of detecting an atom in the upper or lower electronic state becomes a random quantity almost uniformly distributed over the interval between zero and unity, irrespective of the cavity photon number.
Attacks exploiting deviation of mean photon number in quantum key distribution and coin tossing
Shihan Sajeed; Igor Radchenko; Sarah Kaiser; Jean-Philippe Bourgoin; Anna Pappa; Laurent Monat; Matthieu Legre; Vadim Makarov
2015-03-30
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.
Unified position-dependent photon-number quantization in layered structures
Mikko Partanen; Teppo Häyrynen; Jani Oksanen; Jukka Tulkki
2014-12-01
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.
Unified position-dependent photon-number quantization in layered structures
NASA Astrophysics Data System (ADS)
Partanen, Mikko; Häyrynen, Teppo; Oksanen, Jani; Tulkki, Jukka
2014-12-01
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.
NASA Technical Reports Server (NTRS)
Richardson, W. H.; Yamamoto, Y.
1991-01-01
The photon-number fluctuation of the external field from a semiconductor laser - which was reduced to below the standard quantum limit - is shown to be correlated with the measured junction-voltage noise. The spectral density of the sum of the photon-number fluctuation and junction-voltage fluctuation falls below the squeezed photon-number fluctuation. This confirms the theoretical predictions that this correlation, which originates in the dipole interaction between the internal field and electron-hole pairs, extends into the quantum regime.
Strong field line shapes and photon statistics from a single molecule under anomalous noise
NASA Astrophysics Data System (ADS)
Šanda, František
2009-10-01
We revisit the line-shape theory of a single molecule with anomalous stochastic spectral diffusion. Waiting time profiles for bath induced spectral jumps in the ground and excited states become different when a molecule, probed by continuous-wave laser field, reaches the steady state. This effect is studied for the stationary dichotomic continuous-time-random-walk spectral diffusion of a single two-level chromophore with power-law distributions of waiting times. Correlated waiting time distributions, line shapes, two-point fluorescence correlation function, and Mandel Q parameter are calculated for arbitrary magnitude of laser field. We extended previous weak field results and examined the breakdown of the central limit theorem in photon statistics, indicated by asymptotic power-law growth of Mandel Q parameter. Frequency profile of the Mandel Q parameter identifies the peaks of spectrum, which are related to anomalous spectral diffusion dynamics.
On the Spectrum of Field Quadratures for a Finite Number of Photons
Emilio Pisanty; Eduardo Nahmad-Achar
2012-09-04
The spectrum and eigenstates of any field quadrature operator restricted to a finite number $N$ of photons are studied, in terms of the Hermite polynomials. By (naturally) defining \\textit{approximate} eigenstates, which represent highly localized wavefunctions with up to $N$ photons, one can arrive at an appropriate notion of limit for the spectrum of the quadrature as $N$ goes to infinity, in the sense that the limit coincides with the spectrum of the infinite-dimensional quadrature operator. In particular, this notion allows the spectra of truncated phase operators to tend to the complete unit circle, as one would expect. A regular structure for the zeros of the Christoffel-Darboux kernel is also shown.
Higher Order Squeezing and Higher Order Subpoissonian Photon Statistics in Intermediate States
Amit Verma; Anirban Pathak
2010-04-10
Recently simpler criteria for the Hong-Mandel higher order squeezing (HOS) and higher order subpossonian photon statistics (HOSPS) are provided by us [Phys. Lett. A 374 (2010) 1009]. Here we have used these simplified criteria to study the possibilities of observing HOSPS and HOS in different intermediate states, such as generalized binomial state, hypergeometric state, negative binomial state and photon added coherent state. It is shown that these states may satisfy the condition of HOS and HOSPS. It is also shown that the depth and region of nonclassicality can be controlled by controlling various parameters related to intermediate states. Further, we have analyzed the mutual relationship between different signatures of higher order nonclassicality with reference to these intermediate states. We have observed that the generalized binomial state may show signature of HOSPS in absence of HOS. Earlier we have shown that NLVSS shows HOS in absence of HOSPS. Consequently it is established that the HOSPS and HOS of same order are independent phenomenon.
NASA Astrophysics Data System (ADS)
Maghrebi, Mohammad F.; Jaffe, Robert L.; Kardar, Mehran
2014-07-01
We study the implications of quantum fluctuations of a dispersive medium, under steady rotation, either in or out of thermal equilibrium with its environment. A rotating object exhibits a quantum instability by dissipating its mechanical motion via spontaneous emission of photons, as well as internal heat generation. Universal relations are derived for the radiated energy and angular momentum as trace formulas involving the object's scattering matrix. We also compute the quantum noise by deriving the full statistics of the radiated photons out of thermal and/or dynamic equilibrium. The (entanglement) entropy generation is quantified and the total entropy is shown to be always increasing. Furthermore, we derive a Fokker-Planck equation governing the stochastic angular motion resulting from the fluctuating backreaction frictional torque. As a result, we find a quantum limit on the uncertainty of the object's angular velocity in steady rotation. Finally, we show in some detail that a rotating object drags nearby objects, making them spin parallel to its axis of rotation. A scalar toy model is introduced to simplify the technicalities and ease the conceptual complexities and then a detailed discussion of quantum electrodynamics is presented.
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
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.
Binter, R; Khare, S; Binter, Roman; Jewson, Stephen; Khare, Shree
2007-01-01
We are building a hurricane number prediction scheme that relies, in part, on statistical modelling of the empirical relationship between Atlantic sea surface temperatures and Atlantic basin hurricane numbers. We test out a number of simple statistical models for this relationship, using data from 1900 to 2005 and data from 1950 to 2005, and for both all hurricane numbers and intense hurricane numbers.
Discrimination of Optical Coherent States using a Photon Number Resolving Detector
Christoffer Wittmann; Ulrik L. Andersen; Gerd Leuchs
2009-07-14
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.
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
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.
Performance of Number-Between g Type Statistical Control Charts for Monitoring Adverse Events
James C. Benneyan
2001-01-01
Alternate Shewhart-type statistical control charts, called “g” and “h” charts, have been developed for monitoring the number of cases between hospital-acquired infections and other adverse events, such as heart surgery complications, catheter-related infections, surgical site infections, contaminated needle sticks, medication errors and other care induced concerns. This article investigates the statistical properties of these new charts and illustrates several design
Kobayashi, M; Inaba, H
2000-01-01
Ultraweak photon emission phenomena in the visible to near-IR region, originating from biological organisms, are known. This biophoton emission is generated during metabolic processes and constitutes physiological information. We investigated a technique for characterizing the optical radiation field based on photon statistics and correlation analysis to extract information on regulation processes in biochemical reactions and their interactions. We developed the system based on the time-interval measurement of photoelectrons in a photon-counting region and employed data processing with a nonstationary optical field with correction for the correlative properties of the photomultiplier dark current. We analyzed biophoton emission from cellular slime mold (Dictyosterium discoideum) and observed the characteristic variation of this organism's super-Poisson statistics during the developmental process. PMID:18337887
Statistical Power to Detect the Correct Number of Classes in Latent Profile Analysis
Coxe, Stefany; Cham, Heining
2012-01-01
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
I. Dohan; T. Gemesy; T. Sandor; A. Somogyi
1958-01-01
In a Wilson cloud chamber with an effective cross section of 300 cm\\/sup ; 2\\/, seven lead plates of 33 mm thickness were placed. The chamber was regulated ; by an apparatus for extensive air showers, and the numbers of primary electrons ; and electron pairs were counted. After a correction for the number of ; penetrating photons, the ratio
Wolfram Birmili; Alfred Wiedensohler; Jost Heintzenberg; Katrin Lehmann
2001-01-01
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
Statistical Structure at the Wall of the High Reynolds Number Turbulent Boundary Layer
J. C. R. HUNT; P. CARLOTTI
2001-01-01
The one and two-point statistical structure of very high Reynolds number turbulence in the surface layer near a rigid 'wall' is analysed. The essential mechanisms for turbulent eddies impinging on the wall are studied using linearised rapid distortion theory, which show how the mean shear and blocking actions of the surface act first independently and then, over the life time
Binter, R; Khare, S; Binter, Roman; Jewson, Stephen; Khare, Shree
2007-01-01
We are building a hurricane number prediction scheme that relies, in part, on statistical modelling of the empirical relationship between Atlantic sea surface temperatures and landfalling hurricane numbers. We test out a number of simple statistical models for that relationship, using data from 1900 to 2005 and data from 1950 to 2005, and for both all hurricane numbers and intense hurricane numbers. The results are very different from the corresponding analysis for basin hurricane numbers.
Higher-order photon statistics of single-mode laser diodes and microchip solid-state lasers
NASA Astrophysics Data System (ADS)
Lim, Tsong-Shin; Chern, Jyh-Long; Otsuka, Kenju
2002-12-01
We examine higher-order photon statisitics of laser diodes (LDs) and microchip solid-state lasers (SSLs). When the lasers are operated above lasing threshold, significantly different features of fluctuations are exhibited, which are the result of the asymmetric non-Gaussian distribution characteristics that are always present in SSLs, whereas, in contrast, Gaussian fluctuation persists in LDs. It is found that the deterministic dynamic trajectory in phase space, which is controlled by the ratio between the fluorescence and the photon lifetimes, is crucial to the corresponding behavior of higher-order statistics.
Statistical independence of a new class of inversive congruential pseudorandom numbers
Eichenauer-Herrmann, J.
1993-01-01
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.
Wideband direction finding using a photonic robust symmetrical number system technique
NASA Astrophysics Data System (ADS)
Tedesso, Thomas W.; Calusdian, James; Sewing, Carsten; Pace, Phillip E.
2014-11-01
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.
Statistical properties of online avatar numbers in a massive multiplayer online role-playing game
NASA Astrophysics Data System (ADS)
Jiang, Zhi-Qiang; Ren, Fei; Gu, Gao-Feng; Tan, Qun-Zhao; Zhou, Wei-Xing
2010-02-01
Massive multiplayer online role-playing games (MMORPGs) have been very popular in the past few years. The profit of an MMORPG company is proportional to how many users registered, and the instant number of online avatars is a key factor to assess how popular an MMORPG is. We use the online-offline logs on an MMORPG server to reconstruct the instant number of online avatars per second and investigate its statistical properties. We find that the online avatar number exhibits one-day periodic behavior and clear intraday pattern, the fluctuation distribution of the online avatar numbers has a leptokurtic non-Gaussian shape with power-law tails, and the increments of online avatar numbers after removing the intraday pattern are uncorrelated and the associated absolute values have long-term correlation. In addition, both time series exhibit multifractal nature.
Statistical Structure at the Wall of the High Reynolds Number Turbulent Boundary Layer
J. C. R. Hunt; P. Carlotti
2001-01-01
The one and two-point statistical structure of very high Reynolds number turbulence in the surface layer near a rigid `wall'\\u000a is analysed. The essential mechanisms for turbulent eddies impinging on the wall are studied using linearised rapid distortion\\u000a theory, which show how the mean shear and blocking actions of the surface act first independently and then, over the life\\u000a time
D'Ariano, Giacomo Mauro
with a novel self-homodyne technique. These distributions exhibit the thermal-state character predicted The procedure of direct sampling is greatly simplified if one is interested only in the photon- number, can be utilized at the NOPA output as a matched LO for the detection of squeezed vacuum generated
D. Savran; S. Müller; A. Zilges; M. Babilon; M. W. Ahmed; J. H. Kelley; A. Tonchev; W. Tornow; H. R. Weller; N. Pietralla; J. Li; I. V. Pinayev; Y. K. Wu
2005-01-11
The 100 % polarized photon beam at the High Intensity gamma-ray Source (HIgS) at Duke University has been used to determine the parity of six dipole excitations between 2.9 and 3.6 MeV in the deformed nuclei 172,174 Yb in photon scattering (g,g') experiments. The measured parities are compared with previous assignments based on the K quantum number that had been assigned in Nuclear Resonance Fluorescence (NRF) experiments by using the Alaga rules. A systematic survey of the relation between gamma-decay branching ratios and parity quantum numbers is given for the rare earth nuclei.
Photon Number-Phase Uncertainty Relation in the Evolution of the Field in a Kerr-Like Medium
NASA Technical Reports Server (NTRS)
Fan, An-Fu; Sun, Nian-Chun
1996-01-01
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.
Quantum Fingerprinting with Coherent States and a Constant Mean Number of Photons
Juan Miguel Arrazola; Norbert Lütkenhaus
2014-06-17
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.
NSDL National Science Digital Library
2012-08-03
In this activity using an open space and a thick rope, students simulate the movement of photons from the Sun. The resource is part of the teacher's guide accompanying the video, NASA Why Files: The Case of the Mysterious Red Light. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.
One-point statistics for turbulent wall-bounded flows at Reynolds numbers up to ?+ ? 2000
NASA Astrophysics Data System (ADS)
Sillero, Juan A.; Jiménez, Javier; Moser, Robert D.
2013-10-01
One-point statistics are presented for new direct simulations of the zero-pressure-gradient turbulent boundary layer in the range Re? = 2780-6680, matching channels and pipes at ?+ ? 1000-2000. For tripped boundary layers, it is found that the eddy-turnover length is a better criterion than the Reynolds number for the recovery of the largest flow scales after an artificial inflow. Beyond that limit, the integral parameters, mean velocities, Reynolds stresses, and pressure fluctuations of the new simulations agree very well with the available numerical and experimental data, but show clear differences with internal flows when expressed in wall units at the same wall distance and Reynolds number. Those differences are largest in the outer layer, independent of the Reynolds number, and apply to the three velocity components. The logarithmic increase with the Reynolds number of the maximum of the streamwise velocity and pressure fluctuations is confirmed to apply to experimental and numerical internal and external flows. The new simulations also extend to a wider range of Reynolds numbers, and to more than a decade in wall distance, the evidence for logarithmic intensity profiles of the spanwise velocity and of the pressure intensities. Streamwise velocity fluctuations appear to require higher Reynolds numbers to develop a clear logarithmic profile, but it is argued that the comparison of the available near-wall data with fluctuation profiles experimentally obtained by other groups at higher Reynolds numbers can only be explained by assuming the existence of a mesolayer for the fluctuations. The statistics of the new simulation are available in our website.
Which is the most suitable number of photon beam portals in coplanar radiation therapy?
Soederstroem, S.; Brahme, A. [Univ. of Stockholm (Sweden)] [Univ. of Stockholm (Sweden)
1995-08-30
Computer-controlled milling machines for compensator manufacture, dynamic multileaf collimators, and narrow scanned electron or bremsstrahlung photon beams have opened up new possibilities to shape nonuniform fluence profiles and have thus, paved the road for truly three dimensional (3D) dose delivery. The present paper investigates the number of beam portals required to optimize coplanar radiation therapy using uniform and nonuniform dose delivery. Nonuniform dose delivery allows a considerable improvement in the treatment outcome compared to uniform dose delivery. The results also show a close relationship between the dose distribution parameters and the probability of achieving complication-free tumor control. To achieve optimal expectation value of the treatment outcome, within an accuracy of a few percent as measured by the probability of achieving complication-free tumor control, it is generally sufficient to use three nonuniform beam portals. A very large number of coplanar beams may only raise the probability of achieving complication-free tumor control by 1 to 2%. However, good treatment outcome with three beam portals requires that the directions of incidence of the coplanar nonuniform beams are optimally selected. If, on the other hand, the treatment is performed using uniform beams, it is not possible, even with an infinite number of fields, to obtain as high a level of complication-free tumor control as with a few nonuniform beams. From an optimization point of view, it is sufficient to reach a relative standard deviation of the mean dose to the target volume of around 3%. Improved dose homogeneity beyond this level will, in general, not significantly improve the complication-free tumor control. 20 refs., 5 figs., 2 tabs.
Statistical Study on Personal Reduction Coefficients of Sunspot Numbers Since 1981
NASA Astrophysics Data System (ADS)
Cho, Il-Hyun; Bong, Su-Chan; Cho, Kyung-Suk; Lee, Jaejin; Kim, Rok-Soon; Park, Young-Deuk; Kim, Yeon-Han
2014-12-01
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.
Yuriy Hlushchuk; Stefanie Russ
2003-07-29
We study the level statistics (second half moment $I_0$ and rigidity $\\Delta_3$) and the eigenfunctions of pseudointegrable systems with rough boundaries of different genus numbers $g$. We find that the levels form energy intervals with a characteristic behavior of the level statistics and the eigenfunctions in each interval. At low enough energies, the boundary roughness is not resolved and accordingly, the eigenfunctions are quite regular functions and the level statistics shows Poisson-like behavior. At higher energies, the level statistics of most systems moves from Poisson-like towards Wigner-like behavior with increasing $g$. Investigating the wavefunctions, we find many chaotic functions that can be described as a random superposition of regular wavefunctions. The amplitude distribution $P(\\psi)$ of these chaotic functions was found to be Gaussian with the typical value of the localization volume $V_{\\rm{loc}}\\approx 0.33$. For systems with periodic boundaries we find several additional energy regimes, where $I_0$ is relatively close to the Poisson-limit. In these regimes, the eigenfunctions are either regular or localized functions, where $P(\\psi)$ is close to the distribution of a sine or cosine function in the first case and strongly peaked in the second case. Also an interesting intermediate case between chaotic and localized eigenfunctions appears.
NASA Astrophysics Data System (ADS)
Bechera, I. R.; Meda, A.; Degiovanni, I.; Brida, G.; Genovese, M.
2014-10-01
In this proceeding we discuss as quantum correlations can enhance measurements capabilities [1,2,3,6], discussing few examples as target detection in a noisy environment and holometer. The first [2] is a quantum enhanced scheme preserving a strong advantage over classical counterparts even in presence of large amount of noise and losses. Our work, inspired by [3], has been performed exploiting only photon number correlations in twin beams. Thus, for its simplicity it can find widespread use. Even more important by challenging the common believe that real application of quantum technologies is limited by fragility to noise and losses, it paves the way to their real application. Then, we describe as the same kind of correlations can find application in a completely different area of physics, i.e. in testing quantum gravity. Indeed, recently, effects in interferometers connected to noncommutativity of position variables in different directions were considered in two coupled interferometers [5], the ``holometer'' [6]. We show that the use of quantum correlated light beams could lead to significant improvements.
Mean velocity statistics and turbulent structure in a very high Reynolds number boundary layer
NASA Astrophysics Data System (ADS)
Morris, Scott
2005-11-01
PIV measurements were acquired over a region of y+ up to 3000 in the atmospheric surface layer at the SLTEST site with a range of 6000 wall units in the streamwise direction. The surface roughness was k+=14, with a boundary layer thickness of order 100m. The thermal conditions were neutral for more than one hour prior to and after the measurement period. A total of 708 snapshots were acquired in a 25 minute period where the wind conditions were nearly stationary. In this talk, mean velocity statistics will be used in comparison to the log-law fit as well as a power law fit. RMS statistics and Reynolds stresses will be compared with lower Reynolds number data. Finally, the structure of the flow will be described both in terms of stochastic quantities, such as the two point correlation functions, as well as instantaneous visualizations of the vector field.
Light statistics by non-calibrated linear photodetectors
Maria Bondani; Alessia Allevi; Alessandra Andreoni
2008-10-22
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.
NASA Astrophysics Data System (ADS)
Grazioso, Fabio; Grosshans, Frédéric
2013-11-01
We propose a family of sifting-less quantum-key-distribution protocols which use reverse reconciliation, and are based on weak coherent pulses (WCPs) polarized along m different directions. When m=4, the physical part of the protocol is identical to most experimental implementations of BB84 [Bennett and Brassard, in Proceedings of the IEEE International Conference on Computers, Systems, and Signal Processing (IEEE, New York, 1984)] and SARG04 [Scarani, Acín, Ribordy, and Gisin, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.92.057901 92, 057901 (2004); Acín, Gisin, and Scarani, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.69.012309 69, 012309 (2004)] protocols and they differ only in classical communications and data processing. We compute their total key rate as a function of the channel transmission T, using general information theoretical arguments, and we show that they have a higher key rate than the more standard protocols, both for fixed and optimized average photon number of the WCPs. When no decoy-state protocols (DSPs) [Hwang, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.91.057901 91, 057901 (2003); Lo, Ma, and Chen, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.94.230504 94, 230504 (2005); Wang, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.72.012322 72, 012322 (2005)] are applied, the scaling of the key rate with transmission is improved from T2 for BB84 to T1+(1)/(m-2). If a DSP is applied, we show how the key rates scale linearly with T, with an improvement of the prefactor by 75.96% for m=4. High values of m allow one to asymptotically approach the key rate obtained with ideal single-photon pulses. The fact that the key rates of these sifting-less protocols are higher compared to those of the aforementioned more standard protocols show that the latter are not optimal, since they do not extract all the available secret keys from the experimental correlations.
Statistics of the cosmic Mach number from numerical simulations of a cold dark matter universe
NASA Technical Reports Server (NTRS)
Suto, Yasushi; Cen, Renyue; Ostriker, Jeremiah P.
1992-01-01
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.
Burke, D.L.
1982-10-01
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.
Cavity resonances dominating the photon statistics in the non-equilibrium steady state
Felix Rüting; Christoph Weiss
2014-05-28
The non-equilibrium-steady state (NEST) for photons in a cavity is investigated theoretically. The NEST is caused by different parts of the cavity being at distinct temperatures or by temperature gradients. By using a rate equation based on the Lindblad equation, we derive an analytic expression for the steady-state distribution of the photon spectrum. We predict differences between the non-equilibrium steady state and a fit to the black-body spectrum calculated via Planck's law with an effective temperature. For two bodies of similar size at two temperatures which differ by a factor of two, the difference would be more than 10%. We also show that cavity resonances have a particularly large influence on the resulting non-equilibrium steady state of the photons. The investigation of thermal spectra in the presence of more than one temperature can be important for high-precision atomic clocks.
