Photon Number Statistics of Multimode Parametric Down-Conversion
M. Avenhaus; H. B. Coldenstrodt-Ronge; K. Laiho; W. Mauerer; I. A. Walmsley; C. Silberhorn
2008-08-07
We experimentally analyze the complete photon number statistics of parametric downconversion and ascertain the influence of multimode effects. Our results clearly reveal a difference between single mode theoretical description and the measured distributions. Further investigations assure the applicability of loss-tolerant photon number reconstruction and prove strict photon number correlation between signal and idler modes.
Fujiwara, Mikio; Sasaki, Masahide
2007-06-01
In optical quantum information technology, a photon number resolving detector (PNRD) is the basic device for developing photonic quantum computers. The demands for the PNRD are high quantum efficiency and wide dynamic range. We have developed a charge integration photon detector (CIPD) with a quantum efficiency of 80% at telecom wavelengths. The repetition rate of the CIPD is as low as 40 Hz at present, but it can be applied for measurement of short pulses. We report the capability of the CIPD for multiphoton counting over 10 photons, its responsivity to the short pulses, and its high linearity using a binary intensity modulated short pulse (2 ns) train and simultaneous irradiation of two kinds of pulses. PMID:17514257
Direct detection of super-thermal photon-number statistics in second-harmonic generation.
Allevi, Alessia; Bondani, Maria
2015-07-01
Changes in the statistical properties of light undergoing second-harmonic generation are investigated in the photon-number-resolving domain. We theoretically demonstrate that when a portion of multimode thermal light produced by parametric down-conversion is up-converted, both the second-harmonics and the residual beam at the fundamental wavelength are endowed with super-thermal photon-number distributions. The experimental results, which were obtained by exploiting the photo-number-resolving capability of hybrid photodetectors, are in excellent agreement with the theoretical expectations. PMID:26125374
How colors influence numbers: Photon statistics of parametric down-conversion
Wolfgang Mauerer; Malte Avenhaus; Wolfram Helwig; Christine Silberhorn
2009-01-01
Parametric down-conversion (PDC) is a technique of ubiquitous experimental significance in the production of nonclassical, photon-number-correlated twin beams. Standard theory of PDC as a two-mode squeezing process predicts and homodyne measurements observe a thermal photon number distribution per beam. Recent experiments have obtained conflicting distributions. In this article, we explain the observation by an a priori theoretical model solely based
How colors influence numbers: Photon statistics of parametric down-conversion
NASA Astrophysics Data System (ADS)
Mauerer, Wolfgang; Avenhaus, Malte; Helwig, Wolfram; Silberhorn, Christine
2009-11-01
Parametric down-conversion (PDC) is a technique of ubiquitous experimental significance in the production of nonclassical, photon-number-correlated twin beams. Standard theory of PDC as a two-mode squeezing process predicts and homodyne measurements observe a thermal photon number distribution per beam. Recent experiments have obtained conflicting distributions. In this article, we explain the observation by an a priori theoretical model solely based on directly accessible physical quantities. We compare our predictions with experimental data and find excellent agreement.
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 V. Ilyin
2015-05-28
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.
On the photon statistics of light scattered by a small number of particles
J. K?epelka; J. Pe?ina; P. Št?pánek; ?. Ko?ák
1984-01-01
We compare experimental and theoretical data for the photocount distribution of light scattered by a small number of particles using the log-normal intensity probability distribution and that followed from a random walk formulation. We present a table and nomograms making it possible to determine simply small numbers of scattering particles from the photocount distribution of scattered light. For the mean
V. N. Starkov; A. A. Semenov; H. V. Gomonay
2009-07-18
We demonstrate a practical possibility of loss compensation in measured photocounting statistics in the presence of dark counts and background radiation noise. It is shown that satisfactory results are obtained even in the case of low detection efficiency and large experimental errors.
Starkov, V. N.; Semenov, A. A.; Gomonay, H. V.
2009-07-15
We demonstrate a practical possibility of loss compensation in measured photocounting statistics in the presence of dark counts and background radiation noise. It is shown that satisfactory results are obtained even in the case of low detection efficiency and large experimental errors.
Photon statistics of intense entangled photon pulses
NASA Astrophysics Data System (ADS)
Schlawin, Frank; Mukamel, Shaul
2013-09-01
Time- and frequency-gated two-photon counting is given by a four-time correlation function of the electric field. This reduces to two times with purely time gating. We calculate this function for entangled photon pulses generated by parametric down-conversion. At low intensity, the pulses consist of well-separated photon pairs, and crossover to squeezed light as the intensity is increased. This is illustrated by the two-photon absorption signal of a three-level model, which scales linearly for a weak pump intensity where both photons come from the same pair, and gradually becomes nonlinear as the intensity is increased. We find that the strong frequency correlations of entangled photon pairs persist even for higher photon numbers. This could help facilitate the application of these pulses to nonlinear spectroscopy, where these correlations can be used to manipulate congested signals.
Characterization of photon statistics in a single-photon source via variable attenuation
Zhang Shengli; Zou Xubo; Li Chuanfeng; Guo Guangcan; Jin Chenhui
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.
Photon Statistics of a Non-Stationary Periodically Driven Single-Photon Source
M. Hennrich; T. Legero; A. Kuhn; G. Rempe
2004-06-05
We investigate the photon statistics of a single-photon source that operates under non-stationary conditions. The photons are emitted by shining a periodic sequence of laser pulses on single atoms falling randomly through a high-finesse optical cavity. Strong antibunching is found in the intensity correlation of the emitted light, demonstrating that a single atom emits photons one-by-one. However, the number of atoms interacting with the cavity follows a Poissonian statistics so that, on average, no sub-Poissonian photon statistics is obtained, unless the measurement is conditioned on the presence of single atoms.
Photon Counts Statistics in Leukocyte Cell Dynamics
NASA Astrophysics Data System (ADS)
van Wijk, Eduard; van der Greef, Jan; van Wijk, Roeland
2011-12-01
In the present experiment ultra-weak photon emission/ chemiluminescence from isolated neutrophils was recorded. It is associated with the production of reactive oxygen species (ROS) in the "respiratory burst" process which can be activated by PMA (Phorbol 12-Myristate 13-Acetate). Commonly, the reaction is demonstrated utilizing the enhancer luminol. However, with the use of highly sensitive photomultiplier equipment it is also recorded without enhancer. In that case, it can be hypothesized that photon count statistics may assist in understanding the underlying metabolic activity and cooperation of these cells. To study this hypothesis leukocytes were stimulated with PMA and increased photon signals were recorded in the quasi stable period utilizing Fano factor analysis at different window sizes. The Fano factor is defined by the variance over the mean of the number of photon within the observation time. The analysis demonstrated that the Fano factor of true signal and not of the surrogate signals obtained by random shuffling increases when the window size increased. It is concluded that photon count statistics, in particular Fano factor analysis, provides information regarding leukocyte interactions. It opens the perspective to utilize this analytical procedure in (in vivo) inflammation research. However, this needs further validation.
Martin Hamar; Jan Perina Jr.; Ondrej Haderka
2005-01-01
Measurement of photon-number statistics of fields composed of photon pairs generated in spontaneous parametric down-conversion pumped by strong ultrashort pulses is described. Finite detection quantum efficiencies, noises as well as possible loss of one or both photons from a pair are taken into account. Measured data provided by an intensified CCD camera are analyzed along the developed model. The joint
Photon statistics and polarization correlations at telecommunications
Orozco, Luis A.
Photon statistics and polarization correlations at telecommunications wavelengths from a warm of heralded single photons at a telecommunication wavelength. We measure the heralded autocorrelation and see. Kuzmich, "Quantum telecommunication based on atomic cascade transitions," Phys. Rev. Lett. 96, 093604
Quantum Random Number Generator using Photon-Number Path Entanglement
Osung Kwon; Young-Wook Cho; Yoon-Ho Kim
2008-08-04
We report a novel quantum random number generator based on the photon-number$-$path entangled state which is prepared via two-photon quantum interference at a beam splitter. The randomness in our scheme is of truly quantum mechanical origin as it comes from the projection measurement of the entangled two-photon state. The generated bit sequences satisfy the standard randomness test.
Observation of sub-Poissonian photon statistics in a micromaser
Rempe, G.; Schmidt-Kaler, F.; Walther, H. Max-Planck-Institut fuer Quantenoptik, D-8046 Garching bei Muenchen )
1990-06-04
We describe the first investigation of the nonclassical radiation field of a micromaser. The maser cavity is cooled to 0.5 K to exclude thermal photons and has a quality factor 3{times}10{sup 10}. Velocity-selected Rydberg atoms pump the maser. The photon statistics in the cavity are measured via the statistics of the atoms leaving the cavity in the lower maser level. Taking into account a detection efficiency of 10%, their fluctuations are reduced up to 40% below the Poisson level. This corresponds to photon-number fluctuations in the cavity of up to 70% below the vacuum-state limit.
Quantum statistics of photon cloning machines
NASA Astrophysics Data System (ADS)
D'Ariano, G. M.; De Martini, F.; Macchiavello, C.
2001-05-01
We show an experiment to study the statistics of the output state of an optimal N? M cloning machine that produces indistinguishable clones. The experiment is based on a photonic implementation of universal cloning transformations.
Photon-number correlations by photon-number resolving detectors
Alessia Allevi; Maria Bondani; Alessandra Andreoni
2010-02-01
We demonstrate that by using a pair of photodetectors endowed with internal gain we are able to quantify the correlation coefficient between the two components of a pulsed bipartite state in the mesoscopic intensity regime (less than 100 mean photons).
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.
Odd numbers of photons and teleportation
Enk, S.J. van
2003-02-01
Several teleportation protocols, namely those using entangled coherent states, entangled squeezed states, and the single-photon Einstein-Podolsky-Rosen state, are all shown to be particular instances of a more general scheme that relies on the detection of an odd number of photons.
Efficient and robust quantum random number generation by photon number detection
NASA Astrophysics Data System (ADS)
Applegate, M. J.; Thomas, O.; Dynes, J. F.; Yuan, Z. L.; Ritchie, D. A.; Shields, A. J.
2015-08-01
We present an efficient and robust quantum random number generator based upon high-rate room temperature photon number detection. We employ an electric field-modulated silicon avalanche photodiode, a type of device particularly suited to high-rate photon number detection with excellent photon number resolution to detect, without an applied dead-time, up to 4 photons from the optical pulses emitted by a laser. By both measuring and modeling the response of the detector to the incident photons, we are able to determine the illumination conditions that achieve an optimal bit rate that we show is robust against variation in the photon flux. We extract random bits from the detected photon numbers with an efficiency of 99% corresponding to 1.97 bits per detected photon number yielding a bit rate of 143 Mbit/s, and verify that the extracted bits pass stringent statistical tests for randomness. Our scheme is highly scalable and has the potential of multi-Gbit/s bit rates.
Photon-number-resolving superconducting nanowire detectors
NASA Astrophysics Data System (ADS)
Mattioli, Francesco; Zhou, Zili; Gaggero, Alessandro; Gaudio, Rosalinda; Jahanmirinejad, Saeedeh; Sahin, Döndü; Marsili, Francesco; Leoni, Roberto; Fiore, Andrea
2015-10-01
In recent years, photon-number-resolving (PNR) detectors have attracted great interest, mainly because they can play a key role in diverse application fields. A PNR detector with a large dynamic range would represent an ideal photon detector, bringing the linear response of conventional analogue detectors down to the single-photon level. Several technologies, such as InGaAs single photon avalanche detectors (SPADs), arrays of silicon photomultipliers, InGaAs SPADs with self-differencing circuits and transition edge sensors have shown photon number resolving capability. Superconducting nanowires provide free-running single-photon sensitivity from visible to mid-infrared frequencies, low dark counts, excellent timing resolution (<60 ps) and short dead time (?10 ns), at an easily accessible temperature (2–3 K), but they do not inherently resolve the photon number. In this framework, PNR detectors based on arrays of superconducting nanowires have been proposed. In this article we describe a number of methods and device configurations that have been pursued to obtain PNR capability using superconducting nanowire detectors.
Statistical approaches for probing single-molecule dynamics photon-by-photon
Xie, Xiaoliang Sunney
Statistical approaches for probing single-molecule dynamics photon-by-photon Haw Yang1 , X. Sunney 02138, USA Received 19 December 2001 Abstract The recently developed photon-by-photon approach [H. Yang, each photon represents a data point, thereby affording better statistics. Here, we utilize
Statistics: It's in the Numbers!
ERIC Educational Resources Information Center
Deal, Mary M.; Deal, Walter F., III
2007-01-01
Mathematics and statistics play important roles in peoples' lives today. A day hardly passes that they are not bombarded with many different kinds of statistics. As consumers they see statistical information as they surf the web, watch television, listen to their satellite radios, or even read the nutrition facts panel on a cereal box in the…
Counting statistics of collective photon transmissions
Vogl, M. Schaller, G. 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.
Photon-Statistics Excitation Spectroscopy of a Quantum-Dot Micropillar Laser
NASA Astrophysics Data System (ADS)
Kazimierczuk, T.; Schmutzler, J.; Aßmann, M.; Schneider, C.; Kamp, M.; Höfling, S.; Bayer, M.
2015-07-01
We introduce photon-statistics excitation spectroscopy and exemplarily apply it to a quantum-dot micropillar laser. Both the intensity and the photon number statistics of the emission from the micropillar show a strong dependence on the photon statistics of the light used for excitation of the sample. The results under coherent and pseudothermal excitation reveal that a description of the laser properties in terms of mean input photon numbers is not sufficient. It is demonstrated that the micropillar acts as a superthermal light source when operated close to its threshold. Possible applications for important spectroscopic techniques are discussed.
Photon-Statistics Excitation Spectroscopy of a Quantum-Dot Micropillar Laser.
Kazimierczuk, T; Schmutzler, J; Assmann, M; Schneider, C; Kamp, M; Höfling, S; Bayer, M
2015-07-10
We introduce photon-statistics excitation spectroscopy and exemplarily apply it to a quantum-dot micropillar laser. Both the intensity and the photon number statistics of the emission from the micropillar show a strong dependence on the photon statistics of the light used for excitation of the sample. The results under coherent and pseudothermal excitation reveal that a description of the laser properties in terms of mean input photon numbers is not sufficient. It is demonstrated that the micropillar acts as a superthermal light source when operated close to its threshold. Possible applications for important spectroscopic techniques are discussed. PMID:26207501
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.
Department: Statistics Course number: STAT 202W
Alpay, S. Pamir
Department: Statistics Course number: STAT 202W Title: Undergraduate Seminar II Credits: 1 Contact, and choose one statistical topic to investigate in detail. The student will write a well revised will attend 6-8 seminars per semester, and choose one statistical topic to investigate in detail. The student
UNIQUE NUMBERS: 04610, 04620 STATISTICS AND MODELING
Ghosh, Joydeep
and understanding of statistical analysis and #12;allow you to build models appropriate to a business problemSTA 371G UNIQUE NUMBERS: 04610, 04620 STATISTICS AND MODELING SPRING 2014 Professor Stathis.Malladi@phd.mccombs.utexas.edu Course Web Page via Canvas Course Objectives This course introduces the techniques of Statistical
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.
Nonlinearity sensing via photon-statistics excitation spectroscopy
Assmann, Marc; Bayer, Manfred
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.
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.
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.
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.
Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.; Hage, B.; Lam, P. K.; Symul, T. [Centre for Quantum Computation and Communication Technology, Quantum Optics group, Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Lund, A. P. [Centre for Quantum Computation and Communication Technology, Centre for Quantum Dynamics, Griffith University, Nathan QLD 4111 (Australia); Ralph, T. C. [Centre for Quantum Computation and Communication Technology, Department of Physics, University of Queensland, St. Lucia QLD 4072 (Australia)
2011-11-15
The nonlinearity of a conditional photon-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for photon-number resolution using only homodyne detection. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-photon-subtracted squeezed vacuum states. Although our photon-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, photon-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.
Interferometry with a photon-number resolving detector
Wildfeuer, Christoph F; Chen, Jun; Fan, Jingyun; Migdall, Alan; Dowling, Jonathan P
2009-01-01
With photon-number resolving detectors, we show compression of interference fringes with increasing photon numbers for a Fabry-Perot interferometer. This feature provides a higher precision in determining the position of the interference maxima compared to a classical detection strategy. We also theoretically show supersensitivity if N-photon states are sent into the interferometer and a photon-number resolving measurement is performed.
Room temperature photon number resolving detector for infared wavelengths.
Pomarico, Enrico; Sanguinetti, Bruno; Thew, Rob; Zbinden, Hugo
2010-05-10
In this paper we present a photon number resolving detector at infrared wavelengths, operating at room temperature and with a large dynamic range. It is based on the up-conversion of a signal at 1559 nm into visible wavelength and on its detection by a thermoelectrically cooled multi-pixel silicon avalanche photodiodode, also known as a Silicon Photon Multiplier. With the appropriate up-conversion this scheme can be implemented for arbitrary wavelengths above the visible spectral window. The preservation of the poissonian statistics when detecting coherent states is studied and the cross-talk effects on the detected signal can be easily estimated in order to calibrate the detector. This system is well suited for measuring very low intensities at infrared wavelengths and for analyzing multiphoton quantum states. PMID:20588927
Room temperature photon number resolving detector at telecom wavelengths
Enrico Pomarico; Bruno Sanguinetti; Rob Thew; Hugo Zbinden
2010-03-29
Large dynamic range room temperature photon number resolving (PNR) detectors can be very useful for measuring very low light intensities and for analyzing multiphoton quantum states. In this paper we present a PNR detector based on the up-conversion (UC) of telecom signal into visible wavelength and on its detection by a thermoelectrically cooled multi-pixel silicon avalanche photodiodode (APD), also known as Silicon Photon Multiplier (SiPM). An efficiency of 4% is attained and the poissonian statistics of input coherent states is maintained up to approximately 20 simultaneous detections. The cross-talk effects on the detected signal are estimated in order to properly calibrate the detector. This scheme can be used at arbitrary wavelengths above the visible spectral window with appropriate up-conversion.
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.
Testing photons' Bose-Einstein statistics with Compton scattering
Altschul, Brett [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States)
2010-11-15
It is an empirical question whether photons always obey Bose-Einstein statistics, but devising and interpreting experimental tests of photon statistics can be a challenge. The nonrelativistic cross section for Compton scattering illustrates how a small admixture {nu} of wrong-sign statistics leads to a loss of gauge invariance; there is a large anomalous amplitude for scattering timelike photons. Nevertheless, one can interpret the observed transparency of the solar wind plasma at low frequencies as a bound {nu}<10{sup -25} if Lorentz symmetry is required. If there is instead a universal preferred frame, the bound is {nu}<10{sup -14}, still strong compared with previous results.
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.
Excitations of photon-number states in Kerr nonlinear resonator at finite temperatures
G. H. Hovsepyan; G. Yu. Kryuchkyan
2015-03-29
We investigate temperature reservoir effects in a lossy Kerr nonlinear resonator considering selective excitation of ooscillatory mode driven by a sequence of Gaussian pulses. In this way, we analyze time-dependent populations of photon-number states and quantum statistics on the base of second-order photon correlation function in one-photon and two-photon transitions. The effects coming from thermal reservoirs are interesting for performing more realistic approach to generate Fock states and for study phenomena connecting quantum engineering and temperature. We also study the role of pulse-shaping effects during selective excitation.
Exploration of photon-number entangled states using weak nonlinearities
Yingqiu He; Dong Ding; Fengli Yan; Ting Gao
2015-04-03
A method for exploring photon-number entangled states with weak nonlinearities is described. We show that it is possible to create and detect such entanglement at various scales, ranging from microscopic to macroscopic systems. In the present architecture, we suggest that the maximal phase shift induced in the process of interaction between photons is proportional to photon numbers. Also, in the absence of decoherence we analyze maximum error probability and show its feasibility with current technology.
NASA Astrophysics Data System (ADS)
Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei
2015-03-01
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.
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
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
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.
Towards a Metric to Estimate Atomic Number from Backscattered Photons
Walston, S; Dietrich, D; Wurtz, R
2009-08-17
An ability to determine the atomic number of a material in a cargo container would be helpful in interdicting smuggled nuclear materials. This paper examines two processes by which high energy photons interact with matter; Compton scattering and pair production. The ratio of the number of photons which originate from the annihilation of positrons resulting from pair production and the number of photons coming from Compton scattering gives a good indication of atomic number. At large angles relative to an incident beam - i.e. backscattered, there is good separation in energy between Compton scattered photons and photons from positron annihilations. This ratio can then be cleanly determined in order to estimate atomic number.
Photon-number resolution using time-multiplexed single-photon detectors
Fitch, M.J.; Jacobs, B.C.; Pittman, T.B.; Franson, J.D.
2003-10-01
Photon-number-resolving detectors are needed for a variety of applications including linear-optics quantum computing. Here we describe the use of time-multiplexing techniques that allow ordinary single-photon detectors, such as silicon avalanche photodiodes, to be used as photon-number-resolving detectors. The ability of such a detector to correctly measure the number of photons for an incident number state is analyzed. The predicted results for an incident coherent state are found to be in good agreement with the results of a proof-of-principle experimental demonstration.
Waveguide photon-number-resolving detectors for quantum photonic integrated circuits
D. Sahin; A. Gaggero; Z. Zhou; S. Jahanmirinejad; F. Mattioli; R. Leoni; J. Beetz; M. Lermer; M. Kamp; S. Höfling; A. Fiore
2013-08-21
Quantum photonic integration circuits are a promising approach to scalable quantum processing with photons. Waveguide single-photon-detectors (WSPDs) based on superconducting nanowires have been recently shown to be compatible with single-photon sources for a monolithic integration. While standard WSPDs offer single-photon sensitivity, more complex superconducting nanowire structures can be configured to have photon-number-resolving capability. In this work, we present waveguide photon-number-resolving detectors (WPNRDs) on GaAs/Al0.75Ga0.25As ridge waveguides based on a series connection of nanowires. The detection of 0-4 photons has been demonstrated with a four-wire WPNRD, having a single electrical read-out. A device quantum efficiency ~24 % is reported at 1310 nm for the TE polarization.
Extreme Value Statistics in Silicon Photonics
Jalali. Bahram
(CARS), in the presence of a noisy pump, follows similar power-law statistics. We describe a model functions, a set of power-law distributions in which events much larger than the mean (outliers) can occur of quantum fluctuations in the amplified spontaneous emission in fibers [6][11]. The effects of dispersion
Conditional preparation of states containing a definite number of photons
O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Boyd, Robert W.; Lakshminarayanan, Vasudevan
2008-02-15
A technique for conditionally creating single-mode or multimode photon-number states is analyzed using Bayesian theory. We consider the heralded N-photon states created from the photons produced by an unseeded optical parametric amplifier when the heralding detector is the time-multiplexed photon-number-resolving detector recently demonstrated by Fitch et al. [Phys. Rev. A 68, 043814 (2003)] and simultaneously by Achilles et al. [Opt. Lett. 28, 2387 (2003)]. We find that even with significant loss in the heralding detector, fields with sub-Poissonian photon-number distributions can be created. We also show that heralded multimode fields created using this technique are more robust against detector loss than are single-mode fields.
Conditional preparation of states containing a definite number of photons
NASA Astrophysics Data System (ADS)
O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Lakshminarayanan, Vasudevan; Boyd, Robert W.
2008-02-01
A technique for conditionally creating single-mode or multimode photon-number states is analyzed using Bayesian theory. We consider the heralded N -photon states created from the photons produced by an unseeded optical parametric amplifier when the heralding detector is the time-multiplexed photon-number-resolving detector recently demonstrated by Fitch [Phys. Rev. A 68, 043814 (2003)] and simultaneously by Achilles [Opt. Lett. 28, 2387 (2003)]. We find that even with significant loss in the heralding detector, fields with sub-Poissonian photon-number distributions can be created. We also show that heralded multimode fields created using this technique are more robust against detector loss than are single-mode fields.
Photon Statistics of Single Carbon Nanotubes at Room Temperature
NASA Astrophysics Data System (ADS)
Ma, Xuedan; Duque, Juan; Crochet, Jared; Mangum, Benjamin; Doorn, Stephen; Htoon, Han
2013-03-01
Different from zero-dimensional systems such as atoms, molecules, and quantum dots, semiconducting single-walled carbon nanotubes (SWNTs) are ideal one-dimensional systems that allow free diffusion of excitons along their length. Studies have also shown that multiple excitons exist within the diffusion length can annihilate via Auger process. Interplay of Auger process and exciton diffusion therefore could have interesting effects on photon emission statistics of SWNTs. Current existing studies on photon emission statistics were conducted at low temperature where excitons were localized to quantum-dot-like states. To this end we conduct room temperature 2nd order photon correlation spectroscopy studies on high quality SWNTs capable of emitting continuous photoluminescence along their length which could extend up to several micrometers. We observed the degree of photon-bunching lower than 0.5 at the lowest pumping powers. We will also present a correlation between the diffusion length and the degree of photon-bunching. Our study could have implications toward utilizing SWNTs as room temperature single photon sources.
On the Optimal Mean Photon Number for Quantum Cryptography
Pearson, D; Pearson, David; Elliott, Chip
2004-01-01
The optimal mean photon number (mu) for quantum cryptography is the average photon number per transmitted pulse that results in the highest delivery rate of distilled cryptographic key bits, given a specific system scenario and set of assumptions about Eve's capabilities. Although many experimental systems have employed a mean photon number (mu) of 0.1 in practice, several research teams have pointed out that this value is somewhat arbitrary. In fact, various optimal values for mu have been described in the literature. In this paper we offer a detailed analytic model for an experimental, fiber-based quantum cryptographic system, and an explicit set of reasonable assumptions about Eve's current technical capabilities. We explicitly model total system behavior ranging from physical effects to the results of quantum cryptographic protocols such as error correction and privacy amplification. We then derive the optimal photon number (mu) for this system in a range of scenarios. One interesting result is that a mu ...
Misused Statistics: Straight Talk for Twisted Numbers.
ERIC Educational Resources Information Center
Jaffe, A. J.; Spirer, Herbert F.
Numerous misuses of statistics are described and illustrated, and ways of recognizing and avoiding such misuse are discussed. The following five categories of statistical misuse are identified: a lack of knowledge of the subject matter, the quality of the basic data, the preparation of the study and the report, the statistical methodology, and a…
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
Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength
NASA Astrophysics Data System (ADS)
Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide
2014-04-01
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.
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
Tomography of photon-number resolving continuous-output detectors
Peter C. Humphreys; Benjamin J. Metcalf; Thomas Gerrits; Thomas Hiemstra; Adriana E. Lita; Joshua Nunn; Sae Woo Nam; Animesh Datta; W. Steven Kolthammer; Ian A. Walmsley
2015-02-26
We report a comprehensive approach to analysing continuous-output photon detectors. We employ principal component analysis to maximise the information extracted, followed by a novel noise-tolerant parameterised approach to the tomography of PNRDs. We further propose a measure for rigorously quantifying a detector's photon-number-resolving capability. Our approach applies to all detectors with continuous-output signals. We illustrate our methods by applying them to experimental data obtained from a transition-edge sensor (TES) detector.
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
He, Y -H; Zhang, W -J; Zhang, L; Wu, J -J; Chen, S -J; You, L -X; Wang, Z
2015-01-01
Counting rate is a key parameter of superconducting nanowire single photon detectors (SNSPD) and is determined by the current recovery time of an SNSPD after a detection event. We propose a new method to study the transient detection efficiency (DE) and pulse amplitude during the current recovery process by statistically analyzing the single photon response of an SNSPD under photon illumination with a high repetition rate. The transient DE results match well with the DEs deduced from the static current dependence of DE combined with the waveform of a single-photon detection event. This proves that the static measurement results can be used to analyze the transient current recovery process after a detection event. The results are relevant for understanding the current recovery process of SNSPDs after a detection event and for determining the counting rate of SNSPDs.