Photon Counting Statistics of Thermal Light Consisting of Two Spectral Lines
N. Tornau; B. Echtermeyer
1973-01-01
The generating function for the photon counting distribution is calculated for polarized thermal light in the case that the spectral profile of the light is a superposition of two LORENTZian lines with the same central frequency but different halfwidth at half height. Further we present results for the moments of the counting distribution in this case and also for a
NASA Astrophysics Data System (ADS)
Takeda, Mitsuo; Wang, Wei; Naik, Dinesh N.
2011-10-01
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.
Discovery and statistical genotyping of copy-number variation from whole-exome sequencing depth.
Fromer, Menachem; Moran, Jennifer L; Chambert, Kimberly; Banks, Eric; Bergen, Sarah E; Ruderfer, Douglas M; Handsaker, Robert E; McCarroll, Steven A; O'Donovan, Michael C; Owen, Michael J; Kirov, George; Sullivan, Patrick F; Hultman, Christina M; Sklar, Pamela; Purcell, Shaun M
2012-10-01
Sequencing of gene-coding regions (the exome) is increasingly used for studying human disease, for which copy-number variants (CNVs) are a critical genetic component. However, detecting copy number from exome sequencing is challenging because of the noncontiguous nature of the captured exons. This is compounded by the complex relationship between read depth and copy number; this results from biases in targeted genomic hybridization, sequence factors such as GC content, and batching of samples during collection and sequencing. We present a statistical tool (exome hidden Markov model [XHMM]) that uses principal-component analysis (PCA) to normalize exome read depth and a hidden Markov model (HMM) to discover exon-resolution CNV and genotype variation across samples. We evaluate performance on 90 schizophrenia trios and 1,017 case-control samples. XHMM detects a median of two rare (<1%) CNVs per individual (one deletion and one duplication) and has 79% sensitivity to similarly rare CNVs overlapping three or more exons discovered with microarrays. With sensitivity similar to state-of-the-art methods, XHMM achieves higher specificity by assigning quality metrics to the CNV calls to filter out bad ones, as well as to statistically genotype the discovered CNV in all individuals, yielding a trio call set with Mendelian-inheritance properties highly consistent with expectation. We also show that XHMM breakpoint quality scores enable researchers to explicitly search for novel classes of structural variation. For example, we apply XHMM to extract those CNVs that are highly likely to disrupt (delete or duplicate) only a portion of a gene. PMID:23040492
Javadi, Alisa; Maibom, Sebastian; Sapienza, Luca; Thyrrestrup, Henri; García, Pedro D; Lodahl, Peter
2014-12-15
We present a statistical study of the Purcell enhancement of the light emission from quantum dots coupled to Anderson-localized cavities formed in disordered photonic-crystal waveguides. We measure the time-resolved light emission from both single quantum emitters coupled to Anderson-localized cavities and directly from the cavities that are fed by multiple quantum dots. Strongly inhibited and enhanced decay rates are observed relative to the rate of spontaneous emission in a homogeneous medium. From a statistical analysis, we report an average Purcell factor of 4.5 ± 0.4 without applying any spectral tuning. By spectrally tuning individual quantum dots into resonance with Anderson-localized modes, a maximum Purcell factor of 23.8 ± 1.5 is recorded, which is at the onset of the strong-coupling regime. Our data quantify the potential of Anderson-localized cavities for controlling and enhancing the light-matter interaction strength in a photonic-crystal waveguide, which is of relevance for cavity quantum-electrodynamics experiments, efficient energy harvesting and random lasing. PMID:25607048
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
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.
Full counting statistics for the number of electrons in a quantum dot
NASA Astrophysics Data System (ADS)
Utsumi, Yasuhiro
2007-01-01
Motivated by recent real-time electron counting experiments, we evaluate the full counting statistics for the probability distribution of the electron number inside a quantum dot which is weakly coupled to source and drain leads. A non-Gaussian exponential distribution appears when there is no dot state close to the lead chemical potentials. We propose the measurement of the joint probability distribution of current and electron number, which reveals correlations between the two observables. We also show that for increasing strength of tunneling, the quantum fluctuations qualitatively change the probability distribution of the electron number. In this paper, we derive the cumulant generating functions (CGFs) of the joint probability distribution for several cases. The Keldysh generating functional approach is adopted to obtain the CGFs for the resonant-level model and for the single-electron transistor in the intermediate conductance regime. The general form for the CGF of the joint probability distribution is provided within the Markov approximation in an extension of the master equation approach [D. A. Bagrets and Yu. V. Nazarov, Phys. Rev. B 67, 085316 (2003)].
Higher-order photon correlations in pulsed photonic crystal nanolasers
Elvira, D.; Hachair, X.; Braive, R.; Beaudoin, G.; Robert-Philip, I.; Sagnes, I.; Abram, I.; Beveratos, A. [Laboratoire de Photonique et Nanostructures LPN-CNRS UPR20, Route de Nozay, F-91460 Marcoussis (France); Verma, V. B.; Baek, B.; Nam, S. W.; Stevens, M. J. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305 (United States); Dauler, E. A. [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)
2011-12-15
We report on the higher-order photon correlations of a high-{beta} nanolaser under pulsed excitation at room temperature. Using a multiplexed four-element superconducting single-photon detector we measured g{sup (n)}(0-vector) with n=2,3,4. All orders of correlation display partially chaotic statistics, even at four times the threshold excitation power. We show that this departure from coherence and Poisson statistics is due to the quantum fluctuations associated with the small number of photons at the lasing threshold.
Resolution and sensitivity of a Fabry-Perot interferometer with a photon-number-resolving detector
Dowling, Jonathan P.
compared to a classical detection strategy. We also theoretically show supersensitivity if N-photon states with coherent light are one of the building blocks for high-precision metrology. Recent progress in the field of different quantum-light sources in interferometric schemes 1Â3 . One such detector 4 , the transition edge
A Supplement to "The Number of Guttman Errors as a Simple and Powerful Person-Fit Statistic."
ERIC Educational Resources Information Center
Meijer, Rob R.
1995-01-01
A statistic used by R. Meijer (1994) to determine person-fit referred to the number of errors from the deterministic Guttman model (L. Guttman, 1950), but this was, in fact, based on the number of errors from the deterministic Guttman model as defined by J. Loevinger (1947, 1948). (SLD)
Solar light trapping in slanted conical-pore photonic crystals: Beyond statistical ray trapping
John, Sajeev
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
NASA Astrophysics Data System (ADS)
Liu, Xiang-Yuan; Qian, Xian-Mei; Li, Yu-Jie; Rao, Rui-Zhong
2014-12-01
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.
Zalialiutdinov, T; Labzowsky, L; Plunien, G
2014-01-01
We establish the existence of spin-statistic selection rules (SSSR) for multi-equal-photon transitions in atomic systems. These selection rules are similar to those for systems of many equivalent electrons in atomic theory. The latter ones are the direct consequence of Pauli exclusion principle. In this sense the SSSR play the role of the exclusion principle for photons: they forbid some particular states for the photon systems. We established several SSSR for few-photon systems. 1) First rule (SSSR-1): two-equivalent photons involved in any atomic transition can have only even values of the total angular momentum J. This selection rule is an extension of the Landau-Yang theorem to the photons involved in atomic transitions. 2) second rule (SSSR-2): three equivalent dipole photons involved in any atomic transition can have only odd values of the total angular momentum J=1,3. 3) third rule (SSSR-3): four equivalent dipole photons involved in any atomic transition can have only even values of the total angular ...
NASA Astrophysics Data System (ADS)
Bhattacharjee, A.; Sinha, A. K.
1988-07-01
Albedo measurements for backscattered gamma rays from semi-infinite scatterers have suitable applications in the design of gamma ray shields particularly in nuclear reactor and accelerator shields and in many other nuclear installations. The insertion of lead slabs into stratified combination with other shielding materials has been found to increase the shielding property appreciably. The stratified slabs of alternating heterogeneous layers have been found in this investigation to have a virtual homogeneous property with a definite effective atomic number. The purpose of the present investigation is to find out the extent to which the shielding property increases in binary configuration with lead and to investigate into the dependence of the saturation thickness of the shielding media on the effective atomic number of each configuration. The indigeneously designed Uniform Sensitivity Photon Counter used in this investigation has an edge over all previous methods of experimental measurements that it is independent of response correction. The number albedo values as well as angular distribution of backscattered photons for iron, aluminium and concrete stratified with lead slabs at 662 keV energy have been reported here.
Armand Niederberger; Valerio Scarani; Nicolas Gisin
2005-04-15
In practical quantum cryptography, the source sometimes produces multi-photon pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Lutkenhaus [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.
Yu, Alex
/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
Generic Two-Qubit Photonic Gates Implemented by Number-Resolving Photodetection
Dmitry B. Uskov; A. Matthew Smith; Lev Kaplan
2009-10-01
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.
R. Descartes; G.-C. Rota; L. Euler; J. D. Bernoulli; Edward Carl-Ludwig Siegel
2011-01-01
Quantum-statistics Dichotomy: Fermi-Dirac(FDQS) Versus Bose-Einstein(BEQS), respectively with contact-repulsion\\/non-condensation(FDCR) versus attraction\\/ condensationBEC are manifestly-demonstrated by Taylor-expansion ONLY of their denominator exponential, identified BOTH as Descartes analytic-geometry conic-sections, FDQS as Elllipse (homotopy to rectangle FDQS distribution-function), VIA Maxwell-Boltzmann classical-statistics(MBCS ) to Parabola MORPHISM, VS. BEQS to Hyperbola, Archimedes' HYPERBOLICITY INEVITABILITY, and as well generating-functions[Abramowitz-Stegun, Handbook Math.-Functions--p. 804!!!], respectively of Euler-numbers\\/functions, (via Riemann
NASA Astrophysics Data System (ADS)
Javadi, Alisa; Maibom, Sebastian; Sapienza, Luca; Thyrrestrup, Henri; García, Pedro D.; Lodahl, Peter
2014-12-01
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.
Low-latency photonic packet switches with large number of ports
S. Di Lucente; N. Calabretta; H. J. S. Dorren
2011-01-01
We investigate optical switching architectures that can scale to thousands of input\\/output ports, in the context of link latency and packet loss. We present an architecture that is capable to scale to large number of nodes while introducing low latency. I. INTRODUCTION The overall performance of High Performance Computers (HPCs) and Data Centers (DCs) enters the petaflop\\/sec era (1), thus
Fayer, Michael D.
Volume175.number3 CHEMICALPHYSICSLETTERS 7December1990 Thermal history and temperature thermal history. The word glass does not have as specific a definition as the term crystal does. When thinking of a crystal, one imagines a solid composed of atoms and/or molecules packed in a highly ordered
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
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.
Direct Observation of Sub-Poissonian Number Statistics in a Degenerate Bose Gas
C. -S. Chuu; F. Schreck; T. P. Meyrath; J. L. Hanssen; G. N. Price; M. G. Raizen
2005-12-21
We report the direct observation of sub-Poissonian number fluctuation for a degenerate Bose gas confined in an optical trap. Reduction of number fluctuations below the Poissonian limit is observed for average numbers that range from 300 to 60 atoms.
Static Numbers to Dynamic Statistics: Designing a Policy-Friendly Social Policy Indicator Framework
ERIC Educational Resources Information Center
Ahn, Sang-Hoon; Choi, Young Jun; Kim, Young-Mi
2012-01-01
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.…
Manufacturing Numbers: How Inaccurate Statistics Conceal U.S. Industrial Decline.
ERIC Educational Resources Information Center
Mishel, Lawrence
Contrary to a major statistical series calculated by the U.S. Bureau of Economic Analysis, the Gross Product Originating (GPO) series, the United States has experienced a definite erosion of its industrial base between 1973 and 1985, with manufacturing dropping at least 2.8 percent and perhaps as much as 4.5 percent in its share of national…
Equipartitions and a Distribution for Numbers: A Statistical Model for Benford's Law
Iafrate, Joseph R; Strauch, Frederick W
2015-01-01
A statistical model for the fragmentation of a conserved quantity is analyzed, using the principle of maximum entropy and the theory of partitions. Upper and lower bounds for the restricted partitioning problem are derived and applied to the distribution of fragments. The resulting power law directly leads to Benford's law for the first digits of the parts.
ERIC Educational Resources Information Center
Trupin, Laura; Rice, Dorothy P.; Max, Wendy
This statistical abstract presents data on the sources of payment for medical care for people with disabilities in different age groups. All estimates come from the National Medical Expenditures Survey, a nationally representative survey of the civilian non-institutionalized population of the U.S. conducted in 1987. Six categories of payment…
Financial Statistics, 1980-81. Our Colleges and Universities Today. Volume XIX, Number 8.
ERIC Educational Resources Information Center
Hottinger, Gerald W.
Financial statistics for Pennsylvania colleges and universities for the fiscal year (FY) ending 1981, for 1971-1972 through 1980-1981, and for 1977-1978 through 1980-1981 are presented, along with narrative descriptions of financial trends at the institutions. Information includes the following: current-funds revenues by institutional control;…
Statistical Estimation of Some Irrational Numbers Using an Extension of Buffon's Needle Experiment
ERIC Educational Resources Information Center
Velasco, S.; Roman, F. L.; Gonzalez, A.; White, J. A.
2006-01-01
In the nineteenth century many people tried to seek a value for the most famous irrational number, [pi], by means of an experiment known as Buffon's needle, consisting of throwing randomly a needle onto a surface ruled with straight parallel lines. Here we propose to extend this experiment in order to evaluate other irrational numbers, such as…
Turbulence statistics in fully developed channel flow at low Reynolds number
John Kim; Parviz Moin; Robert Moser
1987-01-01
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
Statistical Tests of the Apple IIe Random Number Generator Yield Suggestions from Generator Seeding.
ERIC Educational Resources Information Center
Gleason, John M.
1988-01-01
Discusses flaws in the Apple IIe Applesoft random number generator, RND, and reports results of frequency and serial correlation tests of the generator. Suggestions of seeds that yield sequences of numbers which pass fundamental screening tests for randomness are presented. (Author/LRW)
Ismail, S I M F
2015-01-01
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
On the Poisson Approximation to Photon Distribution for Faint Lasers Yucheng Hua
Lu, Tiao
On the Poisson Approximation to Photon Distribution for Faint Lasers Yucheng Hua , Xiang Pengb statistics for attenuated faint laser pulses is quantitatively studied. It confirms that, even for a non-Poissonian laser source, after being attenuated into faint laser with ultra-low mean photon number, the photon
NSDL National Science Digital Library
2013-06-14
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.
Statistical Estimation of the Gasoline Octane Number Requirement of New Model Automobiles
Claude S. Brinegar; Ronald R. Miller
1960-01-01
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.
NSDL National Science Digital Library
Jo Edkins
2006-01-01
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.)
Tomographic Representation of Quantum Mechanics and Statistical Physics
Olga V. Man'ko
2009-02-26
A review of the photon-number tomography and symplectic tomography as examples of star-product quantization is presented. The classical statistical mechanics is considered within the framework of the tomographic representation.
Piepel, Gregory F.; Matzke, Brett D.; Sego, Landon H.; Amidan, Brett G.
2013-04-27
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.
Number of minerals of various chemical elements: Statistics 2012 (a new approach to an old problem)
NASA Astrophysics Data System (ADS)
Krivovichev, V. G.; Charykova, M. V.
2014-12-01
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.
Getting the numbers right: statistical mischief and racial profiling in heart failure research.
Kahn, Jonathan
2003-01-01
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
SCHOOL OF MATHEMATICS AND STATISTICS Autumn Semester Topics in Number Theory 2 hours 30 minutes
Pythagorean triples which include 225. (11 marks) (ii) State Fermat's Last Theorem. Is it possible to have's Little Theorem. (1 mark) (a) Determine the remainder when 20082008 is divided by 143. (7 marks) (b Wilson's Theorem. (1 mark) Show that, for every prime number p, 1 + 1 2 + 1 3 + Â· Â· Â· + 1 p
Statistical lower bounds on protein copy number from fluorescence expression images
Lee Zamparo; Theodore J. Perkins
2009-01-01
Motivation: Fluorescence imaging has become commonplace for quantitatively measuring mRNA or protein expression in cells and tissues. However, such expression data is usually relative—absolute concentrations or molecular copy numbers are typically not known. While this is satisfactory for many applications, for certain kinds of quantitative network modeling and analysis of expression noise, absolute measures of expression are necessary. Results: We
SCHOOL OF MATHEMATICS AND STATISTICS Autumn 2007-2008 Topics in Number Theory 2 hours
) (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
A Statistical Analysis for Estimating Fish Number Density with the Use of a Multibeam Echosounder
NASA Astrophysics Data System (ADS)
Schroth-Miller, Madeline L.
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.
NASA Astrophysics Data System (ADS)
Marusic, Ivan; Hutchins, Nicholas
2007-11-01
An investigation was conducted of the logarithmic layer structure in turbulent boundary layers spanning three orders of magnitude change in Reynolds number. This was achieved by using two laboratory scale facilities and the atmospheric surface layer at the SLTEST facility in Utah. Several experimental techniques were used including particle image velocimetry in the laboratory, and spanwise and wall-normal arrays of hot-wires and sonic anemometers in the laboratory and atmosphere, respectively. Two-point correlation statistics are found to agree extremely over all Reynolds numbers with outer length scaling. Recent large-scale coherence noted in the logarithmic region of laboratory-scale boundary layers (superstructures) are also found to exist in the atmospheric surface layer flow.
Leon-Saval, Sergio; Bland-Hawthorn, Joss
2015-01-01
Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus, enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail.
NASA Astrophysics Data System (ADS)
Gounhalli, Shivraj G.; Shantappa, Anil; Hanagodimath, S. M.
2013-04-01
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.
... 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 ...
Boyer, Edmond
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
NASA Astrophysics Data System (ADS)
Hao, Longjie; Min, Lequan
2014-06-01
Recently, a stream encryption scheme using d-bit segment sequences has been proposed. This scheme may generate key avalanche effect. The randomness tests of d-bit segment pseudorandom number generator will be important for implementing such a scheme. Firstly this paper extends Beker and Piper's binary pseudorandom sequence statistical test suite to d-bit segment sequences case. Secondly, a novel 3-dimensional polynomial discrete chaotic map (3DPDCM) is proposed. The calculated Lyapunov exponents of the 3DPCDM are 0.213, 0.125 and - 3.228. Using the 3DPDCM constructs a 6-dimensional generalized synchronization chaotic system. Based on this system, a 8-bit segment chaotic pseudorandom number generator (CPRNG) is introduced. Using the generalized test suite tests 100 key streams generated via the 8-bit PRNG with different initial conditions and perturbed system parameters. The tested results are similar to those of the key streams generated via RC4 PRNG. As an application, using the key streams generated via the CPRNG and the RC4 PRNG encrypts an RGB image Landscape. The results have shown that the encrypted RGB images have significant avalanche effects. This research suggests that the requirements for PRNGs are not as strict as those under the traditional avalanche criteria. Suitable designed chaos-based d-bit string PRNGs may be qualified candidates for the stream encryption scheme with avalanche effect.
G. Zaccanti; E. Battistelli; P. Bruscaglioni; Q. Wei
1994-01-01
Some statistical relationships relating the optical properties of the diffusing medium to the first and second moments of the coordinates of the points at which the different scattering orders occur are presented. These relationships give qualitative information on the spatial broadening of a light beam propagating in a diffusive medium and can be very useful to test the reliability of
Photon counting statistics of V-type three-level systems:The effects of the field fluctuations
NASA Astrophysics Data System (ADS)
Peng, Yong-Gang; Zheng, Yu-Jun
2015-02-01
We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems. The emission intensity I and Mandel's Q parameter show stochastic resonance with respect to the pure dephasing constant ?p. The amplitude fluctuation of the field causes these systems to lose their coherence. On the other hand, the amplitude fluctuation provides a new interference method for these systems. The quantum beats are shown in the orthogonal system. Project supported by the National Natural Science Foundation of China (Grand Nos. 91021009, 21073110, and 11374191), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2013AQ020), the Postdoctoral Science Foundation of China (Grant No. 2013M531584), and the Doctoral Program of Higher Education of China (Grant Nos. 20130131110005 and 20130131120006).
A High Speed, Post-Processing Free, Quantum Random Number Generator
J. F. Dynes; Z. L. Yuan; A. W. Sharpe; A. J. Shields
2008-07-25
A quantum random number generator (QRNG) based on gated single photon detection of an InGaAs photodiode at GHz frequency is demonstrated. Owing to the extremely long coherence time of each photon, each photons' wavefuntion extends over many gating cycles of the photodiode. The collapse of the photon wavefunction on random gating cycles as well as photon random arrival time detection events are used to generate sequences of random bits at a rate of 4.01 megabits/s. Importantly, the random outputs are intrinsically bias-free and require no post-processing procedure to pass random number statistical tests, making this QRNG an extremely simple device.
Photon Clusters in Thermal Radiation
Aleksey Ilyin
2014-10-30
Within the framework of Bose-Einstein statistics, it is shown that the blackbody radiation, in addition to single photons, contains photon clusters, or coalescent photons. The probability to find a k-photon cluster versus radiation frequency and temperature is found, as well as the statistics of clusters. Spectra of photon-cluster radiation are calculated as functions of blackbody temperature. The Planck's radiation law is derived based on the existence of photon clusters. The possibility of experimental observation of photon clusters in thermal radiation is discussed.
Properties of two-mode squeezed number states
NASA Technical Reports Server (NTRS)
Chizhov, Alexei V.; Murzakhmetov, B. K.
1994-01-01
Photon statistics and phase properties of two-mode squeezed number states are studied. It is shown that photon number distribution and Pegg-Barnett phase distribution for such states have similar (N + 1)-peak structure for nonzero value of the difference in the number of photons between modes. Exact analytical formulas for phase distributions based on different phase approaches are derived. The Pegg-Barnett phase distribution and the phase quasiprobability distribution associated with the Wigner function are close to each other, while the phase quasiprobability distribution associated with the Q function carries less phase information.
NSDL National Science Digital Library
Hoffman, Howard
This site contains 100 modules designed to introduce concepts in statistics. The modules are divided into categories such as descriptive statistics, inferential statistics, related measures, enumeration statistics and ANOVA. Click the green button on the side to start the modules, then click "Main Menu" at the top to see a list of topics. Topics include: describing numbers, normal curve, sampling distributions, hypothesis testing, regression and Chi-Square. The site also includes a glossary, statistical tables and simulations, and a personalized progress report.
NASA Technical Reports Server (NTRS)
Kraft, Ralph P.; Burrows, David N.; Nousek, John A.
1991-01-01
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.
Andrei Khrennikov
2014-12-27
In this paper we present results of numerical simulation based on Prequantum Classical Statistical Field Theory (PCSFT), a model with hidden variables of the field-type reproducing probabilistic predictions of quantum mechanics (QM). PCSFT is combined with measurement theory based on detectors of the threshold type. The latter describes discrete events corresponding to the continuous fields model, PCSFT. Numerical modeling demonstrated that the classical Brownian motion (the Wiener process valued in complex Hilbert space) producing clicks when approaching the detection threshold gives probabilities of detection predcited by the formalism QM (as well as PCSFT). This numerical result is important, since the transition from PCSFT to the threshold detection has a complex mathematical structure (in the framework of classical random processes) and it was modeled only approximately. We also perform numerical simulation for the PCSFT-value of the coefficient of second order coherence. Our result matches well with the prediction of quantum theory. Thus, opposite to semiclassical theory, PCSFT cannot be rejected as a consequence of measurements of $g^{(2)}(0).$ Finally, we analyze the output of the recent experiment performed in NIST questioning the validity of some predictions of PCSFT.
Photonic quantum well composed of photonic crystal and quasicrystal
NASA Astrophysics Data System (ADS)
Xu, Shaohui; Zhu, Yiping; Wang, Lianwei; Yang, Pingxiong; Chu, Paul K.
2014-02-01
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.
Alain Connes; Matilde Marcolli
2004-01-01
This is the first installment of a paper in three parts, where we use noncommutative geometry to study the space of commensurability classes of Q-lattices and we show that the arithmetic properties of KMS states in the corresponding quantum statistical mechanical system, the theory of modular Hecke algebras, and the spectral realization of zeros of L-functions are part of a
Skin Conditions of Youths 12-17, United States. Vital and Health Statistics; Series 11, Number 157.
ERIC Educational Resources Information Center
Roberts, Jean; Ludford, Jacqueline
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,…
U.S. Students Abroad: Statistics on Study Abroad, 1985/86. IIE Research Report Number 16.
ERIC Educational Resources Information Center
Zikopoulos, Marianthi, Ed.
Statistics are provided on U.S. students overseas, with data coming from the Study Abroad Survey, a survey of 2,896 accredited U.S. institutions of higher education with 1,898 responding for a 65% response rate. Details are provided on the characteristics and destinations of the 48,483 students abroad. Reasons for the increase in study abroad…
Willig, Michael
Home Range Size in Eastern Chipmunks, Tamias striatus, as a Function of Number of Captures #12;HOME RANGE SIZE IN EASTERN CHIPMUNKS, TAMIAS STRIATUS, AS A FUNCTION O F NUMBER O F CAPTURES to identify factors accounting for variation in home range size. Home range is linearly dependent upon
Périco, Cintia Azevedo-Marques; Skaf, Cesar R; Yamada, Airton; Duran, Fábio; Buchpiguel, Carlos A; Castro, Cláudio C; Soares, Jair C; Busatto, Geraldo F
2005-08-26
This study examined the relationship between resting regional cerebral blood flow (rCBF) patterns in patients with major depressive disorder (MDD) and specific symptom clusters derived from ratings on the Hamilton Rating Scale for Depression (HRSD) and the Mini Mental State Examination. We hypothesized that the functional activity in frontal, parietal, anterior cingulate, basal ganglia and limbic regions would be related to specific symptom domains. Fifteen patients fulfilling DSM-IV criteria for MDD who were off all psychotropic medications for >4 weeks and 15 normal volunteers were recruited. Single photon emission computed tomography (SPECT) images were obtained after (99m)Tc-ECD injection, and correlations between rCBF patterns and symptom severity ratings were calculated on a voxel-by-voxel basis, using statistical parametric mapping (SPM). Severity of depressive mood was inversely correlated with rCBF in the left amygdala, lentiform nucleus, and parahippocampal gyrus, and directly correlated with rCBF in the right postero-lateral parietal cortex (p < 0.001, uncorrected for multiple comparisons). Insomnia severity was inversely correlated with rCBF in the right rostral and subgenual anterior cingulate cortices, insula and claustrum. Anxiety severity was directly correlated with rCBF in the right antero-lateral orbitofrontal cortex, while cognitive performance was directly correlated with rCBF in the right postero-medial orbitofrontal cortex and in the left lentiform nucleus. Our findings confirmed the prediction that separate symptom domains of the MDD syndrome are related to specific rCBF patterns, and extend results from prior studies that suggested the involvement of anterior cingulate, frontal, limbic and basal ganglia regions in the pathophysiology of MDD. PMID:15921853
Ivan Marusic; Nicholas Hutchins
2007-01-01
An investigation was conducted of the logarithmic layer structure in turbulent boundary layers spanning three orders of magnitude change in Reynolds number. This was achieved by using two laboratory scale facilities and the atmospheric surface layer at the SLTEST facility in Utah. Several experimental techniques were used including particle image velocimetry in the laboratory, and spanwise and wall-normal arrays of
Gheorghe Savoiu
2006-01-01
The number of the human population had reunited both in its quantitative side, and, especially, in the qualitative one, the most significant aspects of the various and detailed human evolution and dynamic. This demographic and synthetic indicator allowed a detailed and original process of population segmentation in the field of the contemporary analysis. Referring to a new process of demographic
A bias free true random number generator
Wei Wei; Hong Guo
2009-05-15
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.
Dhar, S.
1989-02-01
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.
T. Yamamoto; K. Sugiyama
1975-01-01
Making use of a model based on the statistical theory in which the scission-point distance is treated as an adjustable parameter, calculations were performed to obtain the mass yields of fission products, the kinetic energies of fission fragments and the numbers of prompt neutrons from neutron-induced fission of Â²Â³Â²Th, Â²Â³Â¹Pa, Â²Â³Â³U, Â²Â³âµU, Â²Â³â¸U, Â²Â³â·Np, Â²Â³â¹Pu and Â²â´Â¹Pu for incident-neutron energies
Richard S. Savage; Seb Oliver
2005-11-14
We perform fluctuation analyses on the data from the Spitzer GOODS survey (epoch one) in the Hubble Deep Field North (HDF-N). We fit a parameterised power-law number count model of the form dN/dS = N_o S^{-\\delta} to data from each of the four Spitzer IRAC bands, using Markov Chain Monte Carlo (MCMC) sampling to explore the posterior probability distribution in each case. We obtain best-fit reduced chi-squared values of (3.43 0.86 1.14 1.13) in the four IRAC bands. From this analysis we determine the likely differential faint source counts down to $10^{-8} Jy$, over two orders of magnitude in flux fainter than has been previously determined. From these constrained number count models, we estimate a lower bound on the contribution to the Infra-Red (IR) background light arising from faint galaxies. We estimate the total integrated background IR light in the Spitzer GOODS HDF-N field due to faint sources. By adding the estimates of integrated light given by Fazio et al (2004), we calculate the total integrated background light in the four IRAC bands. We compare our 3.6 micron results with previous background estimates in similar bands and conclude that, subject to our assumptions about the noise characteristics, our analyses are able to account for the vast majority of the 3.6 micron background. Our analyses are sensitive to a number of potential systematic effects; we discuss our assumptions with regards to noise characteristics, flux calibration and flat-fielding artifacts.
NSDL National Science Digital Library
Kirkman, Thomas
This collection of calculators, created by Thomas Kirkman of the College of Saint Bendict/Saint Joseph, allows users to perform a number of statistical applications. Each provides background on the procedure and an example. Users can compute descriptive statistics and perform t-tests, Chi-square tests, Kolmogorov-Smirnov tests, Fisher's Exact Test, contingency tables, ANOVA, and regression. This is a nice collection of useful applications for a statistics classroom.
Statistics of multiphoton events in spontaneous parametric down-conversion
Wojciech Wasilewski; Czeslaw Radzewicz; Robert Frankowski; Konrad Banaszek
2008-05-12
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.
On the Poisson Approximation to Photon Distribution for Faint Lasers
Yucheng Hu; Xiang Peng; Tiejun Li; Hong Guo
2006-09-23
It is proved, that for a certain kind of input distribution, the strongly binomially attenuated photon number distribution can well be approximated by a Poisson distribution. This explains why we can adopt poissonian distribution as the photon number statistics for faint lasers. The error of such an approximation is quantitatively estimated. Numerical tests are carried out, which coincide with our theoretical estimations. This work lays a sound mathematical foundation for the well-known intuitive idea which has been widely used in quantum cryptography.
Low-bias high-speed quantum random number generator via shaped optical pulses.
Wayne, Michael A; Kwiat, Paul G
2010-04-26
We present an optical quantum random number generator (QRNG) based on the digitized time interval between random photon arrivals. By tailoring the photon flux of the laser diode, the statistics of the waiting-time distribution are altered to approximate the ideal, uniform case. This greatly reduces the need for post-processing, and enables fast, secure quantum random number generation at rates exceeding 110 Mbit/s. PMID:20588781
Hybrid laser with CMOS photonics
Chong, Johanna S
2014-01-01
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 ...
Photon scattering from strongly driven atomic ensembles
Jin Luling [Max-Planck Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Department of Physics, Northwest University, Xi'an 710069, Shaanxi (China); Evers, Joerg; Macovei, Mihai [Max-Planck Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)
2011-10-15
The second-order correlation function for light emitted from a strongly and near-resonantly driven dilute cloud of atoms is discussed. Because of the strong driving, the fluorescence spectrum separates into distinct peaks, for which the spectral properties can be defined individually. It is shown that the second-order correlations for various combinations of photons from different spectral lines exhibit bunching together with super-Poissonian or sub-Poissonian photon statistics, tunable by the choice of the detector positions. Additionally, a Cauchy-Schwarz inequality is violated for photons emitted from particular spectral bands. The emitted light intensity is proportional to the square of the number of particles, and thus can potentially be intense. Three different averaging procedures to model ensemble disorder are compared.
Brodsky, S.J.
1988-07-01
Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.
NSDL National Science Digital Library
M. Fisher
2007-12-04
Let\\'s have some fun working on our math facts and putting numbers together to get new ones! Try out these games and see how you do-- First try to defeat this spaceship with your math fact skills: Spacey Math: A drill game where students are given a set of math facts to answer (can select addition, subtraction, multiplication, division). If you defeat the spaceship you can move on to helping save the poodles. They have to weigh in and they need to find out what numbers need to go on the other side of the scale to balance ...
Statistics of a Stokes-Antistokes Interacting Boson System with Damping
K. Germey; F.-J. Schütte; R. Tiebel
1981-01-01
The statistics of a system of four boson modes in Stokes-Antistokes interaction is considered with respect to the influence of damping in one mode. The time evolution of the system is calculated. The mean particle numbers and the factorial moments of photon number distribution are calculated. Numerical results show strong dependence on bath temperature but only weak influence of the
STATISTICAL METHODS STATISTICAL METHODS
Delorme, Arnaud
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
NASA Astrophysics Data System (ADS)
Siegel, Z.; Carl-Ludwig Siegel, Edward
2011-03-01
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!!!
Statistics 580 Random Number Generation
Vaswani, Namrata
of integers and depends upon x0 : a seed a : a multiplier c : a shift m : a modulus all of which are also that perform well on some tests. Another choice for m is a large prime p, whence the period is p - 1 if the multiplier is chosen to be its primitive root. Primes of the form 2p - 1, called Mersenne primes
Photonic Aharonov–Bohm effect in photon–phonon interactions
Li, Enbang; Eggleton, Benjamin J.; Fang, Kejie; Fan, Shanhui
2014-01-01
The Aharonov–Bohm effect is one of the most intriguing phenomena in both classical and quantum physics, and associates with a number of important and fundamental issues in quantum mechanics. The Aharonov–Bohm effects of charged particles have been experimentally demonstrated and found applications in various fields. Recently, attention has also focused on the Aharonov–Bohm effect for neutral particles, such as photons. Here we propose to utilize the photon–phonon interactions to demonstrate that photonic Aharonov–Bohm effects do exist for photons. By introducing nonreciprocal phases for photons, we observe experimentally a gauge potential for photons in the visible range based on the photon–phonon interactions in acousto-optic crystals, and demonstrate the photonic Aharonov–Bohm effect. The results presented here point to new possibilities to control and manipulate photons by designing an effective gauge potential. PMID:24476790
Brodsky, S.J.
1985-01-01
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.
Induced photon decay and photon-beam-induced Langmuir turbulence
D. B. Melrose
1994-01-01
A pair of quasi-linear-like equations is derived to describe the effect of three-wave interactions between high-frequency photons and Langmuir waves in a differential approximation. Induced photon decay leads to terms analogous to those for spontaneous emission, but involving the square of the photon occupation number. The effect on the Langmuir waves is evaluated for axisymmetric photons. The effect on the
PHYSICS LETTERS 3 December 1973Volume 46A, number 2 PHOTON ECHOES IN LaF3 :Nd3+ AND YAG:Nd3+*
+ in the three crystalline hosts. The photon echo amplitude in each crystal de- pended upon both magnetic field, Columbia University, New York, N. Y. 10027, USA Received 1 October 1973 Magnetic field and temperature on sample tempera- ture and applied magnetic field. In all three crystals, the ground state 419,2 is split
Nonclassical properties and decoherence of fields in photon-added squeezing-enhanced thermal states
NASA Astrophysics Data System (ADS)
Wang, Zhen; Meng, Xiang-Guo; Li, Heng-Mei; Yuan, Hong-Chun
2014-04-01
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.
Thermodynamics of a photon gas and deformed dispersion relations
A. Camacho; A. Macias
2007-02-28
We resort to the methods of statistical mechanics in order to determine the effects that a deformed dispersion relation has upon the thermodynamics of a photon gas. The ensuing modifications to the density of states, partition function, pressure, internal energy, entropy, and specific heat are calculated. It will be shown that the breakdown of Lorentz invariance can be interpreted as a repulsive interaction, among the photons. Additionally, it will be proved that the presence of a deformed dispersion relation entails an increase in the entropy of the system. In other words, as a consequence of the loss of the aforementioned symmetry the number of microstates available to the corresponding equilibrium state grows.
Photon blockade effect in optomechanical systems.
Rabl, P
2011-08-01
We analyze the photon statistics of a weakly driven optomechanical system and discuss the effect of photon blockade under single-photon strong coupling conditions. We present an intuitive interpretation of this effect in terms of displaced oscillator states and derive analytic expressions for the cavity excitation spectrum and the two-photon correlation function g(2)(0). Our results predict the appearance of nonclassical photon correlations in the combined strong coupling and sideband resolved regime and provide a first detailed understanding of photon-photon interactions in strong coupling optomechanics. PMID:21902322
Photon Blockade Effect in Optomechanical Systems
NASA Astrophysics Data System (ADS)
Rabl, P.
2011-08-01
We analyze the photon statistics of a weakly driven optomechanical system and discuss the effect of photon blockade under single-photon strong coupling conditions. We present an intuitive interpretation of this effect in terms of displaced oscillator states and derive analytic expressions for the cavity excitation spectrum and the two-photon correlation function g(2)(0). Our results predict the appearance of nonclassical photon correlations in the combined strong coupling and sideband resolved regime and provide a first detailed understanding of photon-photon interactions in strong coupling optomechanics.
PHOTONIC NANOJET PHOTONIC NANOJET
Poon, Andrew Wing On
experiment Novel experiment ShadowgraphShadowgraph Nano-indented slit scanning Nano-indented slit scanning). LASER illumination Photonic nanojet phenomena Optical fiber-based micro-cylinder lens #12;PHOTONICNANOJET SHADOWGRAPH AFM TIP SCANNING NANO-INDENTED SLIT SCANNING SIMULATION EXPERIMENTS 1Âµm 500nm SEM
Finding the boson-number distributions in superconducting thin-film rings
NASA Astrophysics Data System (ADS)
Agafonov, A. I.
2014-09-01
A theory of the infrared (IR)-field-induced single-photon generation by the narrow thin-film superconducting rings made of the isotropic s-wave pairing type-II superconductors is presented. It is shown that statistical measurements of the energies of photons emitted by the same current-carrying ring prepared initially in the same quantum state, allow to find the number distribution of Cooper pairs in the superconductor.
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.
The thermalization, condensation and flickering of photons
NASA Astrophysics Data System (ADS)
Klaers, Jan
2014-12-01
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.
G. David; for the PHENIX Collaboration
2008-10-21
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 ($p_T$) 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 $p_T$ 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 $e^+e^-$ 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
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.
Experimental validation of photonic boson sampling
NASA Astrophysics Data System (ADS)
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
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.
ERIC Educational Resources Information Center
Snyder, Thomas D.; Dillow, Sally A.
2012-01-01
The 2011 edition of the "Digest of Education Statistics" is the 47th in a series of publications initiated in 1962. The "Digest" has been issued annually except for combined editions for the years 1977-78, 1983-84, and 1985-86. Its primary purpose is to provide a compilation of statistical information covering the broad field…
ERIC Educational Resources Information Center
Snyder, Thomas D.; Dillow, Sally A.
2013-01-01
The 2012 edition of the "Digest of Education Statistics" is the 48th in a series of publications initiated in 1962. The "Digest" has been issued annually except for combined editions for the years 1977-78, 1983-84, and 1985-86. Its primary purpose is to provide a compilation of statistical information covering the broad field…
NSDL National Science Digital Library
John Brignell, Professor Emeritus from the Department of Electronics & Computer Science at the University of Southampton, is the author of this informal website "devoted to the monitoring of the misleading numbers that rain down on us via the media." Brignell says he aims to "nail" a few of the "Single Issue Fanatics (SIFs), politicians, bureaucrats, quasi-scientists (junk, pseudo- or just bad)," who use misleading numbers to write catchy articles or who try to keep numbers away from public notice. Since April 2000, he has been posting a "number of the month" as well as a "number for the year," which offer his commentary on media usage of misleading numbers and explanations for why the numbers are misleading. He also posts book reviews and an extensive list of online resources on statistics and statistics education. The FAQ section includes answers to some interesting questions, such as "Is there such a thing as average global temperature?" and some more basic questions such as "What is the Normal Distribution and what is so normal about it?" The Bits and Pieces section includes a variety of short articles on statistics and his definitions for some terms he uses on the website. Visitors are also invited to join the discussion forum (complete with a few advertisements) and view comments by others who want to discuss "wrong numbers in science, politics and the media." A few comments sent to Brignell and his responses are also posted online. This site is also reviewed in the February 11, 2005_NSDL MET Report_.
Nonreciprocal magnetic photonic crystals
A. Figotin; I. Vitebsky
2001-01-01
We study band dispersion relations omega(k-->) of a photonic crystal with at least one of the constitutive components being a magnetically ordered material. It is shown that by proper spatial arrangement of magnetic and dielectric components one can construct a magnetic photonic crystal with strong spectral asymmetry (nonreciprocity) omega(k-->)!=omega(-k-->). The spectral asymmetry, in turn, results in a number of interesting
Multiple-Photon Absorption Attack on Entanglement-Based Quantum Key Distribution Protocols
Guillaume Adenier; Irina Basieva; Andrei Yu. Khrennikov; Masanori Ohya; Noboru Watanabe
2011-02-16
In elaborating on the multiple-photon absorption attack on Ekert protocol proposed in arXiv:1011.4740, we show that it can be used in other entanglement-based protocols, in particular the BBM92 protocol. In this attack, the eavesdropper (Eve) is assumed to be in control of the source, and she sends pulses correlated in polarization (but not entangled) containing several photons at frequencies for which only multiple-photon absorptions are possible in Alice's and Bob's detectors. Whenever the photons stemming from one pulse are dispatched in such a way that the number of photons is insufficient to trigger a multiple-photon absorption in either channel, the pulse remains undetected. We show that this simple feature is enough to reproduce the type of statistics on the detected pulses that are considered as indicating a secure quantum key distribution, even though the source is actually a mixture of separable states. The violation of Bell inequalities measured by Alice and Bob increases with the order of the multiple-photon absorption that Eve can drive into their detectors, while the measured quantum bit error rate decreases as a function of the same variable. We show that the attack can be successful even in the simplest case of a two-photon absorption or three-photon absorption attack, and we discuss possible countermeasures, in particular the use of a fair sampling test.