NASA Astrophysics Data System (ADS)
He, Yu-Hao; Chao-Lin, Lü; Zhang, Wei-Jun; Zhang, Lu; Wu, Jun-Jie; Chen, Si-Jing; You, Li-Xing; Wang, Zhen
2015-06-01
A new method to study the transient detection efficiency (DE) and pulse amplitude of superconducting nanowire single photon detectors (SNSPD) during the current recovery process is proposed — statistically analyzing the single photon response under photon illumination with a high repetition rate. The transient DE results match well with the DEs deduced from the static current dependence of DE combined with the waveform of a single-photon detection event. This proves that static measurement results can be used to analyze the transient current recovery process after a detection event. The results are relevant for understanding the current recovery process of SNSPDs after a detection event and for determining the counting rate of SNSPDs. Project supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB04010200), the National Basic Research Program of China (Grant No. 2011CBA00202), and the National Natural Science Foundation of China (Grant No. 61401441).
Direct measurement of the Wigner function by photon-number-resolving detection
Niranjan Sridhar; Reihaneh Shahrokhshahi; Aaron J. Miller; Brice Calkins; Thomas Gerrits; Adriana Lita; Sae Woo Nam; Olivier Pfister
2014-09-24
Photon-number-revolving (PNR) detection allows the direct measurement of the Wigner quasiprobability distribution of an optical mode without the need for numerically processing an inverse Radon transform [K. Banaszek and K. W\\'odkiewicz, Phys. Rev. Lett. 76, 4344 (1996)]. In this work, we reproduced the seminal experiment of Banaszek et al. [Phys. Rev. A 60, 674 (1999)] of quantum tomography of a pure coherent state, and of a statistical mixture thereof, and extended it to the more general case of photon fluxes with much more than one photon per detection time. This was made possible by the use of a superconducting transition-edge sensor to perform PNR detection from 0 to 5 photons at 1064 nm, at about 70% system efficiency and with no dead time. We detail signal acquisition and detection efficiency and discuss prospects for applying such quantum tomography to non-Gaussian states.
The Stark effect and different photon statistics in two-photon atomic dynamics
NASA Astrophysics Data System (ADS)
Cardimona, D. A.; Kovanis, V.; Sharma, M. P.
Our main thrust in this paper is to investigate the effect of the Stark shifts on the atomic inversion dynamics when a multilevel atom interacts with a two-mode quantized radiation field. We utilize Hamiltonians that describe a Raman-type process as well as equal- and unequal-frequency two-photon absorption, and include the power-dependent Stark effect terms. We find that the Stark effect can fundamentally alter the atomic dynamics, by introducing exact periodicity depending on the tuning of the two modes of the applied field. Periodic collapses and revivals occur when the pump field is tuned on resonance for Raman scattering, tuned one coupling constant below resonance for unequal-frequency two-photon absorption, or tuned one or three coupling constants below resonance for equal-frequency two-photon absorption. After finding this major result, we briefly describe the effects of changing the width and mean in the photon statistical distributions, and find that as the photon mean increases, the early dynamics persist for longer times, and as the photon width increases, the widths of the revivals broaden.
High-speed quantum-random number generation by continuous measurement of arrival time of photons
NASA Astrophysics Data System (ADS)
Yan, Qiurong; Zhao, Baosheng; Hua, Zhang; Liao, Qinghong; Yang, Hao
2015-07-01
We demonstrate a novel high speed and multi-bit optical quantum random number generator by continuously measuring arrival time of photons with a common starting point. To obtain the unbiased and post-processing free random bits, the measured photon arrival time is converted into the sum of integral multiple of a fixed period and a phase time. Theoretical and experimental results show that the phase time is an independent and uniform random variable. A random bit extraction method by encoding the phase time is proposed. An experimental setup has been built and the unbiased random bit generation rate could reach 128 Mb/s, with random bit generation efficiency of 8 bits per detected photon. The random numbers passed all tests in the statistical test suite.
High-speed quantum-random number generation by continuous measurement of arrival time of photons.
Yan, Qiurong; Zhao, Baosheng; Hua, Zhang; Liao, Qinghong; Yang, Hao
2015-07-01
We demonstrate a novel high speed and multi-bit optical quantum random number generator by continuously measuring arrival time of photons with a common starting point. To obtain the unbiased and post-processing free random bits, the measured photon arrival time is converted into the sum of integral multiple of a fixed period and a phase time. Theoretical and experimental results show that the phase time is an independent and uniform random variable. A random bit extraction method by encoding the phase time is proposed. An experimental setup has been built and the unbiased random bit generation rate could reach 128 Mb/s, with random bit generation efficiency of 8 bits per detected photon. The random numbers passed all tests in the statistical test suite. PMID:26233362
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.
Elementary Business Statistics Unique Numbers 04100, 04105
Ghosh, Joydeep
AND LOCATION 04100 MW 11:00 - 12:30 pm UTC 4.104 (MOD Lab on assigned dates) 04105 MW 12:30 - 2:00 pm UTC 4.104 (MOD Lab on assigned dates) TEXT The Practice of Business Statistics, Using Data for Decisions, Second web site. Syllabi, notes, assignments, and other resources will be available within this site. Site
Number Hunting: Statistics on the Net.
ERIC Educational Resources Information Center
Raeder, Aggi
1996-01-01
Discusses how to find statistical data on the Internet, particularly with awareness of lag times associated with posted data and of the large quantity of university sources. Lists World Wide Web sites under the headings of metasites, agriculture, banking, business, crime, economics, education, energy, government, health, international, local…
Decoy state quantum key distribution with a photon number resolved heralded single photon source
Horikiri, Tomoyuki; Kobayashi, Takayoshi [Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), Tokyo, Japan and Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033 (Japan)
2006-03-15
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.
On the Optimal Mean Photon Number for Quantum Cryptography
David Pearson; Chip Elliott
2004-05-17
The optimal mean photon number (mu) for quantum cryptography is the average photon number per transmitted pulse that results in the highest delivery rate of distilled cryptographic key bits, given a specific system scenario and set of assumptions about Eve's capabilities. Although many experimental systems have employed a mean photon number (mu) of 0.1 in practice, several research teams have pointed out that this value is somewhat arbitrary. In fact, various optimal values for mu have been described in the literature. In this paper we offer a detailed analytic model for an experimental, fiber-based quantum cryptographic system, and an explicit set of reasonable assumptions about Eve's current technical capabilities. We explicitly model total system behavior ranging from physical effects to the results of quantum cryptographic protocols such as error correction and privacy amplification. We then derive the optimal photon number (mu) for this system in a range of scenarios. One interesting result is that mu of approximately 1.1 is optimal for a wide range of realistic, fiber-based QKD systems; in fact, it provides nearly 10 times the distilled throughput of systems that employ a more conventional mu = 0.1, without any adverse affect on system security, as judged against a set of reasonable assumptions about Eve's current capabilities.
Time-resolved statistics of nonclassical light in Josephson photonics
NASA Astrophysics Data System (ADS)
Dambach, Simon; Kubala, Björn; Gramich, Vera; Ankerhold, Joachim
2015-08-01
The interplay of the tunneling transfer of charges and the emission and absorption of light can be investigated in a setup, where a voltage-biased Josephson junction is connected in series with a microwave cavity. We focus here on the emission processes of photons and analyze the underlying time-dependent statistics using the second-order correlation function g(2 )(? ) and the waiting-time distribution w (? ) . Both observables highlight the crossover from a coherent light source to a single-photon source. Due to the nonlinearity of the Josephson junction, tunneling Cooper pairs can create a great variety of nonclassical states of light even at weak driving. Analytical results for the weak driving as well as the classical regime are complemented by a numerical treatment for the full nonlinear case. We also address the question of possible relations between g(2 )(? ) and w (? ) as well as the specific information which is provided by each of them.
Influence of phonons on exciton-photon interaction and photon statistics of a quantum dot
M. Bagheri Harouni; R. Roknizadeh; M. H. Naderi
2011-12-26
In this paper, we investigate, phonon effects on the optical properties of a spherical quantum dot. For this purpose, we consider the interaction of a spherical quantum dot with classical and quantum fields while the exciton of quantum dot interacts with a solid state reservoir. We show that phonons strongly affect the Rabi oscillations and optical coherence on first picoseconds of dynamics. We consider the quantum statistics of emitted photons by quantum dot and we show that these photons are anti-bunched and obey the sub-Poissonian statistics. In addition, we examine the effects of detuning and interaction of quantum dot with the cavity mode on optical coherence of energy levels. The effects of detuning and interaction of quantum dot with cavity mode on optical coherence of energy levels are compared to the effects of its interaction with classical pulse.
Plaçais, Bernard
Hanbury BrownTwiss Correlations to Probe the Population Statistics of GHz Photons Emitted of GHz photons in quantum circuits, using Hanbury Brown and Twiss correlations. The super-Poissonian and Poissonian photon statistics of thermal and coherent sources, respectively, made of a resistor and a radio
NASA Astrophysics Data System (ADS)
Arosio, V.; Caccia, M.; Chmill, V.; Ebolese, A.; Locatelli, M.; Martemiyanov, A.; Mattone, C.; Santoro, R.; Tintori, C.
2015-08-01
Silicon Photomultipliers are a new class of light sensitive detectors with single photon sensitivity and unprecedented photon number resolving capability. These properties open up the possibility to verify the statistics of the emitted light analysing the data collected by the sensor. In this paper, a procedure based on a Multi-Gaussian Fit of the spectrum and a model accounting for detector related effects is proposed and qualified using a LED illuminating a Silicon Photomultiplier.
Experimental Observation of Large Chern numbers in Photonic Crystals
Skirlo, Scott A; Igarashi, Yuichi; Joannopoulos, John; Soljacic, Marin
2015-01-01
Despite great interest in the quantum anomalous Hall phase and its analogs, all experimental studies in electronic and bosonic systems have been limited to a Chern number of one. Here, we perform microwave transmission measurements in the bulk and at the edge of ferrimagnetic photonic crystals. Bandgaps with large Chern numbers of 2, 3 and 4 are clearly present in the experimental results which show excellent agreement with theory. These large Chern number bandgaps support multimode one-way edge waveguides and can be used for the construction of topological power splitters and combiners.
Single photon laser altimeter simulator and statistical signal processing
NASA Astrophysics Data System (ADS)
Vacek, Michael; Prochazka, Ivan
2013-05-01
Spaceborne altimeters are common instruments onboard the deep space rendezvous spacecrafts. They provide range and topographic measurements critical in spacecraft navigation. Simultaneously, the receiver part may be utilized for Earth-to-satellite link, one way time transfer, and precise optical radiometry. The main advantage of single photon counting approach is the ability of processing signals with very low signal-to-noise ratio eliminating the need of large telescopes and high power laser source. Extremely small, rugged and compact microchip lasers can be employed. The major limiting factor, on the other hand, is the acquisition time needed to gather sufficient volume of data in repetitive measurements in order to process and evaluate the data appropriately. Statistical signal processing is adopted to detect signals with average strength much lower than one photon per measurement. A comprehensive simulator design and range signal processing algorithm are presented to identify a mission specific altimeter configuration. Typical mission scenarios (celestial body surface landing and topographical mapping) are simulated and evaluated. The high interest and promising single photon altimeter applications are low-orbit (˜10 km) and low-radial velocity (several m/s) topographical mapping (asteroids, Phobos and Deimos) and landing altimetry (˜10 km) where range evaluation repetition rates of ˜100 Hz and 0.1 m precision may be achieved. Moon landing and asteroid Itokawa topographical mapping scenario simulations are discussed in more detail.
Dovrat, L; Bakstein, M; Istrati, D; Shaham, A; Eisenberg, H S
2012-01-30
Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results. PMID:22330466
Jan Perina Jr; Ondrej Haderka; Martin Hamar; Vaclav Michalek
2012-02-07
The measurement of photon-number statistics of fields composed of photon pairs, generated in spontaneous parametric down-conversion and detected by an intensified CCD camera is described. Final quantum detection efficiencies, electronic noises, finite numbers of detector pixels, transverse intensity spatial profiles of the detected beams as well as losses of single photons from a pair are taken into account in a developed general theory of photon-number detection. The measured data provided by an iCCD camera with single-photon detection sensitivity are analyzed along the developed theory. Joint signal-idler photon-number distributions are recovered using the reconstruction method based on the principle of maximum likelihood. The range of applicability of the method is discussed. The reconstructed joint signal-idler photon-number distribution is compared with that obtained by a method that uses superposition of signal and noise and minimizes photoelectron entropy. Statistics of the reconstructed fields are identified to be multi-mode Gaussian. Elements of the measured as well as the reconstructed joint signal-idler photon-number distributions violate classical inequalities. Sub-shot-noise correlations in the difference of the signal and idler photon numbers as well as partial suppression of odd elements in the distribution of the sum of signal and idler photon numbers are observed.
How random are random numbers generated using photons?
Aldo Solis; Alí M. Angulo Martinez; Roberto Ramírez Alarcón; Hector Cruz Ramírez; Alfred B. U'Ren; Jorge G. Hirsch
2015-02-20
Randomness is fundamental in quantum theory, with many philosophical and practical implications. In this paper we discuss the concept of algorithmic randomness, which provides a quantitative method to assess the Borel normality of a given sequence of numbers, a necessary condition for it to be considered random. We use Borel normality as a tool to investigate the randomness of ten sequences of bits generated from the differences between detection times of photon pairs generated by spontaneous parametric downconversion. These sequences are shown to fulfil the randomness criteria without difficulties. As deviations from Borel normality for photon-generated random number sequences have been reported in previous work, a strategy to understand these diverging findings is outlined.
How random are random numbers generated using photons?
NASA Astrophysics Data System (ADS)
Solis, Aldo; Angulo Martínez, Alí M.; Ramírez Alarcón, Roberto; Cruz Ramírez, Hector; U’Ren, Alfred B.; Hirsch, Jorge G.
2015-06-01
Randomness is fundamental in quantum theory, with many philosophical and practical implications. In this paper we discuss the concept of algorithmic randomness, which provides a quantitative method to assess the Borel normality of a given sequence of numbers, a necessary condition for it to be considered random. We use Borel normality as a tool to investigate the randomness of ten sequences of bits generated from the differences between detection times of photon pairs generated by spontaneous parametric downconversion. These sequences are shown to fulfil the randomness criteria without difficulties. As deviations from Borel normality for photon-generated random number sequences have been reported in previous work, a strategy to understand these diverging findings is outlined.