J. D. Joannopoulos; Pierre R. Villeneuve; Shanhui Fan
1997-01-01
A new class of composite materials has emerged which provides a means to control and manipulate light. These materials, known as photonic crystals, are periodic arrays of dielectric scatteres in homogeneous dielectric matrices. They affect the properties of photons in much the same way a semiconductor affects the properties of an electron. Consequently, photons can have band structures, localized defect
Statistical Applets: Statistical Significance
NSDL National Science Digital Library
Duckworth, William
Created by authors Duckworth, McCabe, Moore and Sclove for W.H. Freeman of Co., this applet is designed to help students visualize the rejection region of a statistical test by allowing them to set null and alternate hypotheses, population parameters, sample statistics, and significance level. It accompanies "Â?Â?Practice of Business Statistics," but can be used without this text. Even though brief, this is a nice interactive resource for an introductory statistics course.
Detector noise statistics in the non-linear regime
NASA Technical Reports Server (NTRS)
Shopbell, P. L.; Bland-Hawthorn, J.
1992-01-01
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.
Statistics and Statistical Mechanics
Pierre Collet; Jean-Pierre Eckmann
This chapter is somewhat more technical than the earlier ones. Its aim is to discuss some more recent results in dynamical\\u000a systems which refine our knowledge of statistical properties. These results follow from a combination of methods from statistics\\u000a and statistical mechanics.
Statistics in a Trilinear Interacting Stokes-Antistokes Boson System
W. Tänzler; F.-J. Schütte
1981-01-01
The statistics of a system of four boson modes is treated with simultaneous Stokes-Antistokes interaction taking place. The time evolution is calculated in full quantum manner but in short time approximation. Mean photon numbers and correlations of second order are calculated. Antibunching can be found in the laser mode and in the system of Stokes and Antistokes mode.Translated AbstractStatistik in
Statistical Applets: Animated Exercise
NSDL National Science Digital Library
Duckworth, William
This collection of statistical applets is designed to accompany the textbook, "Practice of Business Statistics." The applets can be used without the textbook and cover many introductory statistics concepts including mean, normal curve, correlation and regression, probability, the law of large numbers, the central limit theorem, confidence intervals, statistical significance, power, and ANOVA. This is a great collection of interactive materials for either instructors or students studying statistics.
Hansen, John P
2003-01-01
Healthcare quality improvement professionals need to understand and use inferential statistics to interpret sample data from their organizations. In quality improvement and healthcare research studies all the data from a population often are not available, so investigators take samples and make inferences about the population by using inferential statistics. This three-part series will give readers an understanding of the concepts of inferential statistics as well as the specific tools for calculating confidence intervals for samples of data. This article, Part 2, describes probability, populations, and samples. The uses of descriptive and inferential statistics are outlined. The article also discusses the properties and probability of normal distributions, including the standard normal distribution. PMID:14606210
Quantum Storage of a Photonic Polarization Qubit in a Solid
Mustafa Gündo?an; Patrick M. Ledingham; Attaallah Almasi; Matteo Cristiani; Hugues de Riedmatten
2012-01-20
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 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 mu=0.4. This is significantly higher than a classical benchmark, taking into account the Poissonian statistics and finite memory efficiency, which proves that our device functions as a quantum storage device for polarization qubits, even if tested with weak coherent states. These results extend the storage capabilities of solid state quantum memories to polarization encoding, which is widely used in quantum information science.
Controllable stimulation of retinal rod cells using single photons
Nam Mai Phan; Mei Fun Cheng; Dmitri A. Bessarab; Leonid A. Krivitsky
2014-04-29
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.
Photon-photon scattering in collisions of laser pulses
B. King; C. H. Keitel
2012-02-15
A scenario for measuring the predicted processes of vacuum elastic and inelastic photon-photon scattering with modern lasers is investigated. Numbers of measurable scattered photons are calculated for the collision of two, Gaussian-focused, pulsed lasers. We show that a single 10PW optical laser beam split into two counter-propagating pulses is sufficient for measuring the elastic process. Moreover, when these pulses are sub-cycle, our results suggest the inelastic process should be measurable too.
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
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.
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
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.; Whiting, Bruce R.; O’Sullivan, Joseph A.; Politte, David G.; Klahr, Paul H.; Yu, Yaduo; Williamson, Jeffrey F.
2013-01-01
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
Velchik, M.G.
1987-01-01
Recently, there has been a renewed interest in the detection and treatment of osteoporosis. This paper is a review of the merits and limitations of the various noninvasive modalities currently available for the measurement of bone mineral density with special emphasis placed upon the nuclear medicine techniques of single-photon and dual-photon absorptiometry. The clinicians should come away with an understanding of the relative advantages and disadvantages of photon absorptiometry and its optimal clinical application. 49 references.
ERIC Educational Resources Information Center
National Institutes of Health (DHEW), Bethesda, MD. Bureau of Health Professions Education and Manpower Training.
This publication is a compilation of statistics on supply and education of health manpower in medicine and osteopathy, dentistry, optometry, pharmacy, podiatry, veterinary medicine, nursing, public health, and eight selected allied health occupations. The material is organized by occupations and the following information is presented for each…
Quantum Interference Induced Photon Blockade in a Coupled Single Quantum Dot-Cavity System
Tang, Jing; Geng, Weidong; Xu, Xiulai
2015-01-01
We propose an experimental scheme to implement a strong photon blockade with a single quantum dot coupled to a nanocavity. The photon blockade effect can be tremendously enhanced by driving the cavity and the quantum dot simultaneously with two classical laser fields. This enhancement of photon blockade is ascribed to the quantum interference effect to avoid two-photon excitation of the cavity field. Comparing with Jaynes-Cummings model, the second-order correlation function at zero time delay g(2)(0) in our scheme can be reduced by two orders of magnitude and the system sustains a large intracavity photon number. A red (blue) cavity-light detuning asymmetry for photon quantum statistics with bunching or antibunching characteristics is also observed. The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field. Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system. This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing. PMID:25783560
Quantum interference induced photon blockade in a coupled single quantum dot-cavity system.
Tang, Jing; Geng, Weidong; Xu, Xiulai
2015-01-01
We propose an experimental scheme to implement a strong photon blockade with a single quantum dot coupled to a nanocavity. The photon blockade effect can be tremendously enhanced by driving the cavity and the quantum dot simultaneously with two classical laser fields. This enhancement of photon blockade is ascribed to the quantum interference effect to avoid two-photon excitation of the cavity field. Comparing with Jaynes-Cummings model, the second-order correlation function at zero time delay g((2))(0) in our scheme can be reduced by two orders of magnitude and the system sustains a large intracavity photon number. A red (blue) cavity-light detuning asymmetry for photon quantum statistics with bunching or antibunching characteristics is also observed. The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field. Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system. This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing. PMID:25783560
Quantum Interference Induced Photon Blockade in a Coupled Single Quantum Dot-Cavity System
NASA Astrophysics Data System (ADS)
Tang, Jing; Geng, Weidong; Xu, Xiulai
2015-03-01
We propose an experimental scheme to implement a strong photon blockade with a single quantum dot coupled to a nanocavity. The photon blockade effect can be tremendously enhanced by driving the cavity and the quantum dot simultaneously with two classical laser fields. This enhancement of photon blockade is ascribed to the quantum interference effect to avoid two-photon excitation of the cavity field. Comparing with Jaynes-Cummings model, the second-order correlation function at zero time delay g(2)(0) in our scheme can be reduced by two orders of magnitude and the system sustains a large intracavity photon number. A red (blue) cavity-light detuning asymmetry for photon quantum statistics with bunching or antibunching characteristics is also observed. The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field. Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system. This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing.
Photon-timing jitter dependence on the injection position in single-photon avalanche diodes
NASA Astrophysics Data System (ADS)
Assanelli, Mattia; Ingargiola, Antonino; Rech, Ivan; Gulinatti, Angelo; Ghioni, Massimo
2010-04-01
In recent years a growing number of applications demands always better timing resolution for Single Photon Avalanche Diodes. The challenge is pursuing the improved timing resolution without impairing the other device characteristics such as quantum efficiency and dark counts. This task requires a clear understanding of the physical mechanisms necessary to drive the device engineering process. Past studies state that in Si-SPADs the avalanche injection position statistics is the main contribution to the photon-timing jitter. However, in recent re-engineered devices, this assumption is questioned. For the purpose of assessing for good this contribution we developed an experimental setup in order to characterize the photontiming jitter as a function of the injection position by means of TCSPC measurements with a laser focused on the device active area. Results confirmed not only that the injection position is not the main contribution to the photon-timing jitter but also evidenced a radial dependence never observed before. Furthermore we found a relation between the photon-timing jitter and the specific resistance of the devices. To characterize the resistances we studied the avalanche current density distribution in the device active area by imaging the photo-luminescence due to hot-carrier emission.
Breakdown of bose-einstein distribution in photonic crystals.
Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min
2015-01-01
In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed. PMID:25822135
Breakdown of Bose-Einstein Distribution in Photonic Crystals
Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min
2015-01-01
In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed. PMID:25822135
Two-photon and three-photon blockades in driven nonlinear systems
Adam Miranowicz; Malgorzata Paprzycka; Yu-xi Liu; Jiri Bajer; Franco Nori
2013-03-26
Photon blockade, in analogy to Coulomb's or phonon blockades, is a phenomenon when a single photon in a nonlinear cavity blocks the transmission of a second photon. This effect can occur in Kerr-type systems driven by a laser due to strong nonlinear photon-photon interactions. We predict the occurrence of higher-order photon blockades where the transmission of more than two photons is effectively blocked by single- and two-photon states. This photon blockade can be achieved by tuning the frequency of the laser driving field to be equal to the sum of the Kerr nonlinearity and the cavity resonance frequency. We refer to this phenomenon as two-photon blockade or two-photon state truncation via nonlinear scissors, and can also be interpreted as photon-induced tunneling. We also show that, for a driving-field frequency fulfilling another resonance condition and for higher strengths of the driving field, even a three-photon blockade can occur but less clearly than in the case of single- and two-photon blockades. We demonstrate how various photon blockades can be identified by analyzing photon-number correlations, coherence and entropic properties, Wigner functions, and spectra of squeezing. We show that two- and three-photon blockades can, in principle, be observed in various cavity and circuit quantum electrodynamical systems for which the standard single-photon blockade was observed without the need of using higher-order driving interactions or Kerr media exhibiting higher-order nonlinear susceptibility.
NASA Astrophysics Data System (ADS)
Andrews, David L.
2009-08-01
In recent years it has become evident that the primary concept of the photon has multiple interpretations, with widely differing secondary connotations. Despite the all-pervasive nature of this concept in science, some of the ancillary properties with which the photon is attributed in certain areas of application sit uneasily alongside those invoked in other areas. Certainly the range of applications extends far beyond what was envisaged in the original conception, now entering subjects extending from elementary particle physics and cosmology through to spectroscopy, statistical mechanics and photochemistry. Addressing this diverse context invites the question: What is there, that it is possible to assert as incontrovertibly true about the photon? Which properties are non-controversial, if others are the subject of debate? This paper describes an attempt to answer these questions, establishing as far as possible an irreducible core of what can rightly be asserted about the photon, and setting aside some of what often is, but should never be so asserted. Some of the more bewildering difficulties and differences of interpretation owe their origin to careless descriptions, highlighting a need to guard semantic precision; although simplifications are frequently and naturally expedient for didactic purposes, they carry the risk of becoming indelible. Focusing on such issues, the aim is to identify how much or how little about the photon can be regarded as truly non-controversial.
Photonic Astronomy and Quantum Optics
Dainis Dravins
2007-01-09
Quantum optics potentially offers an information channel from the Universe beyond the established ones of imaging and spectroscopy. All existing cameras and all spectrometers measure aspects of the first-order spatial and/or temporal coherence of light. However, light has additional degrees of freedom, manifest in the statistics of photon arrival times, or in the amount of photon orbital angular momentum. Such quantum-optical measures may carry information on how the light was created at the source, and whether it reached the observer directly or via some intermediate process. Astronomical quantum optics may help to clarify emission processes in natural laser sources and in the environments of compact objects, while high-speed photon-counting with digital signal handling enables multi-element and long-baseline versions of the intensity interferometer. Time resolutions of nanoseconds are required, as are large photon fluxes, making photonic astronomy very timely in an era of large telescopes.
Nonclassicality and decoherence of photon-subtracted squeezed states
NASA Astrophysics Data System (ADS)
Biswas, Asoka; Agarwal, Girish S.
2007-03-01
Single-photon subtracted squeezed vacuum states are equivalent to Schrodinger kitten states and show non-Gaussian nature in phase space. Such states are useful in entanglement distillation, loophole-free test of Bell's inequality, and quantum computing. We discuss nonclassical properties of these states in terms of the sub-Poissonian statistics and the negativity of the Wigner function. We derive a compact expression for the Wigner function from which we find the region of phase space where Wigner function is negative. We find an upper bound on the squeezing parameter for the state to exhibit sub-Poissonian statistics. We then study the effect of decoherence on the single-photon subtracted squeezed states. We present results for two different models of decoherence, viz. amplitude decay model and the phase diffusion model. In each case we give analytical results for the time evolution of the state. We discuss the loss of nonclassicality as a result of decoherence. We show through the study of their phase-space properties how these states decay to vacuum due to the decay of photons. We show that phase damping leads to very slow decoherence than the photon-number decay and the state remains nonclassical at long times.
Vladimir A Kuznetsov; Onkar Singh; Piroon Jenjaroenpun
2010-01-01
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
Gregg, B. A.; van de Lagemaat, J.
2012-05-01
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.
NSDL National Science Digital Library
Center for Materials and Devices for Information Technology Research
The Photonics Wiki is large collection of articles, images and media assembled by the NSF Center for Material and Devices for Information Technology Research (CMDITR). It covers core concepts in photonics, non-linear optics and devices as well as other professional development resources for undergraduate and graduate level.
Anders Bjarklev; Andrei Lavrinenko
2001-01-01
The first concept of what we now call photonic crystals arose 14 years ago and has been maturing in the literature ever since. Indeed, in optoelectronic literature photonic crystals can now compete with personal computers for the abbreviation `PC'. Early thoughts included a set of very pronounced publications by V P Bykov in the mid 1970s but only the papers
Gauthier, Daniel
by the atomic Zeeman degeneracy. We conjecture that the laser could emit polarization-entangled twin beams for these differences is that the two-photon stimulated emission rate depends quadratically on the incident photon flux
Sze Kui Ng
2011-02-28
It is shown that a photon with a specific frequency can be identified with the Dirac magnetic monopole. When a Dirac-Wilson line forms a Dirac-Wilson loop, it is a photon. This loop model of photon is exactly solvable. From the winding numbers of this loop-form of photon, we derive the quantization properties of energy and electric charge. A new QED theory is presented that is free of ultraviolet divergences. The Dirac-Wilson line is as the quantum photon propagator of the new QED theory from which we can derive known QED effects such as the anomalous magnetic moment and the Lamb shift. The one-loop computation of these effects is simpler and is more accurate than that in the conventional QED theory. Furthermore, from the new QED theory, we have derived a new QED effect. A new formulation of the Bethe-Salpeter (BS) equation solves the difficulties of the BS equation and gives a modified ground state of the positronium. By the mentioned new QED effect and by the new formulation of the BS equation, a term in the orthopositronium decay rate that is missing in the conventional QED is found, resolving the orthopositronium lifetime puzzle completely. It is also shown that the graviton can be constructed from the photon, yielding a theory of quantum gravity that unifies gravitation and electromagnetism.
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 â??Alliancesâ? 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.
NASA Astrophysics Data System (ADS)
Yeung, Pui-Kuen; Donzis, D. A.; Sreenivasan, K. R.; Sawford, B. L.; Pope, S. B.
2010-11-01
Rapid advances in Cyberinfrastructure, with more to come on the horizon, are presenting many opportunities for extending simulations of turbulence towards previously inaccessible parameter regimes and improved results in problems with greater complexity. In our group we have performed 4096^3 simulations of isotropic turbulence on three massively parallel machines to study turbulence at higher Reynolds number, higher Schmidt number, or better resolution than usually practiced. One topic studied is Batchelor scaling and small-scale intermittency of passive scalar fields in turbulent mixing at high Schmidt number with a demonstrable viscous-convective range. Another is the behavior of Lagrangian structure functions at high Reynolds number (R? 1000), with conditional sampling used to distinguish between the characteristics of strain-dominated versus rotation-dominated regions of the flow. We shall discuss both problems briefly, and conclude with an overview of current and future challenges involved in striving towards the next level, involving Petascale computing and beyond.
On the Doppler effect for photons in rotating systems
Giuliani, Giuseppe
2015-01-01
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,...
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Active Temporal Multiplexing of Photons
Gabriel J. Mendoza; Raffaele Santagati; Jack Munns; Elizabeth Hemsley; Mateusz Piekarek; Enrique Martin-Lopez; Graham D. Marshall; Damien Bonneau; Mark G. Thompson; Jeremy L. O'Brien
2015-03-04
Quantum information science promises powerful new technologies and fundamental scientific discoveries. Photonic qubits are appealing for their low noise properties-the cost is the non-deterministic nature of many processes, including photon generation and entanglement. Active multiplexing can increase the success probability of such processes above a required threshold, and spatial multiplexing of up to four heralded photon sources shows great promise. The cost is a proliferation of hardware. Temporal multiplexing-repeated use of the same hardware components-has been proposed as an alternative and is likely to be essential to greatly reduce resource complexity and system sizes. Requirements include the precise synchronization of a system of low-loss switches, delay lines, fast photon detectors, and feed-forward. Here we demonstrate multiplexing of 8 'bins'-four temporal and two spatial-from a heralded photon source. We show enhanced photon emission statistics, observing an increase in both the triggering and heralded photon rates. Despite its current limitations due to extrinsic sources of loss, this system points the way to harnessing temporal multiplexing in quantum technologies, from single-photon sources to large-scale computation.
Single-photon filtering by a cavity quantum electrodynamics system
Koshino, Kazuki [College of Liberal Arts and Sciences, Tokyo Medical and Dental University, 2-8-30 Konodai, Ichikawa 272-0827 (Japan) and PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 (Japan)
2008-02-15
The nonlinear dynamics of a classical photon pulse in a cavity-QED system is investigated theoretically. It is shown that this system can work as a single-photon filter, which drastically suppresses the multiple-photon probability of the output. The output photon statistics is sensitive to the input pulse length. A suitable choice of pulse length produces a photon pulse with the single-photon probability of 0.32, while the multiple-photon probability is suppressed to 0.01.
Resonant Photonic States in Coupled Heterostructure Photonic Crystal Waveguides
2010-01-01
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
A Photon Interference Detector with Continuous Display.
ERIC Educational Resources Information Center
Gilmore, R. S.
1978-01-01
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)
NASA Astrophysics Data System (ADS)
Chough, Young-Tak
2014-05-01
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.
Srinivasan-Rao, Triveni (Shoreham, NY)
2002-01-01
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.
Nonreciprocal magnetic photonic crystals
Figotin, A.; Vitebsky, I.
2001-06-01
We study band dispersion relations {omega}({rvec k}) of a photonic crystal with at least one of the constitutive components being a magnetically ordered material. It is shown that by proper spatial arrangement of magnetic and dielectric components one can construct a magnetic photonic crystal with strong spectral asymmetry (nonreciprocity) {omega}({rvec k}){ne}{omega}({minus}{rvec k}). The spectral asymmetry, in turn, results in a number of interesting phenomena, in particular, one-way transparency when the magnetic photonic crystal, being perfectly transparent for a Bloch wave of frequency {Omega}, {open_quotes}freezes{close_quotes} the radiation of the same frequency {Omega} propagating in the opposite direction. The frozen radiation corresponds to a Bloch wave with zero group velocity {partial_derivative}{omega}(k)/{partial_derivative}k=0 and, in addition, with {partial_derivative}{sup 2}{omega}(k)/{partial_derivative}k{sup 2}=0.
Nonreciprocal magnetic photonic crystals.
Figotin, A; Vitebsky, I
2001-06-01
We study band dispersion relations omega(k-->) of a photonic crystal with at least one of the constitutive components being a magnetically ordered material. It is shown that by proper spatial arrangement of magnetic and dielectric components one can construct a magnetic photonic crystal with strong spectral asymmetry (nonreciprocity) omega(k-->) not equal omega(-k-->). The spectral asymmetry, in turn, results in a number of interesting phenomena, in particular, one-way transparency when the magnetic photonic crystal, being perfectly transparent for a Bloch wave of frequency omega, "freezes" the radiation of the same frequency omega propagating in the opposite direction. The frozen radiation corresponds to a Bloch wave with zero group velocity partial differential omega(k)/ partial differential k=0 and, in addition, with partial differential(2)omega(k)/ partial differential k(2)=0. PMID:11415244
Modeling of dye-laser photon statistics
Fabio Marchesoni; Theoretische Physik
1986-01-01
We propose a model for dye lasers operating at resonance with a non-Gaussian fluctuating pump parameter. Analytical and numerical results are compared with recent experimental measurements on the intensity fluctuations of a dye laser and with previous theoretical predictions based on a fluctuating pump parameter of finite correlation time.
Convergence Rates for $U$Statistics and Related Statistics
William F. Grams; R. J. Serfling
1973-01-01
Bounds are provided for the rates of convergence in the central limit theorem and the strong law of large numbers for $U$-statistics. The results are obtained by establishing suitable bounds upon the moments of the difference between a $U$-statistic and its projection. Analogous conclusions for the associated von Mises statistical functions are indicated. Statistics considered for exemplification are the sample
Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector
NASA Technical Reports Server (NTRS)
Huntington, Andrew
2013-01-01
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.
Third-order antibunching from an imperfect single-photon source.
Stevens, Martin J; Glancy, Scott; Nam, Sae Woo; Mirin, Richard P
2014-02-10
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
NASA Astrophysics Data System (ADS)
Tsia, Kevin K.; Jalali, Bahram
2010-05-01
An intriguing optical property of silicon is that it exhibits a large third-order optical nonlinearity, with orders-ofmagnitude larger than that of silica glass in the telecommunication band. This allows efficient nonlinear optical interaction at relatively low power levels in a small footprint. Indeed, we have witnessed a stunning progress in harnessing the Raman and Kerr effects in silicon as the mechanisms for enabling chip-scale optical amplification, lasing, and wavelength conversion - functions that until recently were perceived to be beyond the reach of silicon. With all the continuous efforts developing novel techniques, nonlinear silicon photonics is expected to be able to reach even beyond the prior achievements. Instead of providing a comprehensive overview of this field, this manuscript highlights a number of new branches of nonlinear silicon photonics, which have not been fully recognized in the past. In particular, they are two-photon photovoltaic effect, mid-wave infrared (MWIR) silicon photonics, broadband Raman effects, inverse Raman scattering, and periodically-poled silicon (PePSi). These novel effects and techniques could create a new paradigm for silicon photonics and extend its utility beyond the traditionally anticipated applications.
MCNP: Photon benchmark problems
Whalen, D.J.; Hollowell, D.E.; Hendricks, J.S.
1991-09-01
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.
Engineering nonlinear coherent states as photon-added and photon-subtracted coherent states
NASA Astrophysics Data System (ADS)
Ramos-Prieto, I.; Rodríguez-Lara, B. M.; Moya-Cessa, H. M.
2014-11-01
We propose a class of nonlinear coherent states which are experimentally feasible in cavity or ion-trap quantum electrodynamics. These quantum field states arise from a new type of photon addition and subtraction based on London phase operators, also known as Susskind-Glogower operators, that just displaces the mean photon number without scaling the photon distribution.
Looking into the collapse of quantum states with entangled photons
M. G. M. Moreno; Fernando Parisio
2013-03-12
We propose a scheme to investigate the time scale of the wave-function collapse by using polarization-entangled photon pairs. The setup is similar to those employed to investigate quantum correlations, but in the present case, synchronization is essential at all stages. We find that it is possible to discriminate between the scenarios of instantaneous collapse and finite-time reduction via a large number of double measurements of polarization. The quantities to be recorded would present distinct behaviors in each scenario, the deviations being small but distinguishable from pure statistical fluctuations.
Single photon interference Single photon interference
Spagnolo, Filippo
Single photon interference Single photon interference with a Fresnel biprism Contacts: Jean-FranÃ§ois Roch FranÃ§ois Treussart Philippe Grangier Introduction Single photon source Interference fringes Anticorrelation Archives Single-photon interference Single photons emitted by the N-V colour centre are sent
Measurement of photon correlations with multipixel photon counters
Dmitry Kalashnikov; Leonid A. Krivitsky
2014-08-01
Development of reliable photon number resolving detectors (PNRD), devices which are capable to distinguish 1,2,3.. photons, is of a great importance for quantum optics and its applications. A new class of affordable PNRD is based on multipixel photon counters (MPPC). Here we review results of experiments on using MPPCs for direct characterization of squeezed vacuum (SV) states, generated via parametric downconversion (PDC). We use MPPCs to measure the second order normalized intensity correlation function (g^(2)) and directly detect the two-mode squeezing of SV states. We also present a method of calibration of crosstalk probability in MPPCs based on g^(2) measurements of coherent states.
Lakes, Roderic
experimental approach based on a toroid Cavendish balance is used to evaluate the product of photon mass). More stringent limits based on inference from large-scale magnetic features in astro- nomical plasma be linked to photon mass. The Heisen- berg uncertainty principle gives the smallest measurable mass
Department of Statistics STATISTICS COLLOQUIUM
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
Photonic Bandgaps in Photonic Molecules
NASA Technical Reports Server (NTRS)
Smith, David D.; Chang, Hongrok; Gates, Amanda L.; Fuller, Kirk A.; Gregory, Don A.; Witherow, William K.; Paley, Mark S.; Frazier, Donald O.; Curreri, Peter A. (Technical Monitor)
2002-01-01
This talk will focus on photonic bandgaps that arise due to nearly free photon and tight-binding effects in coupled microparticle and ring-resonator systems. The Mie formulation for homogeneous spheres is generalized to handle core/shell systems and multiple concentric layers in a manner that exploits an analogy with stratified planar systems, thereby allowing concentric multi-layered structures to be treated as photonic bandgap (PBG) materials. Representative results from a Mie code employing this analogy demonstrate that photonic bands arising from nearly free photon effects are easily observed in the backscattering, asymmetry parameter, and albedo for periodic quarter-wave concentric layers, though are not readily apparent in extinction spectra. Rather, the periodicity simply alters the scattering profile, enhancing the ratio of backscattering to forward scattering inside the bandgap, in direct analogy with planar quarter-wave multilayers. PBGs arising from tight-binding may also be observed when the layers (or rings) are designed such that the coupling between them is weak. We demonstrate that for a structure consisting of N coupled micro-resonators, the morphology dependent resonances split into N higher-Q modes, in direct analogy with other types of oscillators, and that this splitting ultimately results in PBGs which can lead to enhanced nonlinear optical effects.
Photonic Floquet topological insulators
NASA Astrophysics Data System (ADS)
Rechtsman, Mikael C.; Zeuner, Julia M.; Plotnik, Yonatan; Lumer, Yaakov; Podolsky, Daniel; Dreisow, Felix; Nolte, Stefan; Segev, Mordechai; Szameit, Alexander
2013-09-01
Topological insulators are a new phase of matter, with the striking property that conduction of electrons occurs only on the surface. In two dimensions, surface electrons in topological insulators do not scatter despite defects and disorder, providing robustness akin to superconductors. Topological insulators are predicted to have wideranging applications in fault-tolerant quantum computing and spintronics. Recently, large theoretical efforts were directed towards achieving topological insulation 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. However, since magnetic effects are very weak at optical frequencies, realizing photonic topological insulators with scatterfree edge states requires a fundamentally different mechanism - one that is free of magnetic fields. Recently, a number of proposals for photonic topological transport have been put forward. Specifically, one suggested temporally modulating 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, where temporal variations in solidstate systems induce topological edge states. Here, we propose and experimentally demonstrate the first external field-free photonic topological insulator 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 acts as `time'. Thus the waveguides' helicity breaks zreversal symmetry in the sense akin to Floquet Topological Insulators. This structure results in scatter-free, oneway edge states that are topologically protected from scattering.
Photon blockade in the ultrastrong coupling regime.
Ridolfo, A; Leib, M; Savasta, S; Hartmann, M J
2012-11-01
We explore photon coincidence counting statistics in the ultrastrong coupling regime, where the atom-cavity coupling rate becomes comparable to the cavity resonance frequency. In this regime, usual normal order correlation functions fail to describe the output photon statistics. By expressing the electric-field operator in the cavity-emitter dressed basis, we are able to propose correlation functions that are valid for arbitrary degrees of light-matter interaction. Our results show that the standard photon blockade scenario is significantly modified for ultrastrong coupling. We observe parametric processes even for two-level emitters and temporal oscillations of intensity correlation functions at a frequency given by the ultrastrong photon emitter coupling. These effects can be traced back to the presence of two-photon cascade decays induced by counterrotating interaction terms. PMID:23215383
Deconstructing Statistical Analysis
ERIC Educational Resources Information Center
Snell, Joel
2014-01-01
Using a very complex statistical analysis and research method for the sake of enhancing the prestige of an article or making a new product or service legitimate needs to be monitored and questioned for accuracy. 1) The more complicated the statistical analysis, and research the fewer the number of learned readers can understand it. This adds a…
Development of Magnetic Materials for Photonic Applications
NASA Astrophysics Data System (ADS)
Baert, Kasper; Libaers, Wim; Kolaric, Branko; Vallée, Renaud A. L.; van der Auweraer, Mark; Clays, Koen; Grandjean, Didier; di Vece, Marcel; Lievens, Peter
In this manuscript, the synthesis and characterization of superparamagnetic particles and their silica-coated counterparts as building blocks for magnetic photonic crystals is fully described. The advantages and disadvantages of the presented synthetic method are discussed. Preliminary results considering the presence of magnetic species within a photonic crystal are also presented. Suppression of emission of the quantum dots within photonic crystals is attributed to a decrease of the number of available photonic modes for radiative decay. The presence of materials with permanent magnetic moments within photonic crystals shows that suppression of their emission is scaled with the strength of the magnetic field.
Statistical Geneticist: Janet Sinsheimer
NSDL National Science Digital Library
2012-05-02
This is a PDF interview, PowerPoint slide set, and webpage biography of a statistical geneticist, detailing the importance of scientists fluent in the analysis of numbers to organize data and design studies.
PHOTON SCIENCES DIRECTORATE ADVANCED PHOTON SOURCE
Kemner, Ken
PHOTON SCIENCES DIRECTORATE ADVANCED PHOTON SOURCE G. B. STEPHENSON ASSOCIATE LABORATORY DIRECTOR DIRECTOR, ADVANCED PHOTON SOURCE (VACANT) D. M. MILLS G. SRAJER Deputy Assoc. Lab. Dir. Deputy Assoc. Lab
Mario Stip?evi?; John Bowers
2014-10-09
We present a random number generator based on quantum effects in photonic emission and detection. It is unique in simultaneous use of both spatial and temporal quantum information contained in the system which makes it resilient to hardware failure and signal injection attacks. We show that its deviation from randomness cam be estimated based on simple measurements. Generated numbers pass NIST Statistical test suite without post-processing.
Dilated Networks for Photonic Switching
K. Padmanabhan; A. Netravali
1987-01-01
We present some novel architectures for rearrangeably nonblocking multistage photonic space switches implemented using arrays ofTi:LiNbO_{3}directional couplers. Multistage networks, studied mostly in the electronic domain, are obtained by minimizing the number of 2 × 2 elements needed to implement a switch. Unfortunately, straightforward extensions of these networks to the photonic domain show that the switch size has to be severely
Statistical Applets: Two Variable Statistical Calculator
NSDL National Science Digital Library
Duckworth, William
Created by Duckworth, McCabe, Moore and Sclove for W.H. Freeman and Co., this applet calculates correlation and regression information and displays graphs for a number of data sets from the text "Â?Â?Practice of Business Statistics."Â?Â Users can also enter their own data. Even though brief, this interactive resource is still valuable for an introductory statistics course.
Investigation of variance reduction techniques for Monte Carlo photon dose calculation using XVMC
NASA Astrophysics Data System (ADS)
Kawrakow, Iwan; Fippel, Matthias
2000-08-01
Several variance reduction techniques, such as photon splitting, electron history repetition, Russian roulette and the use of quasi-random numbers are investigated and shown to significantly improve the efficiency of the recently developed XVMC Monte Carlo code for photon beams in radiation therapy. It is demonstrated that it is possible to further improve the efficiency by optimizing transport parameters such as electron energy cut-off, maximum electron energy step size, photon energy cut-off and a cut-off for kerma approximation, without loss of calculation accuracy. These methods increase the efficiency by a factor of up to 10 compared with the initial XVMC ray-tracing technique or a factor of 50 to 80 compared with EGS4/PRESTA. Therefore, a common treatment plan (6 MV photons, 10×10 cm2 field size, 5 mm voxel resolution, 1% statistical uncertainty) can be calculated within 7 min using a single CPU 500 MHz personal computer. If the requirement on the statistical uncertainty is relaxed to 2%, the calculation time will be less than 2 min. In addition, a technique is presented which allows for the quantitative comparison of Monte Carlo calculated dose distributions and the separation of systematic and statistical errors. Employing this technique it is shown that XVMC calculations agree with EGSnrc on a sub-per cent level for simulations in the energy and material range of interest for radiation therapy.
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
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.
Gabriel Molina-Terriza; Juan P. Torres; Lluis Torner
2007-01-01
The orbital angular momentum of light represents a fundamentally new optical degree of freedom. Unlike linear momentum, or spin angular momentum, which is associated with the polarization of light, orbital angular momentum arises as a subtler and more complex consequence of the spatial distribution of the intensity and phase of an optical field - even down to the single photon
December 2000 A STATISTICAL TEST
December 2000 A STATISTICAL TEST SUITE FOR RANDOM AND PSEUDORANDOM NUMBER GENERATORS challenges in authentication protocols. NIST Special Publication (SP) 800-22, A Statistical Test Suite testing of random number and pseudorandom number generators (RNGs and PRNGs) that may be used for many
Signal acquisition via polarization modulation in single photon sources
Mark D. McDonnell; Adrian P. Flitney
2009-11-26
A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than one bit per sample is to be transmitted, and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector's photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N. Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains.
The 'Pile-up Effect' in Photon Detection
Madsen, A.; Zontone, F.; Gruebel, G. [European Synchrotron Radiation Facility, B. P. 220, F-38043 Grenoble (France); Als-Nielsen, J. [Niels Bohr Institute, Orsted Laboratory, DK-2100 Copenhagen O (Denmark)
2004-05-12
We quantify the pile-up of X-ray photons in a single-photon-counting detector with finite dead-time when subject to an intense synchrotron beam of non-Poisson distributed photons. The pile-up leads to a non-linearity between the registered count-rate and the true photon-rate when a single-channel analyzer is employed and we show that the phenomenon can be described by use of a simple statistical model.
Limits of heralded single-photon sources based on parametric photon-pair generation
Virally, Stephane; Lacroix, Suzanne; Godbout, Nicolas [COPL, Departement de Genie Physique, Ecole Polytechnique de Montreal, Case Postale 6079, Succursale Centre-Ville, Montreal, Quebec H3C 3A7 (Canada)
2010-01-15
We derive calculations on the statistics of a heralded single-photon source based on parametric photon-pair generation. These calculations highlight fundamental and practical limits for these sources and show which physical parameters can be optimized to improve the quality of a real source.
NASA Astrophysics Data System (ADS)
Andersen, Geoff; Tullson, Drew
2006-06-01
In designing next-generation, ultra-large (>20m) apertures for space, many current concepts involve compactable, curved membrane reflectors. Here we present the idea of using a flat diffractive element that requires no out-of-plane deformation and so is much simpler to deploy. The primary is a photon sieve - a diffractive element consisting of a large number of precisely positioned holes distributed according to an underlying Fresnel Zone Plate (FZP) geometry. The advantage of the photon sieve over the FZP is that all the regions are connected, so the membrane substrate under simple tension can avoid buckling. Also, the hole distribution can be varied to generate any conic or apodization for specialized telescope requirements such as exo-solar planet detection. We have designed and tested numerous photon sieves as telescope primaries. Some of these have over 10 million holes in a 0.1 m diameter aperture and all of them give diffraction limited imaging. While photon sieves are diffractive elements and thus suffer from dispersion, we will present two successful solutions to this problem.
Generalized quantum interference of correlated photon pairs
Heonoh Kim; Sang Min Lee; Han Seb Moon
2015-03-30
Superposition and indistinguishablility between probability amplitudes have played an essential role in observing quantum interference effects of correlated photons. The Hong-Ou-Mandel interference and interferences of the path-entangled photon number state are of special interest in the field of quantum information technologies. However, a fully generalized two-photon quantum interferometric scheme accounting for the Hong-Ou-Mandel scheme and path-entangled photon number states has not yet been proposed. Here we report the experimental demonstrations of the generalized two-photon interferometry with both the interferometric properties of the Hong-Ou-Mandel effect and the fully unfolded version of the path-entangled photon number state using photon-pair sources, which are independently generated by spontaneous parametric down-conversion. Our experimental scheme explains two-photon interference fringes revealing single- and two-photon coherence properties in a single interferometer setup. Using the proposed interferometric measurement, it is possible to directly estimate the joint spectral intensity of a photon pair source.
Di-photon and photon + b/c production cross sections at Ecm = 1.96- TeV
Gajjar, Anant; /Liverpool U.
2005-05-01
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.
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
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
Frozen photons in Jaynes Cummings arrays
N. Schetakis; T. Grujic; S. R. Clark; D. Jaksch; D. G. Angelakis
2013-06-02
We study the origin of "frozen" states in coupled Jaynes-Cummings-Hubbard arrays in the presence of losses. For the case of half the array initially populated with photons while the other half is left empty we show the emergence of self-localized photon or "frozen" states for specific values of the local atom-photon coupling. We analyze the dynamics in the quantum regime and discover important additional features appear not captured by a semiclassical treatment, which we analyze for different array sizes and filling fractions. We trace the origin of this interaction-induced photon "freezing" to the suppression of excitation of propagating modes in the system at large interaction strengths. We discuss in detail the possibility to experimentally probe the relevant transition by analyzing the emitted photon correlations. We find a strong signature of the effect in the emitted photons statistics.
Multi-element superconducting nanowire single photon detectors
Dauler, Eric A. (Eric Anthony), 1980-
2009-01-01
Single-photon-detector arrays can provide unparalleled performance and detailed information in applications that require precise timing and single photon sensitivity. Such arrays have been demonstrated using a number of ...
Chaos due to parametric excitation: phase space symmetry and photon correlations
T. V. Gevorgyan; G. H. Hovsepyan; A. R. Shahinyan; G. Yu. Kryuchkyan
2014-07-29
We discuss dissipative chaos showing symmetries in the phase space and nonclassical statistics for a parametrically driven nonlinear Kerr resonator (PDNR). In this system an oscillatory mode is created in the process of degenerate down-conversion of photons under interaction with a train of external Gaussian pulses. For chaotic regime we demonstrate, that the Poincar\\'e section showing a strange attractor, as well as the resonator mode contour plots of the Wigner functions display two-fold symmetry in the phase space. We show that quantum-to-classical correspondence is strongly violated for some chaotic regimes of the PDNR. Considering the second-order correlation function we show that the high-level of photons correlation leading to squeezing in the regular regime strongly decreases if the system transits to the chaotic regime. Thus, observation of the photon-number correlation allows to extract information about the chaotic regime.
José Lebreuilly; Iacopo Carusotto; Michiel Wouters
2015-02-13
We report a theoretical study of a quantum optical model consisting of an array of strongly nonlinear cavities incoherently pumped by an ensemble of population-inverted two-level atoms. Projective methods are used to eliminate the atomic dynamics and write a generalized master equation for the photonic degrees of freedom only, where the frequency-dependence of gain introduces non-Markovian features. In the simplest single cavity configuration, this pumping scheme allows for the selective generation of Fock states with a well-defined photon number. For many cavities in a weakly non-Markovian limit, the non-equilibrium steady state recovers a Grand-Canonical statistical ensemble at a temperature determined by the effective atomic linewidth. For a two-cavity system in the strongly nonlinear regime, signatures of a Mott state with one photon per cavity are found.
nature photonics | VOL 6 | FEBRUARY 2012 | www.nature.com/naturephotonics 75 news & views
Hone, James
nature photonics | VOL 6 | FEBRUARY 2012 | www.nature.com/naturephotonics 75 news & views c avity of single photons, as well as cavityexciton photon blockade and tunnelling7 on a semiconductor chip demonstrated highly efficient quantum dot single-photon sources with sub-Poissonian statistics8 . Now, writing
ERIC Educational Resources Information Center
Hanford, Terry; White, Kathleen
1991-01-01
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…
NASA Astrophysics Data System (ADS)
Vasdekis, A. E.; Scott, E. A.; Roke, S.; Hubbell, J. A.; Psaltis, D.
2013-07-01
Amphiphiles, under appropriate conditions, can self-assemble into nanoscale thin membrane vessels (vesicles) that encapsulate and hence protect and transport molecular payloads. Vesicles assemble naturally within cells but can also be artificially synthesized. In this article, we review the mechanisms and applications of light-field interactions with vesicles. By being associated with light-emitting entities (e.g., dyes, fluorescent proteins, or quantum dots), vesicles can act as imaging agents in addition to cargo carriers. Vesicles can also be optically probed on the basis of their nonlinear response, typically from the vesicle membrane. Light fields can be employed to transport vesicles by using optical tweezers (photon momentum) or can directly perturb the stability of vesicles and hence trigger the delivery of the encapsulated payload (photon energy). We conclude with emerging vesicle applications in biology and photochemical microreactors.
NASA Astrophysics Data System (ADS)
Floume, Timmy; Coquil, Thomas; Sylvestre, Julien
2011-05-01
Due to their metabolic flexibility and fast growth rate, microscopic aquatic phototrophs like algae have a potential to become industrial photochemical converters. Algae photosynthesis could enable the large scale production of clean and renewable liquid fuels and chemicals with major environmental, economic and societal benefits. Capital and operational costs are the main issues to address through optical, process and biochemical engineering improvements. In this perspective, a variety of photonic approaches have been proposed - we introduce them here and describe their potential, limitations and compatibility with separate biotechnology and engineering progresses. We show that only sunlight-based approaches are economically realistic. One of photonics' main goals in the algae field is to dilute light to overcome photosaturation effects that impact upon cultures exposed to full sunlight. Among other approaches, we introduce a widely-compatible broadband spectral adaptation technique called AlgoSun® that uses luminescence to optimize sunlight spectrum in view of the bioconverter's requirements.