Statistical measures applied to metal clusters: evidence of magic numbers
Sanudo, Jaime
2010-01-01
In this work, a shell model for metal clusters up to 220 valence electrons is used to obtain the fractional occupation probabilities of the electronic orbitals. Then, the calculation of a statistical measure of complexity and the Fisher-Shannon information is carried out. An increase of both magnitudes with the number of valence electrons is observed. The shell structure is reflected by the behavior of the statistical complexity. The magic numbers are indicated by the Fisher-Shannon information. So, as in the case of atomic nuclei, the study of statistical indicators also unveil the existence of magic numbers in metal clusters.
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.
Comment on the photon number bound and Rayleigh scattering
Jeremy Faupin; Israel Michael Sigal
2012-07-26
We discuss photon number bounds for a system of non-relativistic particles coupled to the quantized electromagnetic field (non-relativistic QED), below the ionization threshold. Such a bound was assumed in the proof of asymptotic completeness for Rayleigh scattering in our paper [3] (Condition (1.20) of Theorem 1.3 in [3]). We show how this assumption can be weakened and verified for a class of hamiltonians.
Photon number amplification/duplication through parametric conversion
NASA Technical Reports Server (NTRS)
Dariano, G. M.; Macchiavello, C.; Paris, M.
1993-01-01
The performance of parametric conversion in achieving number amplification and duplication is analyzed. It is shown that the effective maximum gains G(sub *) remain well below their integer ideal values, even for large signals. Correspondingly, one has output Fano factors F(sub *) which are increasing functions of the input photon number. On the other hand, in the inverse (deamplifier/recombiner) operating mode quasi-ideal gains G(sub *) and small factors F(sub *) approximately equal to 10 percent are obtained. Output noise and non-ideal gains are ascribed to spontaneous parametric emission.
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.
Time-resolved statistics of nonclassical light in Josephson photonics
Simon Dambach; Björn Kubala; Vera Gramich; Joachim Ankerhold
2015-08-18
The interplay of the tunneling transfer of charges and the emission and absorption of light can be investigated in a setup, where a voltage-biased Josephson junction is connected in series with a microwave cavity. We focus here on the emission processes of photons and analyze the underlying time-dependent statistics using the second-order correlation function $g^{(2)}(\\tau)$ and the waiting-time distribution $w(\\tau)$. Both observables highlight the crossover from a coherent light source to a single-photon source. Due to the nonlinearity of the Josephson junction, tunneling Cooper pairs can create a great variety of non-classical states of light even at weak driving. Analytical results for the weak driving as well as the classical regime are complemented by a numerical treatment for the full nonlinear case. We also address the question of possible relations between $g^{(2)}(\\tau)$ and $w(\\tau)$ as well as the specific information which is provided by each of them.
Observation of squeezed states with strong photon-number oscillations
Mehmet, Moritz; Vahlbruch, Henning; Lastzka, Nico; Danzmann, Karsten; Schnabel, Roman
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.
Enhancement of Photon Number Reflected by the Relativistic Flying Mirror
Kando, M.; Pirozhkov, A. S.; Kawase, K.; Esirkepov, T. Zh.; Fukuda, Y.; Kiriyama, H.; Okada, H.; Daito, I.; Kameshima, T.; Hayashi, Y.; Kotaki, H.; Mori, M.; Koga, J. K.; Daido, H.; Faenov, A. Ya.; Pikuz, T.; Ma, J.; Chen, L.-M.; Kawachi, T.; Kato, Y.
2009-12-04
Laser light reflection by a relativistically moving electron density modulation (flying mirror) in a wake wave generated in a plasma by a high intensity laser pulse is investigated experimentally. A counterpropagating laser pulse is reflected and upshifted in frequency with a multiplication factor of 37-66, corresponding to the extreme ultraviolet wavelength. The demonstrated flying mirror reflectivity (from 3x10{sup -6} to 2x10{sup -5}, and from 1.3x10{sup -4} to 0.6x10{sup -3}, for the photon number and pulse energy, respectively) is close to the theoretical estimate for the parameters of the experiment.
NASA Astrophysics Data System (ADS)
Faby, Sebastian; Maier, Joscha; Simons, David; Schlemmer, Heinz-Peter; Lell, Michael; Kachelrieß, Marc
2015-03-01
We present a novel increment matrix concept to simulate the correlations in an energy-selective photon counting detector. Correlations between the energy bins of neighboring detector pixels are introduced by scattered and fluorescence photons, together with the broadening of the induced charge clouds as they travel towards the electrodes, leading to charge sharing. It is important to generate statistically correct detector signals for the different energy bins to be able to realistically assess the detector's performance in various tasks, e.g. material decomposition. Our increment matrix concept describes the counter increases in neighboring pixels on a single event level. Advantages of our model are the fact that much less random numbers are required than simulating single photons and that the increment matrices together with their probabilities have to be generated only once and can be stored for later use. The different occurring increment matrix sets and the corresponding probabilities are simulated using an analytic model of the photon-matter-interactions based on the photoelectric effect and Compton scattering, and the charge cloud drift, featuring thermal diffusion and Coulomb expansion of the charge cloud. The results obtained with this model are evaluated in terms of the spectral response for different detector geometries and the resulting energy bin sensitivity. Comparisons to published measured data and a parameterized detector model show both a good qualitative and quantitative agreement. We also studied the resulting covariance of reconstructed energy bin images.
Double galaxy redshifts and the statistics of small numbers
NASA Technical Reports Server (NTRS)
Newman, William I.; Haynes, Martha P.; Terzian, Yervant
1989-01-01
Tifft (1980, 1982) claimed that observations of double galaxies reveal a 72 km/s periodicity. Sharp showed that the 'periodicities' in the observations are completely consistent with the statistics of small numbers. Here it is shown that Tifft's statistical procedure would ascribe a periodicity to small sets of Gaussian random noise. Satisfying the null hypothesis that the observations are not samples drawn from a normal population would require the acquisition of at least an order of magnitude more data.
Cavity QED determination of atomic number statistics in optical lattices
Chen, W.; Meiser, D.; Meystre, P.
2007-02-15
We study the reflection of two counterpropagating modes of the light field in a ring resonator by ultracold atoms either in the Mott insulator state or in the superfluid state of an optical lattice. We obtain exact numerical results for a simple two-well model and carry out statistical calculations appropriate for the full lattice case. We find that the dynamics of the reflected light strongly depends on both the lattice spacing and the state of the matter-wave field. Depending on the lattice spacing, the light field is sensitive to various density-density correlation functions of the atoms. The light field and the atoms become strongly entangled if the latter are in a superfluid state, in which case the photon statistics typically exhibits complicated multimodal structures.
Single-photon Resolved Cross-Kerr Interaction for Autonomous Stabilization of Photon-number States
E. T. Holland; B. Vlastakis; R. W. Heeres; M. J. Reagor; U. Vool; Z. Leghtas; L. Frunzio; G. Kirchmair; M. H. Devoret; M. Mirrahimi; R. J. Schoelkopf
2015-04-13
Quantum states can be stabilized in the presence of intrinsic and environmental losses by either applying active feedback conditioned on an ancillary system or through reservoir engineering. Reservoir engineering maintains a desired quantum state through a combination of drives and designed entropy evacuation. We propose and implement a quantum reservoir engineering protocol that stabilizes Fock states in a microwave cavity. This protocol is realized with a circuit quantum electrodynamics platform where a Josephson junction provides direct, nonlinear coupling between two superconducting waveguide cavities. The nonlinear coupling results in a single photon resolved cross-Kerr effect between the two cavities enabling a photon number dependent coupling to a lossy environment. The quantum state of the microwave cavity is discussed in terms of a net polarization and is analyzed by a measurement of its steady state Wigner function.
Generation of optical `Schrödinger cats' from photon number states
NASA Astrophysics Data System (ADS)
Ourjoumtsev, Alexei; Jeong, Hyunseok; Tualle-Brouri, Rosa; Grangier, Philippe
2007-08-01
Schrödinger's cat is a Gedankenexperiment in quantum physics, in which an atomic decay triggers the death of the cat. Because quantum physics allow atoms to remain in superpositions of states, the classical cat would then be simultaneously dead and alive. By analogy, a `cat' state of freely propagating light can be defined as a quantum superposition of well separated quasi-classical states-it is a classical light wave that simultaneously possesses two opposite phases. Such states play an important role in fundamental tests of quantum theory and in many quantum information processing tasks, including quantum computation, quantum teleportation and precision measurements. Recently, optical Schrödinger `kittens' were prepared; however, they are too small for most of the aforementioned applications and increasing their size is experimentally challenging. Here we demonstrate, theoretically and experimentally, a protocol that allows the generation of arbitrarily large squeezed Schrödinger cat states, using homodyne detection and photon number states as resources. We implemented this protocol with light pulses containing two photons, producing a squeezed Schrödinger cat state with a negative Wigner function. This state clearly exhibits several quantum phase-space interference fringes between the `dead' and `alive' components, and is large enough to become useful for quantum information processing and experimental tests of quantum theory.
Generation of optical 'Schrödinger cats' from photon number states.
Ourjoumtsev, Alexei; Jeong, Hyunseok; Tualle-Brouri, Rosa; Grangier, Philippe
2007-08-16
Schrödinger's cat is a Gedankenexperiment in quantum physics, in which an atomic decay triggers the death of the cat. Because quantum physics allow atoms to remain in superpositions of states, the classical cat would then be simultaneously dead and alive. By analogy, a 'cat' state of freely propagating light can be defined as a quantum superposition of well separated quasi-classical states-it is a classical light wave that simultaneously possesses two opposite phases. Such states play an important role in fundamental tests of quantum theory and in many quantum information processing tasks, including quantum computation, quantum teleportation and precision measurements. Recently, optical Schrödinger 'kittens' were prepared; however, they are too small for most of the aforementioned applications and increasing their size is experimentally challenging. Here we demonstrate, theoretically and experimentally, a protocol that allows the generation of arbitrarily large squeezed Schrödinger cat states, using homodyne detection and photon number states as resources. We implemented this protocol with light pulses containing two photons, producing a squeezed Schrödinger cat state with a negative Wigner function. This state clearly exhibits several quantum phase-space interference fringes between the 'dead' and 'alive' components, and is large enough to become useful for quantum information processing and experimental tests of quantum theory. PMID:17700695
Two dimensional photonic quasicrystal edge states protected by second Chern number
Zhang, Xiao
2015-01-01
Topological physics in photonic systems have attracted great attentions in recent years. In this work, we theoretically study the one and two dimensional photonic quasicrystal resonator lattices characterized by the first and second Chern number, which show exotic boundary states within the photonic energy band gap. In particular, the second Chern number protected edge states has opened up new possibilities for realizing topological physics of dimensions higher than three in photonic systems, which is highly sought for. Such photonic systems can be easily experimentally realized in regular photonic crystal with dielectric rods in air, by varying the radius of the rods, so we propose experiments realizing our predictions.
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
Photon-number-resolving decoy-state quantum key distribution
Cai Qingyu [State Key Laboratory of Magnetic Resonances and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Tan Yonggang [State Key Laboratory of Magnetic Resonances and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Graduation University of Chinese Academy of Sciences, Beijing 100081 (China)
2006-03-15
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 coherent sources. We show that Eve's coherent multiphoton pulse (CMP) attack is more efficient than a symmetric individual attack when the quantum bit error rate is small, so that the CMP attack should be considered to ensure the security of the final key. Our results show that a not-so-weak pulse can be used to transmit the key. Optimal intensity of the laser source is presented which provides a 23.9 km increase in the transmission distance.
The effect of center-of-mass motion on photon statistics
Yang Zhang; Jun Zhang; Shao-xiong Wu; Chang-shui Yu
2015-09-20
We analyze the photon statistics of a weakly driven cavity quantum electrodynamics system and discuss the effects of photon blockade and photon-induced tunneling by effectively utilizing instead of avoiding the center-of-mass motion of a two-level atom trapped in the cavity. With the resonant interaction between atom, photon and phonon, it is shown that the bunching and anti-bunching of photons can occur with properly driving frequency. Our study shows the influence of the imperfect cooling of atom on the blockade and provides an attempt to take advantage of the center-of-mass motion.
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.
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.
Photon number resolving detection at telecom wavelength with a charge integration photon detector
Mikio Fujiwara; Masahide Sasaki
2005-12-09
We demonstrate multiphoton discrimination at telecom wavelength with the readout frequency of 40 Hz by charge integration photon detector (CIPD). The CIPD consists of an InGaAs pin photodiode and a GaAs junction field effect transistor as a pre-amplifier in a charge integration circuit, which is cooled to 4.2 K to reduce thermal noise. The quantum efficiency of the CIPD (detector itself) is 80% for 1530 nm light, and the readout noise is measured as 0.26 electrons at 40 Hz. We can construct Poisson distributions of photo-carriers with distinguished peaks at each photo-carrier number corresponding to the signal to noise ratio of about 3.
Unified single-photon and single-electron counting statistics: From cavity QED to electron transport
Lambert, Neill; Chen, Yueh-Nan; Nori, Franco
2010-12-15
A key ingredient of cavity QED is the coupling between the discrete energy levels of an atom and photons in a single-mode cavity. The addition of periodic ultrashort laser pulses allows one to use such a system as a source of single photons--a vital ingredient in quantum information and optical computing schemes. Here we analyze and time-adjust the photon-counting statistics of such a single-photon source and show that the photon statistics can be described by a simple transport-like nonequilibrium model. We then show that there is a one-to-one correspondence of this model to that of nonequilibrium transport of electrons through a double quantum dot nanostructure, unifying the fields of photon-counting statistics and electron-transport statistics. This correspondence empowers us to adapt several tools previously used for detecting quantum behavior in electron-transport systems (e.g., super-Poissonian shot noise and an extension of the Leggett-Garg inequality) to single-photon-source experiments.