Integrated spatial multiplexing of heralded single-photon sources
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
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
Va`vra, J.
1995-10-01
J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF{sub 2} windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission.
NASA Astrophysics Data System (ADS)
Liu, Timon C.; Li, Fan-Hui
2010-11-01
Photonic homeostatics is a discipline to study the establishment, maintenance, decay, upgrading and representation of function-specific homoestasis (FSH) by using photonics. FSH is a negative-feedback response of a biosystem to maintain the function-specific fluctuations inside the biosystem so that the function is perfectly performed. A stress may increase sirtuin 1 (SIRT1) activities above FSH-specific SIRT1 activity to induce a function far from its FSH. On the one hand, low level laser irradiation or monochromatic light (LLL) can not modulate a function in its FSH or a stress in its stress-specific homeostasis (StSH), but modulate a function far from its FSH or a stress far from its StSH. On the other hand, the biophotons from a biosystem with its function in its FSH should be less than the one from the biosystem with its function far from its FSH. The non-resonant interaction of low intensity laser irradiation or monochromatic light (LIL) and a kind of membrane protein can be amplified by all the membrane proteins if the function is far from its FSH. This amplification might hold for biophoton emission of the membrane protein so that the photonic spectroscopy can be used to represent the function far from its FSH, which is called photonomics.
Using high-power lasers for detection of elastic photon-photon scattering
E. Lundstrom; G. Brodin; J. Lundin; M. Marklund; R. Bingham; J. Collier; J. T. Mendonca; P. Norreys
2006-02-01
The properties of four-wave interaction via the nonlinear quantum vacuum is investigated. The effect of the quantum vacuum is to generate photons with new frequencies and wave vectors, due to elastic photon-photon scattering. An expression for the number of generated photons is derived and using state-of-the-art laser data it is found that the number of photons can reach detectable levels. In particular, the prospect of using the high repetition Astra Gemini system at the Rutherford Appleton Laboratory is discussed. The problem of noise sources is reviewed, and it is found that the noise level can be reduced well below the signal level. Thus, detection of elastic photon-photon scattering may for the first time be achieved.
Statistics Anxiety and Business Statistics: The International Student
ERIC Educational Resources Information Center
Bell, James A.
2008-01-01
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…
Q Fever: Statistics and Epidemiology
... Reading Statistics and Epidemiology Annual Cases of Q Fever in the United States Q fever was first ... Q fever. Figure 1 - Number of U.S. Q Fever cases* reported to CDC, 1998 – 2010. *Numbers presented ...
Better Randomness with Single Photons
Lukas Oberreiter; Ilja Gerhardt
2014-11-13
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.
ERIC Educational Resources Information Center
Callamaras, Peter
1983-01-01
This buyer's guide to seven major types of statistics software packages for microcomputers reviews Edu-Ware Statistics 3.0; Financial Planning; Speed Stat; Statistics with DAISY; Human Systems Dynamics package of Stats Plus, ANOVA II, and REGRESS II; Maxistat; and Moore-Barnes' MBC Test Construction and MBC Correlation. (MBR)
NASA Astrophysics Data System (ADS)
Lyons, M.; Carl-Ludwig Siegel, Edward
2011-03-01
Weiss-Page-Holthaus[Physica A,341,586(04); http://arxiv.org/abs/cond-mat/0403295] number-FACTORIZATION VIA BEQS BEC VS.(?) Shor-algorithm, strongly-supporting Watkins' [www.secamlocal.ex.ac.uk/people/staff/mrwatkin/] Intersection of number-theory "pure"-maths WITH (Statistical)-Physics, as Siegel[AMS Joint.Mtg.(02)-Abs.973-60-124] Benford logarithmic-law algebraic-INVERSION to ONLY BEQS with d=0 digit
=oo gapFUL BEC!!! Siegel Riemann-hypothesis proof via Rayleigh[Phil.Trans.CLXI(1870)]-Polya[Math.Ann.(21)]-[Random-Walks & Electric-Nets., MAA(81)]-"Anderson"[PRL(58)]-localization-Siegel[Symp.Fractals,MRS Fall Mtg.(89)-5-papers!!!] FUZZYICS=CATEGORYICS: [LOCALITY]--MORPHISM/CROSSOVER/ AUTMATHCAT/DIM-CAT/ ANTONYM-->(GLOBALITY) FUNCTOR/SYNONYM/ concomitance to "noise"<=/Fluct.-Dissip. theorem/ FUNCTOR/SYNONYM/ equivalence/proportionality to => "generalized-susceptibility" power-spectrum [FLAT/FUNCTIONLESS/WHITE]--MORPHISM/ CROSSOVER/AUTMATHCAT/DIM-CAT/ANTONYM--> HYPERBOLICITY/ZIPF-law INEVITABILITY) intersection with ONLY BEQS BEC).
Thermal noise and correlations in photon detection
Jonas Zmuidzinas
2003-01-01
The standard expressions for the noise that is due to photon fluctuations in thermal background radiation typically apply only for a single detector and are often strictly valid only for single-mode illumination. I describe a technique for rigorously calculating thermal photon noise, which allows for arbitrary numbers of optical inputs and detectors, multiple-mode illumination, and both internal and external noise
Photon Orbital Angular Momentum in Astrophysics
Martin Harwit
2003-07-24
Astronomical observations of the orbital angular momentum of photons, a property of electromagnetic radiation that has come to the fore in recent years, have apparently never been attempted. Here, I show that measurements of this property of photons have a number of astrophysical applications.
Lithography system using quantum entangled photons
NASA Technical Reports Server (NTRS)
Williams, Colin (Inventor); Dowling, Jonathan (Inventor); della Rossa, Giovanni (Inventor)
2002-01-01
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.
Light scattering from ultracold atoms in optical lattices as an optical probe of quantum statistics
Mekhov, Igor B. [Institut fuer Theoretische Physik, Universitaet Innsbruck, Innsbruck (Austria); Faculty of Physics, St. Petersburg State University, St. Petersburg (Russian Federation); Maschler, Christoph; Ritsch, Helmut [Institut fuer Theoretische Physik, Universitaet Innsbruck, Innsbruck (Austria)
2007-11-15
We study off-resonant collective light scattering from ultracold atoms trapped in an optical lattice. Scattering from different atomic quantum states creates different quantum states of the scattered light, which can be distinguished by measurements of the spatial intensity distribution, quadrature variances, photon statistics, or spectral measurements. In particular, angle-resolved intensity measurements reflect global statistics of atoms (total number of radiating atoms) as well as local statistical quantities (single-site statistics even without optical access to a single site) and pair correlations between different sites. As a striking example we consider scattering from transversally illuminated atoms into an optical cavity mode. For the Mott-insulator state, similar to classical diffraction, the number of photons scattered into a cavity is zero due to destructive interference, while for the superfluid state it is nonzero and proportional to the number of atoms. Moreover, we demonstrate that light scattering into a standing-wave cavity has a nontrivial angle dependence, including the appearance of narrow features at angles, where classical diffraction predicts zero. The measurement procedure corresponds to the quantum nondemolition measurement of various atomic variables by observing light.
Instant single-photon Fock state tomography
Huisman, S R; Babichev, S A; Vewinger, Frank; Zhang, A N; Youn, S H; Lvovsky, A I
2009-01-01
Heralded single photons are prepared at a rate of ~100 kHz via conditional measurements on polarization-nondegenerate biphotons produced in a periodically poled KTP crystal. The single-photon Fock state is characterized using high frequency pulsed optical homodyne tomography with a fidelity of (57.6 +- 0.1)%. The state preparation and detection rates allowed us to perform on-the-fly alignment of the apparatus based on real-time analysis of the quadrature measurement statistics.
Instant single-photon Fock state tomography
S. R. Huisman; Nitin Jain; S. A. Babichev; Frank Vewinger; A. N. Zhang; S. H. Youn; A. I. Lvovsky
2009-06-02
Heralded single photons are prepared at a rate of ~100 kHz via conditional measurements on polarization-nondegenerate biphotons produced in a periodically poled KTP crystal. The single-photon Fock state is characterized using high frequency pulsed optical homodyne tomography with a fidelity of (57.6 +- 0.1)%. The state preparation and detection rates allowed us to perform on-the-fly alignment of the apparatus based on real-time analysis of the quadrature measurement statistics.
Spindel, Jennifer; Begum, Hasina; Akdemir, Deniz; Virk, Parminder; Collard, Bertrand; Redoña, Edilberto; Atlin, Gary; Jannink, Jean-Luc; McCouch, Susan R.
2015-01-01
Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline. PMID:25689273
Sub-Poissonian statistics of Rydberg-interacting dark-state polaritons.
Hofmann, C S; Günter, G; Schempp, H; Robert-de-Saint-Vincent, M; Gärttner, M; Evers, J; Whitlock, S; Weidemüller, M
2013-05-17
We observe individual dark-state polaritons as they propagate through an ultracold atomic gas involving Rydberg states coupled via an electromagnetically induced transparency resonance. Strong long-range interactions between Rydberg excitations give rise to a blockade between polaritons, resulting in large optical nonlinearities and modified polariton number statistics. By combining optical imaging and high-fidelity detection of the Rydberg polaritons we investigate both aspects of this coupled atom-light system. We map out the full nonlinear optical response as a function of atomic density and follow the temporal evolution of polaritons through the atomic cloud. In the blockade regime, the statistical fluctuations of the polariton number drop well below the quantum noise limit. The low level of fluctuations indicates that photon correlations modified by the strong interactions have a significant backaction on the Rydberg atom statistics. PMID:25167407
Microwave photon counter based on Josephson junctions.
Chen, Y-F; Hover, D; Sendelbach, S; Maurer, L; Merkel, S T; Pritchett, E J; Wilhelm, F K; McDermott, R
2011-11-18
We describe a microwave photon counter based on the current-biased Josephson junction. The junction is tuned to absorb single microwave photons from the incident field, after which it tunnels into a classically observable voltage state. Using two such detectors, we have performed a microwave version of the Hanbury Brown-Twiss experiment at 4 GHz and demonstrated a clear signature of photon bunching for a thermal source. The design is readily scalable to tens of parallelized junctions, a configuration that would allow number-resolved counting of microwave photons. PMID:22181922
Jaynes Cummings Photonic Superlattices
Stefano Longhi
2011-11-15
A classical realization of the Jaynes-Cummings (JC) model, describing the interaction of a two-level atom with a quantized cavity mode, is proposed based on light transport in engineered waveguide superlattices. The optical setting enables to visualize in Fock space dynamical regimes not yet accessible in quantum systems, providing new physical insights into the deep strong coupling regime of the JC model. In particular, bouncing of photon number wave packets in Hilbert space and revivals of populations are explained as generalized Bloch oscillations in an inhomogeneous tight-binding lattice.
Statistical Associates Publishing
NSDL National Science Digital Library
Garson, G. David
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.
Resonance formation in photon-photon collisions
Gidal, G.
1988-08-01
Recent experimental progress on resonance formation in photon-photon collisions is reviewed with particular emphasis on the pseudoscalar and tensor nonents and on the ..gamma gamma..* production of spin-one resonances. 37 refs., 17 figs., 5 tabs.
NASA Astrophysics Data System (ADS)
Wiersma, Diederik S.
2013-03-01
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.
Photon-counting techniques with silicon avalanche photodiodes
Henri Dautet; Pierre Deschamps; Bruno Dion; Andrew D. MacGregor; Darleene MacSween; Robert J. McIntyre; Claude Trottier; Paul P. Webb
1993-01-01
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).
Continuous-mode multi-photon filtering
Hongting Song; Guofeng Zhang; Zairong Xi
2014-09-29
The purpose of this paper is to derive filtering equations for an arbitrary open quantum system driven by a light wavepacket in a continuous-mode multi-photon state. A continuous-mode multi-photon state is a state of a travelling wavepacket that contains a definite number of photons and is characterised by a temporal (or spectral) profile. After the interaction with the system, the output light is measured by means of homodyne detection or photodetection. Filters for both cases are derived in this paper. Unlike the vacuum or the coherent case, the annihilation operator of the light field acting on a multi-photon state changes the state by annihilating a photon, which makes the traditional filtering techniques inapplicable. To circumvent this difficulty, we adopt a non-Markovian embedding technique proposed in [20]} for the study of single-photon filtering problem. However, the multi-photon nature of the problem makes the study more mathematically involved. Moreover, as illustrated by an example --- a two-level atom driven a continuous-mode two-photon state. Multi-photon filters can reveal interesting optical phenomena absent in either the single-photon filter case or the continuous-mode Fock state case.
NSDL National Science Digital Library
Grinstead, Charles M.
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.
Smith, Alwyn
1969-01-01
This paper is based on an analysis of questionnaires sent to the health ministries of Member States of WHO asking for information about the extent, nature, and scope of morbidity statistical information. It is clear that most countries collect some statistics of morbidity and many countries collect extensive data. However, few countries relate their collection to the needs of health administrators for information, and many countries collect statistics principally for publication in annual volumes which may appear anything up to 3 years after the year to which they refer. The desiderata of morbidity statistics may be summarized as reliability, representativeness, and relevance to current health problems. PMID:5306722
Precision measurements with photon-subtracted or photon-added Gaussian states
NASA Astrophysics Data System (ADS)
Braun, Daniel; Jian, Pu; Pinel, Olivier; Treps, Nicolas
2014-07-01
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.
Popper's experiment with randomly paired photons in thermal state
NASA Astrophysics Data System (ADS)
Peng, Tao; Simon, Jason; Chen, Hui; French, Robert; Shih, Yanhua
2015-01-01
We realized Popper's thought experiment via the photon number fluctuation correlation measurement of random paired photons in thermal state. The experiment produces the same results as that of Kim and Shih in 1998 with entangled photon pairs, which agreed with Popper's prediction. Although the observation cannot be considered as a violation of the uncertainty relation as Popper believed, this experiment reveals a concern about nonlocal interference of a random photon pair, which involves the superposition of multi-photon amplitudes, and multi-photon detection events at a distance.
Dai, Wu-Sheng, E-mail: daiwusheng@tju.edu.cn; Xie, Mi, E-mail: xiemi@tju.edu.cn
2013-05-15
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.
Supernova brightening from chameleon-photon mixing
Burrage, C. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, Cambridge, CB2 0WA (United Kingdom)
2008-02-15
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.
Lyapunov exponents for one-dimensional aperiodic photonic bandgap structures
NASA Astrophysics Data System (ADS)
Kissel, Glen J.
2011-10-01
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.
General displaced SU(1, 1) number states: Revisited
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
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.
A Very Low Latency Photonic Quantum Random Bit Generator for use in a Loophole Free Bell Test
Mario Stip?evi?
2014-07-17
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.
Multimode One-Way Waveguides of Large Chern Numbers
Skirlo, Scott A.
Current experimental realizations of the quantum anomalous Hall phase in both electronic and photonic systems have been limited to a Chern number of one. In photonics, this corresponds to a single-mode one-way edge waveguide. ...
ERIC Educational Resources Information Center
Petocz, Peter; Sowey, Eric
2008-01-01
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…
Recursive relations for processes with n photons of noncommutative QED
NASA Astrophysics Data System (ADS)
Jafari, Abolfazl
2007-10-01
Recursion relations are derived in the sense of Berends-Giele for the multi-photon processes of noncommutative QED. The relations concern purely photonic processes as well as the processes with two fermions involved, both for arbitrary number of photons at tree level. It is shown that despite of the dependence of noncommutative vertices on momentum, in contrast to momentum-independent color factors of QCD, the recursion relation method can be employed for multi-photon processes of noncommutative QED.
Aaron M. Hagerstrom; Thomas E. Murphy; Rajarshi Roy
2015-03-27
Some physical processes, including the intensity fluctuations of a chaotic laser, the detection of single photons, and the Brownian motion of a microscopic particle in a fluid are unpredictable, at least on long timescales. This unpredictability can be due to a variety of physical mechanisms, but it is quantified by an entropy rate. This rate describes how quickly a system produces new and random information, is fundamentally important in statistical mechanics and practically important for random number generation. We experimentally study entropy generation and the emergence of deterministic chaotic dynamics from discrete noise in a system that applies feedback to a weak optical signal at the single-photon level. We show that the dynamics qualitatively change from shot noise to chaos as the photon rate increases, and that the entropy rate can reflect either the deterministic or noisy aspects of the system depending on the sampling rate and resolution.
Photon-Photon Interactions via Rydberg Blockade
Alexey V. Gorshkov; Johannes Otterbach; Michael Fleischhauer; Thomas Pohl; Mikhail D. Lukin
2011-03-18
We develop the theory of light propagation under the conditions of electromagnetically induced transparency (EIT) 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 demonstrate 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 quantum gates, as well as for studying many-body phenomena with strongly correlated photons.
NASA Astrophysics Data System (ADS)
He, Cheng; Lin, Liang; Sun, Xiao-Chen; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng
2014-01-01
As exotic phenomena in optics, topological states in photonic crystals have drawn much attention due to their fundamental significance and great potential applications. Because of the broken time-reversal symmetry under the influence of an external magnetic field, the photonic crystals composed of magneto-optical materials will lead to the degeneracy lifting and show particular topological characters of energy bands. The upper and lower bulk bands have nonzero integer topological numbers. The gapless edge states can be realized to connect two bulk states. This topological photonic states originated from the topological property can be analogous to the integer quantum Hall effect in an electronic system. The gapless edge state only possesses a single sign of gradient in the whole Brillouin zone, and thus the group velocity is only in one direction leading to the one-way energy flow, which is robust to disorder and impurity due to the nontrivial topological nature of the corresponding electromagnetic states. Furthermore, this one-way edge state would cross the Brillouin center with nonzero group velocity, where the negative-zero-positive phase velocity can be used to realize some interesting phenomena such as tunneling and backward phase propagation. On the other hand, under the protection of time-reversal symmetry, a pair of gapless edge states can also be constructed by using magnetic-electric coupling meta-materials, exhibiting Fermion-like spin helix topological edge states, which can be regarded as an optical counterpart of topological insulator originating from the spin-orbit coupling. The aim of this article is to have a comprehensive review of recent research literatures published in this emerging field of photonic topological phenomena. Photonic topological states and their related phenomena are presented and analyzed, including the chiral edge states, polarization dependent transportation, unidirectional waveguide and nonreciprocal optical transmission, all of which might lead to novel applications such as one-way splitter, optical isolator and delay line. In addition, the possible prospect and development of related topics are also discussed.
Photon theory hypothesis about photon tunneling microscope's subwavelength resolution
NASA Astrophysics Data System (ADS)
Zhu, Yanbin; Ma, Junfu
1995-09-01
The foundation for the invention of the photon scanning tunneling microscope (PSTM) are the near field scanning optical microscope, the optical fiber technique, the total internal reflection, high sensitive opto-electronic detecting technique and computer technique etc. Recent research results show the subwavelength resolution of 1 - 3 nm is obtained. How to explain the PSTM has got such high subwavelength resolution? What value is the PSTM's limiting of subwavelength resolution? For resolving these problems this paper presented a photon theory hypothesis about PSTM that is based on the following two basic laws: (1) Photon is not only a carrier bringing energy and optical information, but also is a particle occupied fixed space size. (2) When a photon happened reflection, refraction, scattering, etc., only changed its energy and optical information carried, its particle size doesn't change. g (DOT) pphoton equals constant. Using these two basic laws to PSTM, the `evanescent field' is practically a weak photon distribution field and the detecting fiber tip diameter is practically a `gate' which size controlled the photon numbers into fiber tip. Passing through some calculation and inference, the following three conclusions can be given: (1) Under the PSTM's detection system sensitivity is high enough, the diameter D of detecting fiber tip and the near field detecting distance Z are the two most important factors to decide the subwavelength resolution of PSTM. (2) The limiting of PSTM's resolution will be given upon the conditions of D equals pphoton and Z equals pphoton, where pphoton is one photon size. (2) The final resolution limit R of PSTM will be lim R equals pphoton, D yields pphoton, Z yields pphoton.