Resolving photon number states in a superconducting circuit
D. I. Schuster; A. A. Houck; J. A. Schreier; A. Wallraff; J. M. Gambetta; A. Blais; L. Frunzio; B. Johnson; M. H. Devoret; S. M. Girvin; R. J. Schoelkopf
2006-01-01
Electromagnetic signals are always composed of photons, though in the circuit domain those sig- nals are carried as voltages and currents on wires, and the discreteness of the photon's energy is usually not evident. However, by coupling a superconducting qubit to signals on a microwave trans- mission line, it is possible to construct an integrated circuit where the presence or
Resolving photon number states in a superconducting circuit
D. I. Schuster; A. A. Houck; J. A. Schreier; A. Wallrafi; J. M. Gambetta; A. Blais; L. Frunzio; B. Johnson; M. H. Devoret; S. M. Girvin; R. J. Schoelkopf
Electromagnetic signals are always composed of photons, though in the circuit domain those sig- nals are carried as voltages and currents on wires, and the discreteness of the photon's energy is usually not evident. However, by coupling a superconducting qubit to signals on a microwave trans- mission line, it is possible to construct an integrated circuit where the presence or
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
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.
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.
High-efficiency quantum-nondemolition single-photon-number-resolving detector
Munro, W.J.; Nemoto, Kae; Beausoleil, R.G.; Spiller, T.P.
2005-03-01
We discuss an approach to the problem of creating a photon-number-resolving detector using the giant Kerr nonlinearities available in electromagnetically induced transparency. Our scheme can implement a photon-number quantum-nondemolition measurement with high efficiency ({approx}99%) using fewer than 1600 atoms embedded in a dielectric waveguide.
Podoshvedov, S. A.
2007-04-15
The nonlinear {chi}{sup (2)} Mach-Zehnder interferometer is proposed as a device for conditional generation of a modified coherent nonclassical state. We show that the generated macroscopic state exhibits nonclassical effects, such as squeezing, photon antibunching, and sub-Poissonian statistics. The modified coherent state generates a macroscopic entangled state. The scheme works without the photon number resolving detection but requires high-efficiency photodetectors. We explain the mechanism of generation of the modified coherent non-classical state.
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.
Quantum Statistical Testing of a Quantum Random Number Generator
Humble, Travis S [ORNL
2014-01-01
The unobservable elements in a quantum technology, e.g., the quantum state, complicate system verification against promised behavior. Using model-based system engineering, we present methods for verifying the opera- tion of a prototypical quantum random number generator. We begin with the algorithmic design of the QRNG followed by the synthesis of its physical design requirements. We next discuss how quantum statistical testing can be used to verify device behavior as well as detect device bias. We conclude by highlighting how system design and verification methods must influence effort to certify future quantum technologies.
Quantum statistical testing of a quantum random number generator
NASA Astrophysics Data System (ADS)
Humble, Travis S.
2014-10-01
The unobservable elements in a quantum technology, e.g., the quantum state, complicate system verification against promised behavior. Using model-based system engineering, we present methods for verifying the operation of a prototypical quantum random number generator. We begin with the algorithmic design of the QRNG followed by the synthesis of its physical design requirements. We next discuss how quantum statistical testing can be used to verify device behavior as well as detect device bias. We conclude by highlighting how system design and verification methods must influence effort to certify future quantum technologies.
Direct observation of nonclassical photon statistics in parametric down-conversion
Edo Waks; Eleni Diamanti; Barry C. Sanders; Stephen D Bartlett; Yoshihisa Yamamoto
2004-01-01
We employ a high quantum efficiency photon number counter to determine the\\u000aphoton number distribution of the output field from a parametric downconverter.\\u000aThe raw photocount data directly demonstrates that the source is nonclassical\\u000aby forty standard deviations, and correcting for the quantum efficiency yields\\u000aa direct observation of oscillations in the photon number distribution.
Effects of propagation in air on photon statistics
Milonni, Peter W.
2003-01-01
Calculations of photon counting distributions and fade probabilities are compared with measured data obtained using very weak laser pulses propagated over 10-km horizontal paths. Good agreement is obtained between theory and experiment using various simplifying assumptions and values of the refractive-index structure constant C{sup 2}{sub n} lying within an expected range.
Particle number counting statistics in ideal Bose gases.
Weiss, C; Wilkens, M
1997-11-10
We discuss the exact particle number counting statistics of degenerate ideal Bose gases in the microcanonical, canonical, and grand-canonical ensemble, respectively, for various trapping potentials. We then invoke the Maxwell's Demon ensemble [Navez et el., Phys. Rev. Lett. (1997)] and show that for large total number of particles the root-mean-square fluctuation of the condensate occupation scales n0 / [T=Tc] r N s with scaling exponents r = 3=2, s = 1=2 for the3D harmonic oscillator trapping potential, and r = 1,s= 2=3 for the 3D box. We derive an explicit expression for r and s in terms of spatial dimension D and spectral index sigma of the single-particle energy spectrum. Our predictions also apply to systems where Bose-Einstein condensation does not occur. We point out that the condensate fluctuations in the microcanonical and canonical ensemble respect the principle of thermodynamic equivalence. PMID:19373413
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.
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
Photon Statistics and Coherence in Light Emission from a Random Laser Lucia Florescu and Sajeev John
John, Sajeev
diffusion, and the number of photons within each cell fluctuates in time due to atomic emission and absorp photon diffusion. We demonstrate that, with stronger scattering, the pumping threshold for the transition a simple but novel approach, based on a generalized master equation formalism describing mul- tiple light
Random lasers, L\\'evy statistics and spin glasses: Synergy between photonics and complex systems
Gomes, Anderson S L; Moura, André L; Fewo, Serge I; Pincheira, Pablo I R; Jerez, Vladimir; Maia, Lauro J Q; de Araújo, Cid B
2015-01-01
Random lasers have been recently approached as a photonic platform for disordered complex systems, such as spin glasses. In this work, using a Nd$^{3+}$:YBO$_3$ random laser system operating in the nonresonant (diffusive) feedback regime, we measured the distinct statistics of intensity fluctuations and show the physical origin of the complex interplay between the L\\'evy regime and the replica-symmetry-breaking transition to the photonic spin-glass phase. A novel result is reported: the unsaturated spin-glass behavior for high excitation pulse energies, not observed for systems with coherent feedback. Our experimental findings are corroborated by the present theoretical analysis. The results herein presented universalize the recent observation consistent with replica symmetry breaking in random lasers with coherent feedback, and also advance on the characterization of the fluctuation statistics of the photonic spin-glass phase, supported by recent theoretical works on the nonlinear optics of complex photonic ...
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.
Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength
Kentaro Wakui; Yujiro Eto; Hugo Benichi; Tetsufumi Yanagida; Shuro Izumi; Kazuhiro Ema; Takayuki Numata; Daiji Fukuda; Masahiro Takeoka; Masahide Sasaki
2013-08-08
Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Though an ultrabroadband nonclassical state from standard spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and quantum characterization have been a challenging task. Here we demonstrate the quantitative characterization of a multimode structure in such an ultrabroadband (150 nm FWHM) squeezed state at telecom wavelength (1.5 \\mu m). The nonclassical photon distribution of our highly multimode state is directly observed using a superconducting transition-edge sensor. From the observed photon correlation functions, we show that several tens of different squeezers are coexisting in the same spatial mode. We anticipate our results and technique open up a new possibility to generate and characterize nonclassical light sources for a large-scale optical quantum network in the frequency domain.
Statistical method for resolving the photon-photoelectron-counting inversion problem
Wu Jinlong [LMAM and School of Mathematical Sciences, Peking University, Beijing 100871 (China); Li Tiejun, E-mail: tieli@pku.edu.c [LMAM and School of Mathematical Sciences, Peking University, Beijing 100871 (China); Peng, Xiang, E-mail: xiangpeng@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Guo Hong, E-mail: hongguo@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)
2011-02-01
A statistical inversion method is proposed for the photon-photoelectron-counting statistics in quantum key distribution experiment. With the statistical viewpoint, this problem is equivalent to the parameter estimation for an infinite binomial mixture model. The coarse-graining idea and Bayesian methods are applied to deal with this ill-posed problem, which is a good simple example to show the successful application of the statistical methods to the inverse problem. Numerical results show the applicability of the proposed strategy. The coarse-graining idea for the infinite mixture models should be general to be used in the future.
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
Experience and grammatical agreement: statistical learning shapes number agreement production.
Haskell, Todd R; Thornton, Robert; Macdonald, Maryellen C
2010-02-01
A robust result in research on the production of grammatical agreement is that speakers are more likely to produce an erroneous verb with phrases such as the key to the cabinets, with a singular noun followed by a plural one, than with phrases such as the keys to the cabinet, where a plural noun is followed by a singular. These asymmetries are thought to reflect core language production processes. Previous accounts have attributed error patterns to a syntactic number feature present on plurals but not singulars. An alternative approach is presented in which a process similar to structural priming contributes to the error asymmetry via speakers' past experiences with related agreement constructions. A corpus analysis and two agreement production studies test this account. The results suggest that agreement production is shaped by statistical learning from past language experience. Implications for accounts of agreement are discussed. PMID:19942213
Experience and grammatical agreement: Statistical learning shapes number agreement production
Haskell, Todd R.; Thornton, Robert; MacDonald, Maryellen C.
2009-01-01
A robust result in research on the production of grammatical agreement is that speakers are more likely to produce an erroneous verb with phrases such as the key to the cabinets, with a singular noun followed by a plural one, than with phrases such as the keys to the cabinet, where a plural noun is followed by a singular. These asymmetries are thought to reflect core language production processes. Previous accounts have attributed error patterns to a syntactic number feature present on plurals but not singulars. An alternative approach is presented in which a process similar to structural priming contributes to the error asymmetry via speakers' past experiences with related agreement constructions. A corpus analysis and two agreement production studies test this account. The results suggest that agreement production is shaped by statistical learning from past language experience. Implications for accounts of agreement are discussed. PMID:19942213
Photon-number resolving detector based on a series array of superconducting nanowires
Saeedeh Jahanmirinejad; Giulia Frucci; Francesco Mattioli; Dondu Sahin; Alessandro Gaggero; Roberto Leoni; Andrea Fiore
2012-03-25
We present the experimental demonstration of a superconducting photon number resolving detector. It is based on the series connection of N superconducting nanowires, each connected in parallel to an integrated resistor. The device provides a single voltage readout, proportional to the number of photons absorbed in distinct nanowires. Clearly separated output levels corresponding to the detection of n=1-4 photons are observed in a 4-element detector fabricated from an NbN film on GaAs substrate, with a single-photon system quantum efficiency of 2.6% at the wavelength of 1300nm. The series-nanowire structure is promising in view of its scalability to large photon numbers and high efficiencies.
Dovrat, L; Istrati, D; Shaham, A; Eisenberg, H S
2011-01-01
Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to directly observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results.
Submillimeter Number Counts From Statistical Analysis of BLAST Maps
Patanchon, Guillaume; Bock, James J; Chapin, Edward L; Devlin, Mark J; Dicker, Simon R; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Marsden, Gaelen; Mauskopf, Philip; Moncelsi, Lorenzo; Netterfield, Calvin B; Olmi, Luca; Pascale, Enzo; Rex, Marie; Scott, Douglas; Semisch, Christopher; Thomas, Nicholas; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V
2009-01-01
We describe the application of a statistical method to estimate submillimeter galaxy number counts from the confusion limited observations of 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 analyse BLAST observations of a roughly 10 sq. deg 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 microns, instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with ...
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
Inexpensive hardware and software for photon statistics and correlation spectroscopy
Gamari, Benjamin D; Buckman, Richard E; Milas, Peker; Denker, John S; Chen, Hui; Li, Hongmin; Goldner, Lori S
2013-01-01
Single-molecule sensitive microscopies and spectroscopies are transforming biophysics and materials science laboratories. Techniques such as fluorescence correlation spectroscopy (FCS) and single-molecule sensitive fluorescence resonance energy transfer (FRET) are now commonly available in research laboratories but are as yet infrequently available in teaching laboratories. We describe inexpensive electronics and open-source software that bridges this gap, making state-of-the-art measurement research capabilities accessible to undergraduates interested in biophysics. We include a pedagogical discussion of the intensity correlation function relevant to FCS and its calculation directly from photon arrival times. We demonstrate the system with a measurement of the hydrodynamic radius of a protein using FCS that is suitable for an undergraduate teaching laboratory. The FPGA-based electronics, which are easy to construct, are suitable for more advanced measurements as well, and several applications are demonstrate...
Derivation of linear attenuation coefficients from CT numbers for low-energy photons.
Watanabe, Y
1999-09-01
One can estimate photon attenuation properties from the CT number. In a standard method one assumes that the linear attenuation coefficient is proportional to electron density and ignores its nonlinear dependence on atomic number. When the photon energy is lower than about 50 keV, such as for brachytherapy applications, however, photoelectric absorption and Rayleigh scattering become important. Hence the atomic number must be explicitly considered in estimating the linear attenuation coefficient. In this study we propose a method to more accurately estimate the linear attenuation coefficient of low-energy photons from CT numbers. We formulate an equation that relates the CT number to the electron density and the effective atomic number. We use a CT calibration phantom to determine unknown coefficients in the equation. The equation with a given CT number is then solved for the effective atomic number, which in turn is used to calculate the linear attenuation coefficient for low-energy photons. We use the CT phantom to test the new method. The method significantly improves the standard method in estimating the attenuation coefficient at low photon energies (20 keV < or = E < or = 40 keV) for materials with high atomic numbers. PMID:10495115
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.
Statistics of scattered photons from a driven three-level emitter in 1D open space
Roy, Dibyendu; Bondyopadhaya, Nilanjan
2014-01-07
We derive the statistics of scattered photons from a ?- or ladder-type three-level emitter (3LE) embedded in a 1D open waveguide. The weak probe photons in the waveguide are coupled to one of the two allowed transitions of the 3LE, and the other transition is driven by a control beam. This system shows electromagnetically induced transparency (EIT) which is accompanied with the Autler-Townes splitting (ATS) at a strong driving by the control beam, and some of these effects have been observed recently. We show that the nature of second-order coherence of the transmitted probe photons near two-photon resonance changes from bunching to antibunching to constant as strength of the control beam is ramped up from zero to a higher value where the ATS appears.