First measurement of the quark-to-photon fragmentation function
Damir Buskulic; David William Casper; I. De Bonis; D. Decamp; P. Ghez; C. Goy; J.-P. Lees; A. Lucotte; M.-N. Minard; P. Odier; B. Pietrzyk; F. Ariztizabal; M. Chmeissani; J. M. Crespo; I. Efthymiopoulos; E. Fernandez; M. Fernandez-Bosman; V. Gaitan; Ll. Garrido; M. Martinez; S. Orteu; A. Pacheco; C. Padilla; Fabrizio Palla; A. Pascual; J. A. Perlas; F. Sanchez; F. Teubert; A. Colaleo; D. Creanza; M. de Palma; A. Farilla; G. Gelao; M. Girone; Giuseppe Iaselli; G. Maggi; M. Maggi; N. Marinelli; S. Natali; S. Nuzzo; A. Ranieri; G. Raso; F. Romano; F. Ruggieri; G. Selvaggi; L. Silvestris; P. Tempesta; G. Zito; X. Huang; J. Lin; Q. Ouyang; T. Wang; Y. Xie; R. Xu; S. Xue; J. Zhang; L. Zhang; W. Zhao; G. Bonvicini; M. Cattaneo; P. Comas; P. Coyle; H. Drevermann; A. Engelhardt; Roger W Forty; M. Frank; R. Hagelberg; J. Harvey; R. Jacobsen; P. Janot; B. Jost; J. Knobloch; Ivan Lehraus; C. Markou; E. B. Martin; P. Mato; H. Meinhard; Adolf G Minten; R. Miquel; T. Oest; P. Palazzi; J. R. Pater; J.-F. Pusztaszeri; F. Ranjard; P E Rensing; Luigi Rolandi; D. Schlatter; M. Schmelling; O. Schneider; W. Tejessy; I. R. Tomalin; A. Venturi; H W Wachsmuth; W. Wiedenmann; T. Wildish; W. Witzeling; J. Wotschack; Ziad J Ajaltouni; Maria Bardadin-Otwinowska; A. Barres; C. Boyer; A. Falvard; P. Gay; C. Guicheney; P. Henrard; J. Jousset; B. Michel; S. Monteil; J. C. Montret; D. Pallin; P. Perret; F. Podlyski; J. Proriol; J.-M. Rossignol; F. Saadi; Tom Fearnley; J. B. Hansen; J. D. Hansen; P. H. Hansen; B. S. Nilsson; A. Kyriakis; Errietta Simopoulou; I. Siotis; Anna Vayaki; K. Zachariadou; A. Blondel; G R Bonneaud; J. C. Brient; P. Bourdon; L. Passalacqua; A. Rougé; M. Rumpf; R. Tanaka; Andrea Valassi; M. Verderi; H L Videau; D. J. Candlin; M. I. Parsons; E. Focardi; G. Parrini; M. Corden; M C Delfino; C H Georgiopoulos; D. E. Jaffe; A. Antonelli; G. Bencivenni; G. Bologna; F. Bossi; P. Campana; G. Capon; V. Chiarella; G. Felici; P. Laurelli; G. Mannocchi; F. Murtas; G. P. Murtas; M. Pepe-Altarelli; S. J. Dorris; A. W. Halley; I. ten Have; I. G. Knowles; J. G. Lynch; W. T. Morton; V. O’Shea; C. Raine; P. Reeves; J. M. Scarr; K. Smith; M. G. Smith; A. S. Thompson; F. Thomson; S. Thorn; R. M. Turnbull; U. Becker; O. Braun; C. Geweniger; G. Graefe; P. Hanke; V. Hepp; E. E. Kluge; A. Putzer; B. Rensch; M. Schmidt; J. Sommer; H. Stenzel; K. Tittel; S. Werner; M. Wunsch; R. Beuselinck; David M Binnie; W. Cameron; D. J. Colling; Peter J Dornan; N P Konstantinidis; L. Moneta; A. Moutoussi; J. Nash; G. San Martin; J. K. Sedgbeer; A. M. Stacey; G. Dissertori; P. Girtler; E. Kneringer; D. Kuhn; G. Rudolph; C. K. Bowdery; T. J. Brodbeck; P. Colrain; G. Crawford; A. J. Finch; F. Foster; G. Hughes; Terence Sloan; E. P. Whelan; M. I. Williams; A. Galla; A. M. Greene; K. Kleinknecht; G. Quast; J. Raab; B. Renk; H.-G. Sander; R. Wanke; C. Zeitnitz; Jean-Jacques Aubert; A. M. Bencheikh; C. Bencheikh; C. Benchouk; A. Bonissent; G. Bujosa; D. Calvet; J. Carr; C. Diaconu; F. Etienne; M. Thulasidas; D. Nicod; P. Payre; D. Rousseau; M. Talby; I. Abt; R. Assmann; C. Bauer; W. Blum; D. Brown; H. Dietl; F. Dydak; G. Ganis; C. Gotzhein; K. Jakobs; H. Kroha; G. Lütjens; G. Lutz; W. Männer; H.-G. Moser; R. Richter; A. Rosado-Schlosser; S. Schael; R. Settles; H. Seywerd; U. Stierlin; R. St. Denis; G. Wolf; R. Alemany; J. Boucrot; O. Callot; A. Cordier; F. Courault; M. Davier; L. Duflot; J.-F. Grivaz; Ph Heusse; M. Jacquet; D. W. Kim; F. Le Diberder; J. Lefrançois; A.-M. Lutz; G. Musolino; I. Nikolic; H. J. Park; I. C. Park; M.-H. Schune; S. Simion; J.-J. Veillet; I. Videau; D. Abbaneo; P. Azzurri; G Batignani; G. Batignani; S. Bettarini; C. Bozzi; G. Calderini; M. Carpinelli; M. A. Ciocci; V. Ciulli; R. Dell’Orso; R. Fantechi; I. Ferrante; L. Foà; F. Forti; A. Giassi; M. A. Giorgi; A. Gregorio; F. Ligabue; A. Lusiani; P. S. Marrocchesi; A. Messineo; G. Rizzo; G. Sanguinetti; A. Sciabà; P. Spagnolo; J. Steinberger; R. Tenchini; G Triggiani; C. Vannini; P. G. Verdini; J. Walsh; A. P. Betteridge; G. A. Blair; L. M. Bryant; F. Cerutti; Y. Gao; M. G. Green; D. L. Johnson; T. Medcalf; L. M. Mir; P. Perrodo; J. A. Strong; V. Bertin; D. R. Botterill; R. W. Clifft; T. R. Edgecock; S. Haywood; M. Edwards; P. Maley; P. R. Norton; J. C. Thompson; B. Bloch-Devaux; P. Colas; H. Duarte; S. Emery; W. Kozanecki; E. Lançon; M. C. Lemaire; E. Locci; B. Marx; P. Perez; J F Renardy; A Roussarie; A. Roussarie; J Schwindling; D. Si Mohand; A. Trabelsi; B. Vallage; R. P. Johnson; H. Y. Kim; A. M. Litke; M. A. McNeil; G. Taylor; A. Beddall; C. N. Booth; R. Boswell; S. Cartwright; F. Combley; I. Dawson; A. Koksal; M. Letho; W. M. Newton; C. Rankin; L. F. Thompson; A. Böhrer; S. Brandt; G. Cowan; E. Feigl; C. Grupen; G. Lutters; J. Minguet-Rodriguez; F. Rivera; P. Saraiva; L. Smolik; F. Stephan; M. Apollonio; L. Bosisio; R. Della Marina
1995-01-01
Earlier measurements at LEP of isolated hard photons in hadronic Z decays, attributed to radiation from primary quark pairs,\\u000a have been extended in the ALEPH experiment to include hard photon productioninside hadron jets. Events are selected where all particles combine democratically to form hadron jets, one of which contains a\\u000a photon with a fractional energyz?0.7. After statistical subtraction of non-prompt
NSDL National Science Digital Library
Laurin Publishing
It's everything photonics! From the the publishers of Photonics Spectra magazine this website will help you gain technical and practical information for every aspect of the global industry, integrating all segments of photonics: optics, lasers, imaging, fiber optics, electro-optics as well as photonic component manufacturing.
PHOTONICS and DEVICE MICROFABRICATION
Mottram, Nigel
MSc/PgDip PHOTONICS and DEVICE MICROFABRICATION #12;MSc/PgDip PHOTONICS and DEVICE MICROFABRICATION and analyse micro-/nano-scale photonic and optoelectronic devices, underpinned by transferrable skills device fabrication facilities. The Institute of Photonics is a commercially- oriented research unit
Photonics: An Enabling Technology
NSDL National Science Digital Library
This two-page PDF, presented by the National Center for Optics and Photonics Education (OP-TEC), provides an overview of photonics, including what it is, why it's important, workforce demand for photonics technicians, the various photonics-related fields, and about the OP-TEC program.
Photon position eigenvectors lead to complete photon wave mechanics
Margaret Hawton
2007-11-01
We have recently constructed a photon position operator with commuting components. This was long thought to be impossible, but our position eigenvectors have a vortex structure like twisted light. Thus they are not spherically symmetric and the position operator does not transform as a vector, so that previous non-existence arguments do not apply. We find two classes of position eigenvectors and obtain photon wave functions by projection onto the bases of position eigenkets that they define, following the usual rules of quantum mechanics. The hermitian position operator, r0, leads to a Landau-Peierls wave function, while field-like eigenvectors of the nonhermitian position operator and its adjoint lead to a biorthonormal basis. These two bases are equivalent in the sense that they are related by a similarity transformation. The eigenvectors of the nonhermitian position operators lead to a field-potential wave function pair. These field-like positive frequency wave functions satisfy Maxwell's equations, and thus justify the supposition that MEs describe single photon wave mechanics. The expectation value of the number operator is photon density with undetected photons integrated over, consistent with Feynman's conclusion that the density of non-interacting particles can be interpreted as probability density.
Klaus Reygers; for the PHENIX Collaboration
2009-08-17
A brief overview of direct-photon measurements in p+p and Au+Au collisions at sqrt(s_NN) = 200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) is given. Direct-photon yields for pT > 4 GeV/c and photon-hadron azimuthal correlations were determined with the aid of an electromagnetic calorimeter. By detecting e+e- pairs from the internal conversion of virtual photons direct-photon yields were measured between 1 photons from a quark-gluon plasma (QGP) are expected to contribute significantly to the total direct-photon yield in this range.
Transitioning from micro to nano-photonics with Photonic Crystal Fibers Maksim Skorobogatiy
Skorobogatiy, Maksim
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
UK photonics in defence and security
NASA Astrophysics Data System (ADS)
Gracie, C.; Tooley, I.; Wilson, A.
2008-10-01
The UK is globally recognised as strong in Photonics. However its Photonics sector is fragmented and the size and sectors of interest have not previously been established. The UK government has instigated the formation of the Photonics Knowledge Transfer Network (PKTN) to bring the Photonics community together. The UK features in Defence & Security; Communications; Measurement; Medical Technology; Lighting; Solar Energy; Information Technology and Flat Panels. This expertise is scattered through out the UK in geographic areas each with a breadth of Photonic interests. The PKTN has mapped the UK capability in all Photonics sectors. This paper will present the capability of the Companies, Research Institutions and Infrastructure making up the Defence & Security Photonics scene in the UK. Large Defence companies in the UK are well known throughout the world. However, there are a large number of SMEs, which may not be as well known in the supply chain. These are being actively encouraged by the UK MoD to engage with the Defence & Security Market and shall be discussed here. The presentation will reference a number of organisations which help to fund and network the community, such as the Defence Technology Centres. In addition the Roadmap for Defence & Security in the UK, produced for the UK Photonics Strategy (July 2006) by the Scottish Optoelectronics Association will be described and the plans in taking it forward under the PKTN will be revealed.
NASA Technical Reports Server (NTRS)
Feiveson, Alan H.; Foy, Millennia; Ploutz-Snyder, Robert; Fiedler, James
2014-01-01
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.
Michele Arzano; Dario Benedetti
2008-09-04
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.
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.
Graded photonic quasicrystals.
Dyachenko, Pavel N; Pavelyev, Vladimir S; Soifer, Victor A
2012-06-15
We introduce graded photonic quasicrystals and investigate properties of such structures on the example of a Luneburg lens based on a dodecagonal photonic quasicrystal. It is shown that the graded photonic quasicrystal lens has better focusing properties as compared with the graded photonic crystal lens in a frequency range suitable for experimental realization. The proposed graded photonic quasicrystals can be used in optical systems where compact and powerful focusing elements are required. PMID:22739847
Statistics of stable marriages
NASA Astrophysics Data System (ADS)
Dzierzawa, Michael; Oméro, Marie-José
2000-11-01
In the stable marriage problem N men and N women have to be matched by pairs under the constraint that the resulting matching is stable. We study the statistical properties of stable matchings in the large N limit using both numerical and analytical methods. Generalizations of the model including singles and unequal numbers of men and women are also investigated.
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.
Introductory Statistics First midterm
D'Orsogna, Maria Rita
Math 140 Introductory Statistics First midterm February 20 2010 #12;Box Plots Graphical display = 70 Pig = 11 Squirrel = 12 Lion = 50 #12;Modified box plot Graphical display of 5 number summary Q1, Q2, Q3, max, min and outliers Modified box plot #12;Box plots Box Plots are useful when Plotting
Photon-Photon Collisions -- Past and Future
Brodsky, Stanley J.; /SLAC
2005-12-02
I give a brief review of the history of photon-photon physics and a survey of its potential at future electron-positron colliders. Exclusive hadron production processes in photon-photon and electron-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes. There are also important high energy {gamma}{gamma} and e{gamma} tests of quantum chromodynamics, including the production of jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Since photons couple directly to all fundamental fields carrying the electromagnetic current including leptons, quarks, W's and supersymmetric particles, high energy {gamma}{gamma} collisions will provide a comprehensive laboratory for Higgs production and exploring virtually every aspect of the Standard Model and its extensions. High energy back-scattered laser beams will thus greatly extend the range of physics of the International Linear Collider.
Notoph-Graviton-Photon Coupling
Valeriy V. Dvoeglazov
2014-11-16
In the sixties Ogievetskii and Polubarinov proposed the concept of a notoph, whose helicity properties are complementary to those of a photon. Later, Kalb and Ramond (and others) developed this theoretical concept. And, at the present times it is widely accepted. We analyze the quantum theory of antisymmetric tensor fields with taking into account mass dimensions of notoph and photon. It appears to be possible to describe both photon and notoph degrees of freedom on the basis of the modified Bargmann-Wigner formalism for the symmetric second-rank spinor. Next, we proceed to derive equations for the symmetric tensor of the second rank on the basis of the Bargmann-Wigner formalism in a straightforward way. The symmetric multispinor of the fourth rank is used. It is constructed out of the Dirac 4-spinors. Due to serious problems with the interpretation of the results obtained on using the standard procedure we generalize it and obtain the spin-2 relativistic equations, which are consistent with the general relativity. The importance of the 4-vector field (and its gauge part) is pointed out. Thus, we present the full theory which contains photon, notoph (the Kalb-Ramond field) and the graviton. The relations of this theory with the higher spin theories are established. In fact, we deduced the gravitational field equations from relativistic quantum mechanics. We estimate possible interactions, fermion-notoph, graviton-notoph, photon-notoph. PACS number: 03.65.Pm, 04.50.-h, 11.30.Cp
NSDL National Science Digital Library
Dudley, Richard
Created by Richard Dudley of the Massachusetts Institute of Technology, this lesson, Mathematical Statistics, is a graduate-level course featuring book chapters and sections presented as lecture notes, problem sets, exams, and a description for an optional term-paper. The course covers: decision theory, estimation, confidence intervals, hypothesis testing, asymptotic efficiency of estimates, exponential families, sequential analysis, and large sample theory. This is a comprehensive overview of this upper level statistics course.
V. Jaksi ´; C.-A. Pillet
1937-01-01
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
Web Pages That Perform Statistical Calculations: Interactive Statistical Calculation Pages
NSDL National Science Digital Library
John Pezullo, Associate Professor of Pharmacology and Biostatistics at Georgetown University, has helped compile this monstrous metasite of freely accessible multi-platform statistical software. With links to pages around the world, the table of contents includes access to calculators, plotters, random number generators, and programs that perform literally hundreds of calculations. Hosted by America Online, the site also includes links to online statistics books, tutorials, and downloadable software. This is a virtual treasure trove of statistical calculation pages for mathematicians and statisticians.
Photon-photon scattering: a tutorial
Yi Liang; Andrzej Czarnecki
2011-12-08
Long-established results for the low-energy photon-photon scattering, gamma gamma --> gamma gamma, have recently been questioned. We analyze that claim and demonstrate that it is inconsistent with experience. We demonstrate that the mistake originates from an erroneous manipulation of divergent integrals and discuss the connection with another recent claim about the Higgs decay into two photons. We show a simple way of correctly computing the low-energy gamma gamma scattering.
NASA Astrophysics Data System (ADS)
Habs, D.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.
2012-07-01
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.
Teleporting photonic qudits using multimode quantum scissors.
Goyal, Sandeep K; Konrad, Thomas
2013-01-01
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
Large numbers hypothesis. II - Electromagnetic radiation
NASA Technical Reports Server (NTRS)
Adams, P. J.
1983-01-01
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.
Photonic Molecules and Spectral Engineering
Boriskina, Svetlana V.
2010-01-01
This chapter reviews the fundamental optical properties and applications of photonic molecules (PMs) – photonic structures formed by electromagnetic coupling of two or more optical microcavities (photonic atoms). Controllable ...
ERIC Educational Resources Information Center
Lynch, Mary Jo; Oder, Norman; Halstead, Kent; Fox, Bette-Lee
2003-01-01
Includes seven reports that discuss research on libraries and librarianship, including academic, public, and school libraries; awards and grants; number of libraries in the United States and Canada; National Center for Education Statistics results; library expenditures for public, academic, special, and government libraries; library budgets; price…
Modern Statistical Methods for GLAST Event Analysis
Robin D. Morris; Johann Cohen-Tanugi
2007-03-28
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.
SOCR: Statistics Online Computational Resource
ERIC Educational Resources Information Center
Dinov, Ivo D.
2006-01-01
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…
NSDL National Science Digital Library
2014-01-01
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.
Collective two-particle resonances induced by photon entanglement
Richter, Marten [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States); Institut fuer Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)
2011-06-15
An assembly of noninteracting atoms may become correlated upon interaction with entangled photons, and certain elements of their joint density matrix can then show collective resonances. We explore experimental signatures of these resonances in the nonlinear response of a pair of two-level atoms. We find that these resonances are canceled out in stimulated signals such as pump-probe and two-photon absorption due to the destructive interference of two-photon-absorption and emission pathways in the joint two-particle space. However, they may be observed in photon statistics (Hanbury-Brown-Twiss) measurements through the attenuation of two-time intensity correlations.
NSDL National Science Digital Library
2008-01-01
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!
Topological Invariants in Point Group Symmetric Photonic Topological Insulators
Chen, Xiao-Dong; Chen, Wen-Jie; Wang, Jia-Rong; Dong, Jian-Wen
2014-01-01
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.
Nonabsorbing high-efficiency counter for itinerant microwave photons
NASA Astrophysics Data System (ADS)
Fan, Bixuan; Johansson, Göran; Combes, Joshua; Milburn, G. J.; Stace, Thomas M.
2014-07-01
Detecting an itinerant microwave photon with high efficiency is an outstanding problem in microwave photonics and its applications. We present a scheme to detect an itinerant microwave photon in a transmission line via the nonlinearity provided by a transmon in a driven microwave resonator. With a single transmon we achieve 84% distinguishability between zero and one microwave photons and 90% distinguishability with two cascaded transmons by performing continuous measurements on the output field of the resonator. We also show how the measurement diminishes coherence in the photon number basis thereby illustrating a fundamental principle of quantum measurement: The decoherence rate increases as the detector is made more effective.
A Diamond Nanowire Single Photon Antenna
Tom Babinec; Birgit J. M. Hausmann; Mughees Khan; Yinan Zhang; Jero Maze; Philip R. Hemmer; Marko Loncar
2009-10-28
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.
Heavy flavor production from photons and hadrons
Heusch, C.A.
1982-01-01
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)
High energy photon-photon collisions
Brodsky, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
1994-07-01
The collisions of high energy photons produced at a electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions and extensions of the standard model. The luminosity and energy of the colliding photons produced by back-scattering laser beams is expected to be comparable to that of the primary e{sup +}e{sup {minus}} collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly {gamma}{gamma} {yields} W{sup +}W{sup {minus}}, {gamma}{gamma} {yields} Higgs bosons, and higher-order loop processes, such as {gamma}{gamma} {yields} {gamma}{gamma}, Z{gamma} and ZZ. Since each photon can be resolved into a W{sup +}W{sup minus} pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. We also review high energy {gamma}{gamma} tests of quantum chromodynamics, such as the scaling of the photon structure function, t{bar t} production, mini-jet processes, and diffractive reactions.
Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)
2004-07-27
A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.
NSDL National Science Digital Library
Clarity Innovations, Inc.
2013-11-22
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.
Composite Photon Theory Versus Elementary Photon Theory
Walton A. Perkins
2015-03-02
The purpose of this paper is to show that the composite photon theory measures up well against the Standard Model's elementary photon theory. This is done by comparing the two theories area by area. Although the predictions of quantum electrodynamics are in excellent agreement with experiment (as in the anomalous magnetic moment of the electron), there are some problems, such as the difficulty in describing the electromagnetic field with the four-component vector potential because the photon has only two polarization states. In most areas the two theories give similar results, so it is impossible to rule out the composite photon theory. Pryce's arguments in 1938 against a composite photon theory are shown to be invalid or irrelevant. Recently, it has been realized that in the composite theory the antiphoton does not interact with matter because it is formed of a neutrino and an antineutrino with the wrong helicity. This leads to experimental tests that can determine which theory is correct.
NSDL National Science Digital Library
TERC
2010-01-01
Combine logic and numbers in this game for all ages. 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 and in Spanish.
... which people are catching the flu, the average cost of a medical procedure. These are all types of ... statistics to see patterns of diseases in groups of people. This can help in ... ways to control diseases and deciding which diseases should be studied.
NSDL National Science Digital Library
2013-01-01
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.
Peter Gacs; John Tromp; Paul Vitanyi
2001-01-01
While Kolmogorov (1965, 1983) complexity is the accepted absolute measure of information content of an individual finite object, a similarly absolute notion is needed for the relation between an individual data sample and an individual model summarizing the information in the data, for example, a finite set (or probability distribution) where the data sample typically came from. The statistical theory
Péter Gács; John Tromp; Paul M. B. Vitányi
2001-01-01
While Kolmogorov complexity is the accepted absolute measure of information content of an individual finite object, a similarly absolute notion is needed for the relation between an individual data sample and an individual model summarizing the information in the data, for example, a finite set (or probability distribution) where the data sample typically came from. The statistical theory based on
NSDL National Science Digital Library
Annis, Charles
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.