Willis, R T; Becerra, F E; Orozco, L A; Rolston, S L
2011-07-18
We present measurements of the polarization correlation and photon statistics of photon pairs that emerge from a laser-pumped warm rubidium vapor cell. The photon pairs occur at 780 nm and 1367 nm and are polarization entangled. We measure the autocorrelation of each of the generated fields as well as the cross-correlation function, and observe a strong violation of the two-beam Cauchy-Schwartz inequality. We evaluate the performance of the system as source of heralded single photons at a telecommunication wavelength. We measure the heralded autocorrelation and see that coincidences are suppressed by a factor of ? 20 from a Poissonian source at a generation rate of 1500 s(-1), a heralding efficiency of 10%, and a narrow spectral width. PMID:21934825
The Numbers Game: The Top 10 Sources for Statistics.
ERIC Educational Resources Information Center
Berinstein, Paula
1998-01-01
Lists and describes the 10 best sources for answering statistical questions that are available for free or at a low cost on the World Wide Web. Statistics search tips, government publishers, almanacs, and newspapers are discussed. (LRW)
Fitria Miftasani; Pawe? Machnikowski
2015-02-19
We present a theoretical analysis of the intensity autocorrelation for the spontaneous emission from a planar ensemble of self-assembled quantum dots. Using the quantum jump approach, we numerically simulate the evolution of the system and construct photon-photon delay time statistics that approximates the second order correlation function of the field. The form of this correlation function in the case of collective emission from a highly homogeneous ensemble qualitatively differs form that characterizing an ensemble of independent emitters (inhomogeneous ensemble of uncoupled dots). The signatures of collective emission in the intensity correlations are observed also in the case of an inhomogeneous but sufficiently strongly coupled ensemble. Thus, we show that the second order correlation function of the emitted field provides a sensitive test of cooperative effects.
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…
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.
Li-Yun Hu; Zhi-Ming Zhang
2011-12-05
Using the thermal field dynamics theory to convert the thermal state to a "pure" state in doubled Fock space, it is found that the average value of e^{fa^{{\\dag}}a} under squeezed thermal state (STS) is just the generating function of Legendre polynomials, a remarkable result. Based on this point, the normalization and photon-number distributions of m-photon added (or subtracted) STS are conviently obtained as the Legendre polynomials. This new concise method can be expanded to the entangled case.
Submillimeter Number Counts from Statistical Analysis of BLAST Maps
NASA Astrophysics Data System (ADS)
Patanchon, Guillaume; Ade, Peter A. R.; Bock, James J.; Chapin, Edward L.; Devlin, Mark J.; Dicker, Simon R.; Griffin, Matthew; Gundersen, Joshua O.; Halpern, Mark; Hargrave, Peter C.; Hughes, David H.; Klein, Jeff; Marsden, Gaelen; Mauskopf, Philip; Moncelsi, Lorenzo; Netterfield, Calvin B.; Olmi, Luca; Pascale, Enzo; Rex, Marie; Scott, Douglas; Semisch, Christopher; Thomas, Nicholas; Truch, Matthew D. P.; Tucker, Carole; Tucker, Gregory S.; Viero, Marco P.; Wiebe, Donald V.
2009-12-01
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 deg2 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 ?m 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 ?m, and -4.5 at 350 and 500 ?m, over the range ~0.02-0.5 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.
SUBMILLIMETER NUMBER COUNTS FROM STATISTICAL ANALYSIS OF BLAST MAPS
Patanchon, Guillaume; Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Moncelsi, Lorenzo; Pascale, Enzo; Bock, James J.; Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas; Devlin, Mark J.; Dicker, Simon R.; Klein, Jeff; Rex, Marie; Gundersen, Joshua O.; Hughes, David H.; Netterfield, Calvin B.; Olmi, Luca
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.
Extreme value statistics and the Pareto distribution in silicon photonics
Borlaug, David; Jalali, Bahram
2008-01-01
L-shape probability distributions are extremely non-Gaussian distributions that have been surprisingly successful in describing the frequency of occurrence of extreme events, ranging from stock market crashes and natural disasters, the structure of biological systems, fractals, and optical rogue waves. In this paper, we show that fluctuations in stimulated Raman scattering in silicon, as well as in coherent anti-Stokes Raman scattering, can follow extreme value statistics and provide mathematical insight into the origin of this behavior. As an example of the experimental observations, we find that 16% of the Stokes pulses account for 84% of the pump energy transfer, an uncanny resemblance to the empirical Pareto principle or the 80/20 rule that describes important observation in socioeconomics.
NASA Astrophysics Data System (ADS)
Htoon, Han
2014-03-01
In the past decade, a tremendous amount of research efforts has been invested in the study of metal nanostructure (NM)-nanoemitter interactions. However, most of these studies have been conducted in the context of MNs interacting with single excitons. In contrast to these studies, we ventured into the realm of multi-exciton-MN interactions by performing low temperature photoluminescence (low-T PL) and photon-correlation spectroscopy studies on individual core/ultra-thick-shell NQDs (``giant''-NQDs or g-NQDs) deposited on nano-roughened silver films. Our low-T PL study show that (1) the multiexciton (MX) emissions in g-NQD coupled to silver films were enhanced mainly through the direct modification on the competition between the radiative and nonradiative recombination processes of MXs; and (2) strong enhancement in absorption is not necessary for a strong multiexciton emission. Our room temperature photon-correlation spectroscopy studies reveal that the MN-g-NQD interaction can transform sub-Poissonian photon emission statistics of individual g-NQDs to strong super-Poissonian statistics (photon-bunching). We further derived the conditions required for the manifestation of this phenomenon and show that it can also manifest in other nanoemitters such as epitaxially grown QDs and single walled carbon nanotubes. The understandings attained in this work could open a new plasmonic route for manipulation of important multiexciton processes such as optical amplification, lasing and entangled-photon-pair generation. J. Phys. Chem. Letts. 4, 1465-1470, (2013).
Zhang Yanbao; Knill, Emanuel; Glancy, Scott
2010-03-15
Because of the fundamental importance of Bell's theorem, a loophole-free demonstration of a violation of local realism (LR) is highly desirable. Here, we study violations of LR involving photon pairs. We quantify the experimental evidence against LR by using measures of statistical strength related to the Kullback-Leibler (KL) divergence, as suggested by van Dam et al.[W. van Dam, R. D. Gill, and P. D. Grunwald, IEEE Trans. Inf. Theory. 51, 2812 (2005)]. Specifically, we analyze a test of LR with entangled states created from two independent polarized photons passing through a polarizing beam splitter. We numerically study the detection efficiency required to achieve a specified statistical strength for the rejection of LR depending on whether photon counters or detectors are used. Based on our results, we find that a test of LR free of the detection loophole requires photon counters with efficiencies of at least 89.71%, or photon detectors with efficiencies of at least 91.11%. For comparison, we also perform this analysis with ideal unbalanced Bell states, which are known to allow rejection of LR with detector efficiencies above 2/3.
Muir, Ryan D.; Kissick, David J.; Simpson, Garth J.
2012-01-01
Data from photomultiplier tubes are typically analyzed using either counting or averaging techniques, which are most accurate in the dim and bright signal limits, respectively. A statistical means of adjoining these two techniques is presented by recovering the Poisson parameter from averaged data and relating it to the statistics of binomial counting from Kissick et al. [Anal. Chem. 82, 10129 (2010)]. The point at which binomial photon counting and averaging have equal signal to noise ratios is derived. Adjoining these two techniques generates signal to noise ratios at 87% to approaching 100% of theoretical maximum across the full dynamic range of the photomultiplier tube used. The technique is demonstrated in a second harmonic generation microscope. PMID:22535131
The Number of Guttman Errors as a Simple and Powerful Person-Fit Statistic.
ERIC Educational Resources Information Center
Meijer, Rob R.
1994-01-01
Through simulation, the power of the U3 statistic was compared with the power of one of the simplest person-fit statistics, the sum of the number of Guttman errors. In most cases, a weighted version of the latter statistic performed as well as the U3 statistic. (SLD)
Schmidt number for X-entanglement of photon pairs
NASA Astrophysics Data System (ADS)
Horoshko, D. B.; Patera, G.; Gatti, A.; Kolobov, M. I.
2012-06-01
We calculate the Schmidt number for a two-dimensional model of the nonfactorable spatiotemporal wave-function of biphotons produced in type-I spontaneous parametric down-conversion with degenerate and collinear phase- matching taking into consideration a major part of the broad spectral and angular bandwidth of the down- converted light. We derive an analytical expression for the Schmidt number as a function of the filter bandwidth in the limit of spectrally narrow pump.
Boosting up quantum key distribution by learning statistics of practical single photon sources
Yoritoshi Adachi; Takashi Yamamoto; Masato Koashi; Nobuyuki Imoto
2009-11-18
We propose a simple quantum-key-distribution (QKD) scheme for practical single photon sources (SPSs), which works even with a moderate suppression of the second-order correlation $g^{(2)}$ of the source. The scheme utilizes a passive preparation of a decoy state by monitoring a fraction of the signal via an additional beam splitter and a detector at the sender's side to monitor photon number splitting attacks. We show that the achievable distance increases with the precision with which the sub-Poissonian tendency is confirmed in higher photon number distribution of the source, rather than with actual suppression of the multi-photon emission events. We present an example of the secure key generation rate in the case of a poor SPS with $g^{(2)} = 0.19$, in which no secure key is produced with the conventional QKD scheme, and show that learning the photon-number distribution up to several numbers is sufficient for achieving almost the same achievable distance as that of an ideal SPS.
Disability and Employment. Disability Statistics Abstract Number 11.
ERIC Educational Resources Information Center
LaPlante, Mitchell P.; Kennedy, Jae; Kaye, H. Stephen; Wenger, Barbara L.
This statistical abstract summarizes recent data on the relationship between disability and employment. The statistics come from the Current Population Survey, the Census Bureau's Survey of Income and Program Participation, a poll of 1,000 Americans with disabilities, and administrative data on recipients of Social Security Disability Insurance…
Temporal Dynamics and Nonclassical Photon Statistics of Quadratically Coupled Optomechanical Systems
Shailendra Kumar Singh; S. V. Muniandy
2015-06-24
Quantum optomechanical system serves as an interface for coupling between photons and phonons due to mechanical oscillations. We used the Heisenberg-Langevin approach under Markovian white noise approximation to study a quadratically coupled optomechanical system which contains a thin dielectric membrane quadratically coupled to the cavity field. A decorrelation method is employed to solve for a larger number of coupled equations. Transient mean numbers of cavity photons and phonons that provide dynamical behaviour are computed for different coupling regime. We have also obtained the two-boson second-order correlation functions for the cavity field, membrane oscillator and their cross correlations that provide nonclassical properties governed by quadratic optomechanical system.
Temporal Dynamics and Nonclassical Photon Statistics of Quadratically Coupled Optomechanical Systems
NASA Astrophysics Data System (ADS)
Singh, Shailendra Kumar; Muniandy, S. V.
2015-05-01
Quantum optomechanical system serves as an interface for coupling between photons and phonons due to mechanical oscillations. We used the Heisenberg-Langevin approach under Markovian white noise approximation to study a quadratically coupled optomechanical system which contains a thin dielectric membrane quadratically coupled to the cavity field. A decorrelation method is employed to solve for a larger number of coupled equations. Transient mean numbers of cavity photons and phonons that provide dynamical behaviour are computed for different coupling regime. We have also obtained the two-boson second-order correlation functions for the cavity field, membrane oscillator and their cross correlations that provide nonclassical properties governed by quadratic optomechanical system.
Absolute calibration of photon-number-resolving detectors with an analog output using twin beams
NASA Astrophysics Data System (ADS)
Pe?ina, Jan; Haderka, Ond?ej; Allevi, Alessia; Bondani, Maria
2014-01-01
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.
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.
Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics
Samuel K. Lee; Mariangela Lisanti; Benjamin R. Safdi
2015-01-27
Data from the Fermi Large Area Telescope suggests that there is an extended excess of GeV gamma-ray photons in the Inner Galaxy. Identifying potential astrophysical sources that contribute to this excess is an important step in verifying whether the signal originates from annihilating dark matter. In this paper, we focus on the potential contribution of unresolved point sources, such as millisecond pulsars (MSPs). We propose that the statistics of the photons---in particular, the flux probability density function (PDF) of the photon counts below the point-source detection threshold---can potentially distinguish between the dark-matter and point-source interpretations. We calculate the flux PDF via the method of generating functions for these two models of the excess. Working in the framework of Bayesian model comparison, we then demonstrate that the flux PDF can potentially provide evidence for an unresolved MSP-like point-source population.
Statistical evaluation of photon count rate data for nanoscale particle measurement in wastewaters.
Smeraldi, Josh; Ganesh, Rajagopalan; Safarik, Jana; Rosso, Diego
2012-01-01
The dynamic light scattering (DLS) technique can detect the concentration and size distribution of nanoscale particles in aqueous solutions by analyzing photon interactions. This study evaluated the applicability of using photon count rate data from DLS analyses for measuring levels of biogenic and manufactured nanoscale particles in wastewater. Statistical evaluations were performed using secondary wastewater effluent and a Malvern Zetasizer. Dynamic light scattering analyses were performed equally by two analysts over a period of two days using five dilutions and twelve replicates for each dilution. Linearity evaluation using the sixty sample analysis yielded a regression coefficient R(2) = 0.959. The accuracy analysis for various dilutions indicated a recovery of 100 ± 6%. Precision analyses indicated low variance coefficients for the impact of analysts, days, and within sample error. The variation by analysts was apparent only in the most diluted sample (intermediate precision ~12%), where the photon count rate was close to the instrument detection limit. The variation for different days was apparent in the two most concentrated samples, which indicated that wastewater samples must be analyzed for nanoscale particle measurement within the same day of collection. Upon addition of 10 mg l(-1) of nanosilica to wastewater effluent samples, the measured photon count rates were within 5% of the estimated values. The results indicated that photon count rate data can effectively complement various techniques currently available to detect nanoscale particles in wastewaters. PMID:22048710
Generation of photon-number squeezed states with a fiber-optic symmetric interferometer.
Hosaka, Aruto; Hirosawa, Kenichi; Sawada, Ryota; Kannari, Fumihiko
2015-07-27
We numerically and experimentally demonstrate photon-number squeezed state generation with a symmetric fiber interferometer in an 800-nm wavelength and compared with an asymmetric fiber interferometer, although photon-number squeezed pulses have been generated only with asymmetric interferometers. Even though we obtain -1.0dB squeezing with an asymmetric fiber interferometer, since perfect spectral phase and intensity matching between displacement and signal pulses are achieved with a symmetric fiber interferometer, we obtain better squeezing of -3.1dB. We also numerically calculate and clarify this scheme's usefulness at a 1.55-?m wavelength. PMID:26367549
Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion
Gupta, Subhadeep; Moore, Kevin L.; Murch, Kater W.; Stamper-Kurn, Dan M.
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.
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…
The Statistics of the Number of Neutron Collisions Prior to Absorption
Pázsit, Imre
The Statistics of the Number of Neutron Collisions Prior to Absorption Sara A. Pozzi* Oak Ridge Accepted July 25, 2005 Abstract We propose a simple analytical model to describe the statistics, the energy transfer and the collision num- ber are related quantities, and therefore, the statistics of
Direct measurement of heralded single-photon statistics from a parametric down-conversion source
Hoeckel, David; Koch, Lars; Benson, Oliver [Nano Optics Group, Institute of Physics, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, 12489 Berlin (Germany)
2011-01-15
We present a full triple-coincidence analysis of photon-pair states generated by spontaneous parametric down-conversion. By increasing the coherence time of the source with the help of an intracavity setup, our measurements are not spoiled by detection time jitter. Signal-idler, but also thermal signal-signal, correlations are clearly resolved in this regime. Via introduction of an artificial coincidence window, we discuss in detail the transition to the previously studied cases where typically no single-arm correlation is observed. We investigate the heralded antibunching characteristics to show that in our system further studies of continuously generated photon states, possibly higher-photon-number entangled states, can be performed with respect to their (non)applicability in quantum information tasks.
Optimal sub-Poissonian light generation from twin beams by photon-number resolving detectors
Marco Lamperti; Alessia Allevi; Maria Bondani; Radek Machulka; Vaclav Michalek; Ondrej Haderka; Jan Perina Jr
2013-09-30
We generate nonclassical conditional states by exploiting the quantum correlations of multi-mode twin-beam states endowed with a sizeable number of photons. A strong relation between the sub-shot-noise correlations exhibited by twin beams and the sub-Poissonian character of the conditional states is experimentally revealed. It determines optimal conditions for sub-Poissonian light generation.
NASA Astrophysics Data System (ADS)
Scarani, Valerio; Acín, Antonio; Ribordy, Grégoire; Gisin, Nicolas
2004-02-01
We introduce a new class of quantum key distribution protocols, tailored to be robust against photon number splitting (PNS) attacks. We study one of these protocols, which differs from the original protocol by Bennett and Brassard (BB84) only in the classical sifting procedure. This protocol is provably better than BB84 against PNS attacks at zero error.
Scarani, Valerio; Acín, Antonio; Ribordy, Grégoire; Gisin, Nicolas
2004-02-01
We introduce a new class of quantum key distribution protocols, tailored to be robust against photon number splitting (PNS) attacks. We study one of these protocols, which differs from the original protocol by Bennett and Brassard (BB84) only in the classical sifting procedure. This protocol is provably better than BB84 against PNS attacks at zero error. PMID:14995344
Photon-number entangled states generation model with stimulated parametric down conversion
Oleksandr O. Gurin; Vladyslav C. Usenko; Constantin V. Usenko
2008-01-01
We address the process of generation of the photon-number entangled states of light in the stimulated nonlinear parametric down conversion process and build the simple model describing the generation, not involving the traditional parametric approximation. The motion equations for the system of pumping and two-mode outgoing field are solved for the case of the strong correlation between two modes, the
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
Extremal states for photon number and quadratures as gauges for nonclassicality
Z. Hradil; J. Rehacek; P. de la Hoz; G. Leuchs; L. L. Sanchez-Soto
2014-12-17
Rotated quadratures carry the phase-dependent information of the electromagnetic field, so they are somehow conjugate to the photon number. We analyze this noncanonical pair, finding an exact uncertatinty relation, as well as a couple of weaker inequalities obtained by relaxing some restrictions of the problem. We also find the intelligent states saturating that relation and complete their characterization by considering extra constraints on the second-order moments of the variables involved. Using these moments, we construct performance measures tailored to diagnose photon-added and Schr\\"odinger catlike states, among others.
Characteristics of Noise and Photon Statistics of Fiber Components in Electro-Optical Systems
NASA Astrophysics Data System (ADS)
Zhao, Cheng
This thesis presents a comprehensive study of the role of the fiber replicator in electro-optical systems. In the all fiber optical diagnostic system for the National Ignition Facility's DANTE data acquisition system running at 1550nm, the 8x fiber replicator was used to increase the SNR (Signal to Noise Ratio) of single-shot, electrical pulse measurements. In the system, Mach-Zehnder modulators were used to convert the electrical signals into optical signals. The fiber replicator was used to create identical copies of the optical signals. A High SNR was achieved through the averaging of these duplicated signals. Erbium-doped fiber amplifiers (EDFAs) were built to amplify the optical signals after the fiber replicator. The EDFAs applied in the DANTEEO system should have high gain, low noise, low background signals and high pulse-shape fidelity. In this thesis, we discussed the effect of different configurations and the type of Er-doped fibers on the gain and noise performance of EDFAs. We also used a simplified model for dynamic gain in EDFAs to explore the effect of the EDFA on the shape of the amplified pulse. Based on this model, the calculated pulse-shape distortions were found to be dependent on the EDFA configuration and the optical gain. We also investigated the photon statistics with the fiber replicator in a photon entanglement system. The entangled photons were created through the up-conversion and down-conversion of a Q-switch laser beam running at 1053nm. The different behavior between entangled photon and non-entangled single photons in the system with the fiber replicator are discussed.
Piacentini, F; Levi, M P; Avella, A; López, M; Kück, S; Polyakov, S V; Degiovanni, I P; Brida, G; Genovese, M
2015-04-01
Here we present a reconstruction of the positive operator-value measurement of a photon-number-resolving detector comprised of three 50?50 beam-splitters in a tree configuration, terminated with four single-photon avalanche detectors. The four detectors' outputs are processed by an electronic board that discriminates detected photon number states from 0 to 4 and implements a "smart counting" routine to compensate for dead time issues at high count rates. PMID:25831381
F. Piacentini; M. P. Levi; A. Avella; M. Lopez; S. Kueck; S. V. Polyakov; I. P. Degiovanni; G. Brida; M. Genovese
2014-12-30
Here we present a reconstruction of the Positive Operator-Value Measurement of a photon-number-resolving detector comprised of three 50:50 beamsplitters in a tree configuration, terminated with four single-photon avalanche detectors. The four detectors' outputs are processed by an electronic board that discriminates detected photon number states from 0 to 4 and implements a "smart counting" routine to compensate for dead time issues at high count rates.
Towards log-normal statistics in high Reynolds number turbulence
A. Arneodo; S. Manneville; J. F. Muzy
1998-01-01
. We report on the experimental application of a wavelet based deconvolution method that has been recently emphasized as a very\\u000a efficient tool to extract some underlying multiplicative cascade process from synthetic turbulent signals. For high Reynolds\\u000a number wind tunnel turbulence (R?? 2000), using large velocity records (about 25 × 103 integral time scales), a cascading process is identified and
Generation of a superposition of odd photon number states for quantum information networks
J. S. Neergaard-Nielsen; B. Melholt Nielsen; C. Hettich; K. Moelmer; E. S. Polzik
2006-05-10
We report on the experimental observation of quantum-network-compatible light described by a non-positive Wigner function. The state is generated by photon subtraction from a squeezed vacuum state produced by a continuous wave optical parametric amplifier. Ideally, the state is a coherent superposition of odd photon number states, closely resembling a superposition of weak coherent states (a Schroedinger cat), with the leading contribution from a single photon state in the low parametric gain limit. Light is generated in a nearly perfect spatial mode with a Fourier-limited frequency bandwidth which matches well atomic quantum memory requirements. The source is also characterized by high spectral brightness with about 10,000 and more events per second routinely generated. The generated state of light is the ultimate input state for testing quantum memories, quantum repeaters and linear optics quantum computers.
NASA Astrophysics Data System (ADS)
Jiang Graves, Yan; Jia, Xun; Jiang, Steve B.
2013-03-01
The ?-index test has been commonly adopted to quantify the degree of agreement between a reference dose distribution and an evaluation dose distribution. Monte Carlo (MC) simulation has been widely used for the radiotherapy dose calculation for both clinical and research purposes. The goal of this work is to investigate both theoretically and experimentally the impact of the MC statistical fluctuation on the ?-index test when the fluctuation exists in the reference, the evaluation, or both dose distributions. To the first order approximation, we theoretically demonstrated in a simplified model that the statistical fluctuation tends to overestimate ?-index values when existing in the reference dose distribution and underestimate ?-index values when existing in the evaluation dose distribution given the original ?-index is relatively large for the statistical fluctuation. Our numerical experiments using realistic clinical photon radiation therapy cases have shown that (1) when performing a ?-index test between an MC reference dose and a non-MC evaluation dose, the average ?-index is overestimated and the gamma passing rate decreases with the increase of the statistical noise level in the reference dose; (2) when performing a ?-index test between a non-MC reference dose and an MC evaluation dose, the average ?-index is underestimated when they are within the clinically relevant range and the gamma passing rate increases with the increase of the statistical noise level in the evaluation dose; (3) when performing a ?-index test between an MC reference dose and an MC evaluation dose, the gamma passing rate is overestimated due to the statistical noise in the evaluation dose and underestimated due to the statistical noise in the reference dose. We conclude that the ?-index test should be used with caution when comparing dose distributions computed with MC simulation.
Temperature Measurement and Phonon Number Statistics of a Nanoelectromechanical Resonator
O. P. de Sá Neto; M. C. de Oliveira; G. J. Milburn
2015-08-07
Measuring thermodynamic quantities can be easy or not, depending on the system that is being studied. For a macroscopic object, measuring temperatures can be as simple as measuring how much a column of mercury rises when in contact with the object. At the small scale of quantum electromechanical systems, such simple methods are not available and invariably detection processes disturb the system state. Here we propose a method for measuring the temperature on a suspended semiconductor membrane clamped at both ends. In this method, the membrane is mediating a capacitive coupling between two transmission line resonators (TLR). The first TLR has a strong dispersion, that is, its decaying rate is larger than its drive, and its role is to pump in a pulsed way the interaction between the membrane and the second TLR. By averaging the pulsed measurements of the quadrature of the second TLR we show how the temperature of the membrane can be determined. Moreover the statistical description of the state of the membrane, which is directly accessed in this approach is significantly improved by the addition of a Josephson Junction coupled to the second TLR.
Temperature measurement and phonon number statistics of a nanoelectromechanical resonator
NASA Astrophysics Data System (ADS)
Neto, O. P. de Sá; deOliveira, M. C.; Milburn, G. J.
2015-09-01
Measuring thermodynamic quantities can be easy or not, depending on the system that is being studied. For a macroscopic object, measuring temperatures can be as simple as measuring how much a column of mercury rises when in contact with the object. At the small scale of quantum electromechanical systems, such simple methods are not available and invariably detection processes disturb the system state. Here we propose a method for measuring the temperature on a suspended semiconductor membrane clamped at both ends. In this method, the membrane is mediating a capacitive coupling between two transmission line resonators (TLR). The first TLR has a strong dispersion, that is, its decaying rate is larger than its drive, and its role is to pump in a pulsed way the interaction between the membrane and the second TLR. By averaging the pulsed measurements of the quadrature of the second TLR we show how the temperature of the membrane can be determined. Moreover the statistical description of the state of the membrane, which is directly accessed in this approach is significantly improved by the addition of a Josephson junction coupled to the second TLR.
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.
Department of Mathematics and Statistics Colloquia Representing Numbers Using Fibonacci Variants
Arnold, Elizabeth A.
Department of Mathematics and Statistics Colloquia Representing Numbers Using Fibonacci Variants Steve Lucas, JMU Abstract: Every natural number has a unique representation as a sum of Fibonacci it more efficient using generalizations of Fibonacci numbers. Given time, we shall also see how arithmetic
Accident/Incident Statistics 2010 Number of Work/Study-Related Injuries
Accident/Incident Statistics 2010 Number of Work/Study-Related Injuries A total of 48 work students - 5 cases involved contractor A comparison of accident numbers over the past 10 years is shown in Table 1 below. Table 1. Comparison of Staff & Student Work/Study-Related Accident Numbers Lost Workdays
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…
Horikiri, Tomoyuki; Sasaki, Hideki; Wang, Haibo; Kobayashi, Takayoshi [Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST) and Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033 (Japan)
2005-07-15
We propose a high security quantum key distribution (QKD) scheme utilizing one mode of spontaneous parametric downconversion gated by a photon number resolving detector. This photon number measurement is possible by using single-photon detectors operating at room temperature and optical fibers. By post selection, the multiphoton probability in this scheme can be reduced to lower than that of a scheme using an attenuated coherent light resulting in improvement of security. Furthermore, if distillation protocol (error correction and privacy amplification) is performed, the gain will be increased. Hence a QKD system with higher security and bit rate than the laser-based QKD system can be attained using present available technologies.
James C. H. Chu; Ben Ni; Robert Kriz; V. Amod Saxena
2000-01-01
Purpose: To study the variation of computed tomography (CT) number from a simulator-based scanner and the effect of this variation on photon-dose calculations.Method and materials: CT images of a cylindrical phantom with multiple inserts were obtained using a commercially-available simulator-CT (Ximatron: Varian, Palo Alto, CA). The linear correlation coefficient and Chi-square methods were used to determine the X-ray effective energy
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.
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.