STATISTICS GROUP :: WEEK #1 Jordan Webster 19 October 2011 1 #12;19 October 2011 2 19 October 2011(x|, x0) = 1 /2 2/2+(x-x0)2 divergent divergent mass of resonance Table 1: some basic info for commonly
NSDL National Science Digital Library
Anderson-Cook, C.
This is a collection of applets regarding various topics in statistics. Topics include central limit theorem, probability distributions, hypothesis testing, power, confidence intervals, correlation, control charts, experimental design, data analysis, and regression. Each topic has a description page and links to one or more applets.
Wei Li; Yong Zhao; Ruizhen Cui; Haitao Zhang
2009-01-01
Plasma photonic crystals are presented in this paper. A plasma photonic crystal can control the propagation of electromagnetic\\u000a waves. Similar to other photonic crystals, the permittivity of a plasma photonic crystal is distributed as periodic arrays.\\u000a The properties of periodic arrays of plasma can broaden the range of frequency and enhance the efficiency of beam-wave interaction.\\u000a In special uses, the
ERIC Educational Resources Information Center
Crawford, David
1997-01-01
Presents three number games for mathematics classrooms designed to improve the learning of number concepts. Game topics include determining products, arranging mathematical signs, and factoring. (ASK)
Homogeneous immunoassays by using photon burst counting technique of single gold nanoparticles.
Lan, Tao; Wang, Jinjie; Dong, Chaoqing; Huang, Xiangyi; Ren, Jicun
2015-01-01
In this paper, we reported a sensitive single particle method by combining the photon burst counting technique with gold nanoparticles (GNPs) as labeling probes. The photon bursting of single GNPs will be generated in a highly focused laser beam (less than 1 fL) due to the plasmon resonance scattering and Brownian motion of GNPs. We observed an excellent linear relationship between the photon burst counts and the number of particles in GNPs solution. We investigated the statistical behaviors of background noise and photon burst signal of GNPs, and proposed the data processing method based on Gaussian distribution of the background noise. A new homogeneous sandwich immunoassay was developed by using this single particle method. We evaluated the performance of this method by using prostate-specific antigen (PSA) as a model. The linear range of PSA was 1-1000 pmol/L and the detection limit was 0.8 pmol/L. This novel method was successfully used for the direct detection of cancer biomarker PSA in human serum samples. Our results were in good agreement with conventional ELISA assays. PMID:25476367
Two-photon imaging and spectroscopy of fresh human colon biopsies
NASA Astrophysics Data System (ADS)
Cicchi, R.; Sturiale, A.; Nesi, G.; Tonelli, F.; Pavone, F. S.
2012-03-01
Two-photon fluorescence (TPEF) microscopy is a powerful tool to image human tissues up to 200 microns depth without any exogenously added probe. TPEF can take advantage of the autofluorescence of molecules intrinsically contained in a biological tissue, as such NADH, elastin, collagen, and flavins. Two-photon microscopy has been already successfully used to image several types of tissues, including skin, muscles, tendons, bladder. Nevertheless, its usefulness in imaging colon tissue has not been deeply investigated yet. In this work we have used combined two-photon excited fluorescence (TPEF), second harmonic generation microscopy (SHG), fluorescence lifetime imaging microscopy (FLIM), and multispectral two-photon emission detection (MTPE) to investigate different kinds of human ex-vivo fresh biopsies of colon. Morphological and spectroscopic analyses allowed to characterize both healthy mucosa, polyp, and colon samples in a good agreement with common routine histology. Even if further analysis, as well as a more significant statistics on a large number of samples would be helpful to discriminate between low, mild, and high grade cancer, our method is a promising tool to be used as diagnostic confirmation of histological results, as well as a diagnostic tool in a multiphoton endoscope or colonoscope to be used in in-vivo imaging applications.
Bayesian reconstruction of photon interaction sequences for high-resolution PET detectors
Pratx, Guillem
2013-01-01
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
D. Peressounko; Y. Kharlov; for the ALICE collaboration
2009-09-17
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.
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
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.
Digest of Education Statistics 2001
NSDL National Science Digital Library
2002-01-01
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).
Means and method for calibrating a photon detector utilizing electron-photon coincidence
NASA Technical Reports Server (NTRS)
Srivastava, S. K. (inventor)
1984-01-01
An arrangement for calibrating a photon detector particularly applicable for the ultraviolet and vacuum ultraviolet regions is based on electron photon coincidence utilizing crossed electron beam atom beam collisions. Atoms are excited by electrons which lose a known amount of energy and scatter with a known remaining energy, while the excited atoms emit photons of known radiation. Electrons of the known remaining energy are separated from other electrons and are counted. Photons emitted in a direction related to the particular direction of scattered electrons are detected to serve as a standard. Each of the electrons is used to initiate the measurements of a time interval which terminates with the arrival of a photon exciting the photon detector. Only the number of time intervals related to the coincidence correlation and of electrons scattered in the particular direction with the known remaining energy and photons of a particular radiation level emitted due to the collisions of such scattered electrons are counted. The detector calibration is related to the number of counted electrons and photons.
Single Photon Transistor Mediated by Inter-State Rydberg Interaction
Hannes Gorniaczyk; Christoph Tresp; Johannes Schmidt; Helmut Fedder; Sebastian Hofferberth
2014-04-24
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 10 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).
NASA Astrophysics Data System (ADS)
Sridharan, Deepak
Over the last decade, exponential increase of information bandwidth over the internet and other communication media has increased the total power consumed by the devices associated with information exchange. With ever increasing number of users, and packing of a higher number of devices onto a chip, there is a great need for reduction in not only the power consumption of the devices but also the costs associated with information transfer. Currently, the benchmark in the energy consumption per logic operation is at femtojoule level and is set by the CMOS industry. However, optical devices based on single photon emitters coupled to a microcavity have the potential to reduce the optical power dissipation down to attojoule levels wherein only few 10s of photons are consumed for a logic operation. This work presents our theoretical and experimental efforts towards realization of all optical device based on the enhanced nonlinearities of a single photon emitter in a photonic crystal cavity. We show that a single quantum dot coupled to a photonic crystal cavity can be used to route an incoming optical beam with optical power dissipation of 14 attojoules, corresponding to only 65 photons. This value is well below the operational level for current CMOS devices indicating the potential for chip based optical transistors for reduction in energy consumption. The single photon emitters that we use to create the nonlinearity are the quantum dots, which are semiconductor nanostructures that exhibit a discrete energy spectrum. The interaction of the quantum dot, with light confined inside a photonic crystal cavity, results in strong atom-photon interactions which can be used for ultra-low power all optical switching. The strong interactions between a quantum dot and photonic crystal cavity can be further utilized to realize quantum computation schemes on a chip. I also describe techniques for integrating this transistor into an optical circuit, and discuss methods for post fabrication tuning to make reconfigurable active photonic devices that implement optical data processing at low light levels.
The Photon Underproduction Crisis
NASA Astrophysics Data System (ADS)
Kollmeier, Juna A.; Weinberg, David H.; Oppenheimer, Benjamin D.; Haardt, Francesco; Katz, Neal; Davé, Romeel; Fardal, Mark; Madau, Piero; Danforth, Charles; Ford, Amanda B.; Peeples, Molly S.; McEwen, Joseph
2014-07-01
We examine the statistics of the low-redshift Ly? forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background (UVB) and recent observations from the Cosmic Origins Spectrograph (COS). We find that the value of the metagalactic photoionization rate (?HI) required by our simulations to match the observed properties of the low-redshift Ly? forest is a factor of five larger than the value predicted by state-of-the art models for the evolution of this quantity. This mismatch in ?HI results in the mean flux decrement of the Ly? forest being overpredicted by at least a factor of two (a 10? discrepancy with observations) and a column density distribution of Ly? forest absorbers systematically and significantly elevated compared to observations over nearly two decades in column density. We examine potential resolutions to this mismatch and find that either conventional sources of ionizing photons (galaxies and quasars) must contribute considerably more than current observational estimates or our theoretical understanding of the low-redshift universe is in need of substantial revision.
Changliang Ren; Holger F. Hofmann
2011-06-01
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.
Optomechanical photon shuttling between photonic cavities
Huan Li; Mo Li
2014-09-03
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.
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.
NSDL National Science Digital Library
2012-01-01
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.
Learning Statistics By Doing Statistics
NSDL National Science Digital Library
Smith, Gary
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.
L. B. Okun
2006-02-13
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.
NASA Astrophysics Data System (ADS)
Gronberg, Jeffrey
2015-02-01
The idea of converting an electron linear collider into a photon-photon collider through the addition of high power lasers was put forward in the early 1980s. Progress in the field of high average power, short pulse lasers has brought the state of the art within striking range of what would be required to realize a photon collider. In parallel, the necessary modifications to the detector and accelerator to enable a photon collider have been laid out. The basic concept of the photon collider, the requirements for the laser, and the detector and accelerator impact are reviewed in this article.
Photon correlation holography.
Naik, Dinesh N; Singh, Rakesh Kumar; Ezawa, Takahiro; Miyamoto, Yoko; Takeda, Mitsuo
2011-01-17
Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light. PMID:21263682
Multiple photon emission in heavy particle decays
NASA Technical Reports Server (NTRS)
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
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.
NSDL National Science Digital Library
Mitchell Mark
2013-03-10
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.
NSDL National Science Digital Library
2013-12-04
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.
Direct generation of photon triplets using cascaded photon-pair sources
H. Hübel; D. R. Hamel; A. Fedrizzi; S. Ramelow; K. J. Resch; T. Jennewein
2010-07-28
Non-classical states of light, such as entangled photon pairs and number states, are essential for fundamental tests of quantum mechanics and optical quantum technologies. The most widespread technique for creating these quantum resources is the spontaneous parametric down-conversion (SPDC) of laser light into photon pairs. Conservation of energy and momentum in this process, known as phase-matching, gives rise to strong correlations which are used to produce two-photon entanglement in various degrees of freedom. It has been a longstanding goal of the quantum optics community to realise a source that can produce analogous correlations in photon triplets, but of the many approaches considered, none have been technically feasible. In this paper we report the observation of photon triplets generated by cascaded down-conversion. Here each triplet originates from a single pump photon, and therefore quantum correlations will extend over all three photons in a way not achievable with independently created photon pairs. We expect our photon-triplet source to open up new avenues of quantum optics and become an important tool in quantum technologies. Our source will allow experimental interrogation of novel quantum correlations, the post-selection free generation of tripartite entanglement without post- selection and the generation of heralded entangled-photon pairs suitable for linear optical quantum computing. Two of the triplet photons have a wavelength matched for optimal transmission in optical fibres, ideally suited for three-party quantum communication. Furthermore, our results open interesting regimes of non-linear optics, as we observe spontaneous down-conversion pumped by single photons, an interaction also highly relevant to optical quantum computing.
NSDL National Science Digital Library
2013-06-21
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.
NSDL National Science Digital Library
NRICH
2013-01-01
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.
NASA Astrophysics Data System (ADS)
Goodman, Joseph W.
2000-07-01
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
NASA Astrophysics Data System (ADS)
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
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.
Albano Farias, L.; Stephany, J. [Departamento de Fisica, Seccion de Fenomenos Opticos, Universidad Simon Bolivar, Apartado Postal 89000, Caracas 1080A (Venezuela, Bolivarian Republic of)
2010-12-15
We analyze the statistics of observables in continuous-variable (CV) quantum teleportation in the formalism of the characteristic function. We derive expressions for average values of output-state observables, in particular, cumulants which are additive in terms of the input state and the resource of teleportation. Working with a general class of teleportation resources, the squeezed-bell-like states, which may be optimized in a free parameter for better teleportation performance, we discuss the relation between resources optimal for fidelity and those optimal for different observable averages. We obtain the values of the free parameter of the squeezed-bell-like states which optimize the central momenta and cumulants up to fourth order. For the cumulants the distortion between in and out states due to teleportation depends only on the resource. We obtain optimal parameters {Delta}{sub (2)}{sup opt} and {Delta}{sub (4)}{sup opt} for the second- and fourth-order cumulants, which do not depend on the squeezing of the resource. The second-order central momenta, which are equal to the second-order cumulants, and the photon number average are also optimized by the resource with {Delta}{sub (2)}{sup opt}. We show that the optimal fidelity resource, which has been found previously to depend on the characteristics of input, approaches for high squeezing to the resource that optimizes the second-order momenta. A similar behavior is obtained for the resource that optimizes the photon statistics, which is treated here using the sum of the squared differences in photon probabilities of input versus output states as the distortion measure. This is interpreted naturally to mean that the distortions associated with second-order momenta dominate the behavior of the output state for large squeezing of the resource. Optimal fidelity resources and optimal photon statistics resources are compared, and it is shown that for mixtures of Fock states both resources are equivalent.
Photonic Doppler Velocimetry Multiplexing Techniques: Evaluation of Photonic Techniques
Edward Daykin
2012-05-24
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.
Qudit-Teleportation for photons with linear optics
Goyal, Sandeep K.; Boukama-Dzoussi, Patricia E.; Ghosh, Sibasish; Roux, Filippus S.; Konrad, Thomas
2014-01-01
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
Peinke, Joachim
Deterministic and Random Influences on the Statistics of the Foreign Exchange Market R. Friedrich Institute fÃ¼r Theoretische Physik, UniversitÃ¤t Stuttgart, D-70550 Stuttgart, Germany J. Peinke and Ch. Renner Fachbereich 8 Physik, UniversitÃ¤t Oldenburg, D-26111 Oldenburg, Germany (Received 19 January 1999; revised manuscript
Ross, Shane
of Asteroid Escape Rates Charles Jaffé,1,2,3 Shane D. Ross,1,2 Martin W. Lo,1,2 Jerrold Marsden,1 David to regulate the rate of escape of asteroids temporarily captured in circumplanetary orbits. The transition a statistical semianalytical theory for the rate of escape of asteroids temporarily captured by Mars. Theory
NSDL National Science Digital Library
Miss.Cochran
2008-03-26
You will be working with numbers in all sorts of ways. First, you will play cop by picking numbers based on their divisibility. Then you will be adding and subtracting fractions in two fun and exciting games. First, as a cop, you will catch numbers that are divisible by which ever number you pick, avoinding crashing into non-divisible numbers. Number Cop-Divisibility Now, play Fishy Fractions! and help feed the seagull by practicing adding fractions. Make sure you read the instructions before getting started! Make sure to simplify your answers! After you ...
State-dependent photon blockade via quantum-reservoir engineering
Adam Miranowicz; Jiri Bajer; Malgorzata Paprzycka; Yu-xi Liu; Alexandre M. Zagoskin; Franco Nori
2014-09-20
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.
U. S. Teenage Pregnancy Statistics
NSDL National Science Digital Library
The Alan Guttmacher Institute (AGI) is a nonpartisan organization that provides research, policy analysis, and public education about reproductive health. Recently, the AGI posted this special statistical report on teenage pregnancy in the US. The report consists of two large data tables synthesizing pregnancy statistics from 1972 to 1996. The first table provides the number of births, number of legal abortions, number of estimated miscarriages, and total number of pregnancies in the US between 1972 and 1996 for five different age distributions: fourteen or younger, fifteen to seventeen, eighteen to nineteen, fifteen to nineteen, and under twenty. The second table provides birth rates, abortion rates, and pregnancy rates per 1,000 women for the same years and age distributions as the first table. For both tables, data refer to the age of the women at time of pregnancy outcome, not at the time of conception. A list of statistical sources are included.
... 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 ...
NSDL National Science Digital Library
2011-10-13
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.
NSDL National Science Digital Library
2010-04-01
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.
J. Mark Heinzle; Claes Uggla
2012-12-21
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.
NSDL National Science Digital Library
Ms. Simpson
2007-10-27
Students will practice counting to 100, making numbers with base ten blocks and practicing ordinal numbers! Math is FUN! Lets have fun practicing counting to 100 ! Click when you are ready!Counting Now that you have practiced counting to 100, lets use the base ten blocks to make the number that is on the screen. Click when you are ready!Working with Base Ten Blocks We have now practiced counting and making numbers, lets ...
Statistical mechanics of nonlinear elasticity Oliver Penrose
Penrose, Oliver
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
Quick statistics Survey 55563 'Privacy Survey'
Kaiser, Gail E.
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
ANTHROPOLOGICAL STATISTICS I THE UNIVERSITY OF TENNESSEE
Auerbach, Benjamin M.
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
M. R. Schroeder
1989-01-01
Number theory, an abstract branch of mathematics that deals with relationships between whole numbers, has provided highly useful answers to numerous real-world problems. The author briefly reviews earlier uses of number theory and then examines recent applications to music, cryptography, and error-correction codes
Photon blockade in circuit quantum electrodynamics
NASA Astrophysics Data System (ADS)
Hoffman, Anthony; Srinivasan, Srikanth; Shim, Beumseok; Houck, Andrew
2010-03-01
Strong photon-photon interactions arise in a cavity strongly coupled to an atom or qubit, resulting in blockaded transmission[1]. In such a system, the resonant frequency of the cavity shifts with the presence of a single photon due to the strong number-dependent nature of the cavity nonlinearity. Here, we investigate the photon blockade regime in superconducting circuits with integrated transmon qubits. To maximize the nonlinear effects, both the cavity Q and qubit-cavity coupling are made extremely large by design, with Q exceeding 100,000. Cavity transmission is characterized using a microwave generator with a controllable output bandwidth. Measurements of transmitted power and spectra versus incident center frequency and bandwidth are presented. [1] K.M. Birnbaum et al., Nature, 436, 87 (2005).
Double Periodic Photonic Crystal with Metamaterial
NASA Astrophysics Data System (ADS)
Xiao, Zhong Yin; Wang, Zi Hua
2006-03-01
In this paper, the reflection and transmission coefficients of multi-layer dielectric and metamaterial media are derived by transmission-line method. Then, it is applied to double periodic photonic crystal structure, which is composed of two thin dielectric layers sandwiched by two thin metamaterial layers. The results show the structure has a large passband and a monotonous symmetric rising band edges compared with that for a conventional photonic crystal structure. If a defect layer is introduced, the localized modes appear. Furthermore, the number of transmission peaks in the photonic crystal structure can be tuned by changing the thickness of the defect in the structure. This photonic crystal may find application to broadband reflectors and the multi-wavelength narrow band optical filters.
NSDL National Science Digital Library
The World of Numbers is "an amalgamation of randomly gathered numbers, curios, puzzles, palindromes, primes, gems, your much valued contributions and more general information." Choosing "number palindromes" from the drop-down menu will take you to a page with a list of links to webpages on palindromes -- numbers that read the same from left to right as from right to left. Also posted are more examples of square palindromes, circular primes, Palindromic Primes, Palindromic Tetrahedra, and much more. Visitors are invited to make their comments and contributions as well. Also provided are links to websites on integers and other special numbers, such as primes and zero.
NSDL National Science Digital Library
Dan Bunker
2005-01-01
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.
Photons with Momentum Along Curved Paths
NASA Astrophysics Data System (ADS)
Davis, Basil S.
Electromagnetic energy flow is expressed mathematically by the Poynting Vector. Quantum theory determines that the Poynting Vector provides the direction of movement of the photons which are the quanta of the electromagnetic field. In this dissertation important phenomena featuring the flow of electromagnetic energy—and hence transport of photons—along curved paths are investigated. A circuit is considered in the shape of a ring, with a battery of negligible size and a wire of uniform resistance. A linear charge distribution in the wire generates an electrostatic field and a steady current through the circuit which maintains a constant magnetic field. Earlier studies of the Poynting vector and the rate of flow of energy considered only idealized geometries in which the Poynting vector was confined to the space within the circuit. But in more realistic cases the Poynting vector is nonzero outside as well as inside the circuit. An expression is obtained for the Poynting vector in terms of products of integrals, which are evaluated numerically to show the energy flow. Limiting expressions are obtained analytically. It is shown that the total power generated by the battery equals the energy flowing into the wire per unit time. Whereas the Poynting Vector flows along the direction of propagation of a plane wave photon, it is a different matter with photons described by Laguerre-Gaussian transverse profiles. Such "twisted" photon beams have a spiraling Poynting Vector that generates an orbital angular momentum that is distinct from the photon's spin angular momentum. The transverse confinement of the twisted photon beam gives rise to a Gouy phase shift, and the transverse structure of this phase shift is characterized by the Gouy radius. A new expression is obtained for this radius in terms of the parameters
Silicon single-photon avalanche diodes for high-performance parallel photon timing
NASA Astrophysics Data System (ADS)
Gulinatti, Angelo; Rech, Ivan; Cammi, Corrado; Labanca, Ivan; Maccagnani, Piera; Ghioni, Massimo
2012-06-01
Thanks to the steady improvement in the detectors' performance, single-photon techniques are nowadays employed in a large number of applications ranging from single molecule dynamics to astronomy. In particular, silicon Single Photon Avalanche Diodes (SPAD) play a crucial role in this field thanks to their remarkable performance in terms of Photon Detection Efficiency (PDE), temporal response and Dark Count Rate (DCR). While CMOS technology allows the fabrication of large arrays of SPAD with built-in electronics, it is only resorting to custom fabrication processes that is possible to attain detectors with high-end performance required by most demanding applications. However, the fabrication of arrays for timing applications, even with a small number of pixels, is quite challenging with custom processes owing to electrical coupling between pixels. In this paper we will discuss technological solutions for the fabrication of arrays of high-performance SPAD for parallel photon timing.