Computational Linguistics Volume 20, Number 3 Statistically-Driven Computer Grammars of English
Computational Linguistics Volume 20, Number 3 Statistically-Driven Computer Grammars of English-Driven Computer Grammars ofEnglish (henceforth SDCGE) is an edited collection, its presentation of a broad range Language, to produce a wide-coverage English parser with the aid of statistical grammar-training techniques
Attacks exploiting deviation of mean photon number in quantum key distribution and coin tossing
NASA Astrophysics Data System (ADS)
Sajeed, Shihan; Radchenko, Igor; Kaiser, Sarah; Bourgoin, Jean-Philippe; Pappa, Anna; Monat, Laurent; Legré, Matthieu; Makarov, Vadim
2015-03-01
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-Acín-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.
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.
The number distribution of neutrons and gamma photons generated in a multiplying sample
NASA Astrophysics Data System (ADS)
Enqvist, Andreas; Pázsit, Imre; Pozzi, Sara
2006-10-01
The subject of this paper is an analytical derivation of the full probability distribution of the number of neutrons and photons generated in a sample with internal multiplication by one source emission event (spontaneous fission), and its comparison with Monte Carlo calculations. We derive recursive analytic expressions for the probability distributions P(n) up to values of n=N for which the cumulative probability ?n=0NP(n) is equal to or larger than 0.99. The derivation is achieved using the symbolic computation language Mathematica. With the introduction of a modified factorial moment of the number of neutrons and gamma photons generated in fission, the resulting expressions could be brought to a formally equivalent form with those for the factorial moments of the total number of neutrons and photons generated in the sample. The results were compared to Monte Carlo calculations, and excellent agreement was found between the analytical results and the simulations. The results show that the probability distributions change with increasing sample mass in such a way that the "bulk" of the distribution changes only slightly, but a tail develops for higher n values. This tail is the main reason for the increase of the factorial moments with increasing sample mass, an effect that was observed in earlier studies.
Branching and path-deviation of positive streamers resulting from statistical photon transport
NASA Astrophysics Data System (ADS)
Xiong, Zhongmin; Kushner, Mark J.
2014-12-01
The branching and change in direction of propagation (path-deviation) of positive streamers in molecular gases such as air likely require a statistical process which perturbs the head of the streamer and produces an asymmetry in its space charge density. In this paper, the mechanisms for path-deviation and branching of atmospheric pressure positive streamer discharges in dry air are numerically investigated from the viewpoint of statistical photon transport and photoionization. A statistical photon transport model, based on randomly selected emitting angles and mean-free-path for absorption, was developed and embedded into a fluid-based plasma transport model. The hybrid model was applied to simulations of positive streamer coaxial discharges in dry air at atmospheric pressure. The results show that secondary streamers, often spatially isolated, are triggered by the random photoionization and interact with the thin space charge layer (SCL) of the primary streamer. This interaction may be partly responsible for path-deviation and streamer branching. The general process consists of random remote photo-electron production which initiates a back-traveling electron avalanche, collision of this secondary avalanche with the primary streamer and the subsequent perturbation to its SCL. When the SCL is deformed from a symmetric to an asymmetric shape, the streamer can experience an abrupt change in the direction of propagation. If the SCL is sufficiently perturbed and essentially broken, local maxima in the SCL can develop into new streamers, leading to streamer branching. During the propagation of positive streamers, this mechanism can take place repetitively in time and space, thus producing multi-level branching and more than two branches within one level.
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.
White, Andrew G.
Creation of maximally entangled photon-number states using optical fiber multiports G. J. Pryde.50.Dv, 42.50.St, 06.30.Bp There is great interest in the development of a range of nonclassical optical-photon state, NOON 1 2 N,0 eiN 0,N ), 1 within the interferometer, where the ordered pair in the kets
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.
NASA Astrophysics Data System (ADS)
Inoue, Kyo; Honjo, Toshimori
2005-04-01
A photon-number-splitting (PNS) attack against differential-phase-shift (DPS) quantum key distribution (QKD) is described. In the conventional 1984 Bennett-Brassard protocol, using weak laser light, the PNS attacks, which involve installing a lossless transmission line and blocking pulses from which extra photons cannot be picked up, impose a limit on the transmission distance. In contrast, use of a coherent pulse train in DPS QKD prevents the PNS attack and removes the distance limitation imposed by it. We carried out a DPS QKD experiment that simulated the situation where some pulses are blocked. The result showed that extra bit errors are induced in an eavesdropped condition, indicating the robustness of DPS QKD against PNS attacks.
Strong field line shapes and photon statistics from a single molecule under anomalous noise.
Sanda, Frantisek
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. PMID:19905298
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.
Gelman, Andrew
Teaching Statistics. Volume 24, Number 3, Autumn 2002 Â· 93 .Blackwell Science Ltd as a function of distance from the hole. (We found these data in the textbook by Berry (1995), and this example? This runs into problems because the probabilities are bounded between 0 and 1. What Fig 1. Success rate
Mitin, Vladimir
of spontaneous para- metric down-conversion, gated by a Photon Number Resolving (PNR) detector [1], [2]. By post of the readout circuitry for PNR detection. Results of modeling show that a high impedance amplifier placed
NASA Astrophysics Data System (ADS)
Richardson, Chris; Sabottke, Carl; Yurtsever, Ulvi; Lamas, Antia; Dowling, Jonathan; Anisimov, Petr
2012-02-01
We develop an improvement to the weak laser pulse BB84 scheme for quantum key distribution, which utilizes entanglement to improve the security of the scheme and enhance its resilience to the photon number splitting attack. This protocol relies on the non-commutation of photon phase and number to detect an eavesdropper performing quantum non-demolition measurement on number. The potential advantages and disadvantages of this scheme are compared to the coherent decoy state solution. Most entanglement based quantum key distribution schemes rely on violations of Bell's inequalities to ensure security. However, this is not the strategy that our entanglement enhanced (EE) BB84 employs here. Instead, we detect Eve by introducing an entangled quantum state into the system that is sensitive to Eve's QND measurements. This allows for a recovery of an approximately linear dependence on transmittivity for the key rate. EE BB84 shares this advantage with coherent decoy state protocols as well as schemes that utilize strong phase reference pulses to eliminate Eve's ability to send Bob vacuum signals.
NASA Astrophysics Data System (ADS)
Tsujino, Kenji; Akiba, Makoto; Sasaki, Masahide
2007-03-01
The charge-integration readout circuit was fabricated to achieve an ultralow-noise preamplifier for photoelectrons generated in an avalanche photodiode with linear mode operation at 77 K. To reduce the various kinds of noise, the capacitive transimpedance amplifier was used and consisted of low- capacitance circuit elements that were cooled with liquid nitrogen. As a result, the readout noise is equal to 3.0 electrons averaged for a period of 40 ms. We discuss the requirements for avalanche photodiodes to achieve photon-number-resolving detectors below this noise level.
Reversing the weak measurement of an arbitrary field with finite photon number
Sun, Qingqing; Al-Amri, M.; Zubairy, M. Suhail.
2009-01-01
the King Abdul Aziz City for Science and Technology ?KACST?. ?1? J. von Neumann, Mathematical Foundations of Quantum Me- chanics ?Princeton University Press, Princeton, 1955?. ?2? A. N. Korotkov, Phys. Rev. B 60, 5737 ?1999?. ?3? H. Mabuchi and P... the weak measurement of an arbitrary field with finite photon number Qingqing Sun,1,* M. Al-Amri,2 and M. Suhail Zubairy1 1Department of Physics and Institute of Quantum Studies, Texas A&M University, College Station, Texas 77843, USA 2The National...
Nie, You-Qi; Zhang, Jun Pan, Jian-Wei; Zhang, Hong-Fei; Wang, Jian; Zhang, Zhen; Ma, Xiongfeng
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.
Tsujino, Kenji; Akiba, Makoto; Sasaki, Masahide
2007-03-01
The charge-integration readout circuit was fabricated to achieve an ultralow-noise preamplifier for photoelectrons generated in an avalanche photodiode with linear mode operation at 77 K. To reduce the various kinds of noise, the capacitive transimpedance amplifier was used and consisted of low-capacitance circuit elements that were cooled with liquid nitrogen. As a result, the readout noise is equal to 3.0 electrons averaged for a period of 40 ms. We discuss the requirements for avalanche photodiodes to achieve photon-number-resolving detectors below this noise level. PMID:17304297
Statistics of scattered photons from a driven three-level emitter in a one-dimensional open space
NASA Astrophysics Data System (ADS)
Roy, Dibyendu; Bondyopadhaya, Nilanjan
2014-04-01
We derive the statistics of scattered photons from a ?- or ladder-type three-level emitter (3LE) embedded in a one-dimensional open waveguide. The weak probe photons in the waveguide are coupled to one of the two allowed transitions of the 3LE, and the other transition is driven by a control beam. This system shows electromagnetically induced transparency, which is accompanied with the Autler-Townes splitting (ATS) at a strong driving by the control beam, and some of these effects have been observed recently. We show that the nature of second-order coherence of the transmitted probe photons near two-photon resonance changes from bunching to antibunching to constant as the strength of the control beam is ramped up from zero to a higher value where the ATS appears.
Statistical Power to Detect the Correct Number of Classes in Latent Profile Analysis.
Tein, Jenn-Yun; Coxe, Stefany; Cham, Heining
2013-10-01
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
Effective atomic numbers and electron densities of bioactive glasses for photon interaction
NASA Astrophysics Data System (ADS)
Shantappa, Anil; Hanagodimath, S. M.
2015-08-01
This work was carried out to study the nature of mass attenuation coefficient of bioactive glasses for gamma rays. Bioactive glasses are a group of synthetic silica-based bioactive materials with unique bone bonding properties. In the present study, we have calculated the effective atomic number, electron density for photon interaction of some selected bioactive glasses viz., SiO2-Na2O, SiO2-Na2O-CaO and SiO2-Na2O-P2O5 in the energy range 1 keV to 100 MeV. We have also computed the single valued effective atomic number by using XMuDat program. It is observed that variation in effective atomic number (ZPI, eff) depends also upon the weight fractions of selected bioactive glasses and range of atomic numbers of the elements. The results shown here on effective atomic number, electron density will be more useful in the medical dosimetry for the calculation of absorbed dose and dose rate.
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.
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
Some Prospects for the Future Elderly Population. Statistical Reports on Older Americans, Number 3.
ERIC Educational Resources Information Center
Fowles, Donald G.
This publication brings together a large number of facts and statistics about the country's growing population of older adults. Data indicate that regardless of their economic situation, the elderly population will not only be growing rapidly in the future but will be changing rapidly as well. The trend toward early retirement coupled with longer…
Research in Official Statistics Number 1/2002 Mining spatial association rules in census data
Malerba, Donato
available to both researchers and the general public. Population and economic census information is of greatResearch in Official Statistics Number 1/2002 19 Mining spatial association rules in census data algorithm). We report the preliminary results of the application of SPADA to Stockport census data. 1
A statistical study of the relationship between the sunspot number, maximum CME speed and
A statistical study of the relationship between the sunspot number, maximum CME speed (or CME speed index) shows a cyclic behavior similar to that found for SSN and the Ap index. Our new findings are as follows. 1) Unlike the SSN, the CME speed index does not exhibit a double peak maximum. 2
Turbulence statistics for high Reynolds number rough wall turbulent boundary layers
NASA Astrophysics Data System (ADS)
Flack, Karen A.; Schultz, Michael P.
2008-11-01
The effect of Reynolds number on rough wall turbulence statistics is investigated through a series of experiments on five rough surfaces. These consist of three fine-grit sandpaper surfaces and two commercial ship bottom paints, all with a roughness height that is a very small fraction of the boundary layer thickness. Reynolds number dependence of the near wall peak in the streamwise Reynolds normal stress is well established for smooth walls, and it has been observed that this peak is destroyed in the fully rough turbulent boundary layer. Additionally, Reynolds number effects have been observed in the streamwise Reynolds stress in the log-law and outer layers for smooth walls. This Reynolds number dependence has not been tested over a wide Reynolds number range for rough walls. Results spanning a Reynolds number range of Re? = 3,000 - 30,000 will be presented.
Pion Number Fluctuations and Correlations in the Statistical System with Fixed Isospin
V. V. Begun; M. I. Gorenstein; O. A. Mogilevsky
2010-04-16
The statistical system of pions with zero total isospin is studied. The suppression effects for the average yields due to isospin conservation are the same for $\\pi^0$, $\\pi^+$ and $\\pi^-$. However, a behavior of the corresponding particle number fluctuations are different. For neutral pions there is the enhancement of the fluctuations, whereas for charged pions the isospin conservation suppresses fluctuations. The correlations between the numbers of charged and neutral pions are observed for finite systems. This causes a maximum of the total pion number fluctuations for small systems. The thermodynamic limit values for the scaled variances of neutral and charged pions are calculated. The enhancements of the fluctuations due to Bose statistics are found and discussed.
Large-photon-number extraction from individual atoms trapped in an optical lattice
Shotter, M. D. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom) and National Institute of Standards and Technology, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423 (United States)
2011-03-15
The atom-by-atom characterization of quantum gases requires the development of novel measurement techniques. One particularly promising new technique demonstrated in recent experiments uses strong fluorescent laser scattering from neutral atoms confined in a short-period optical lattice to measure the positions of individual atoms in the sample. A crucial condition for the measurements is that atomic hopping between lattice sites must be strongly suppressed despite substantial photon recoil heating. This paper models three-dimensional polarization gradient cooling of atoms trapped within a far-detuned optical lattice. The atomic dynamics are simulated using a hybrid Monte Carlo and master-equation analysis in order to predict the frequency of processes which give rise to degradation or loss of the fluorescent signal during measurements. It is shown, consistently with the experimental results, that there exists a wide parameter range in which the lifetime of strongly fluorescing isolated lattice-trapped atoms is limited by background gas collisions rather than radiative processes. In these cases the total number of scattered photons can be as large as 10{sup 8} per atom. The performance of the technique is related to relevant experimental parameters.
Validity of transition-zone dosimetry at high atomic number interfaces in megavoltage photon beams.
Das, I J; Kase, K R; Meigooni, A S; Khan, F M; Werner, B L
1990-01-01
Measurement of dose or dose perturbation factors at high atomic number interfaces are usually performed with a thin-window parallel-plate ion chamber. In a transition region, under nonequilibrium conditions, accuracy of ion chamber readings for the dose measurements has often been questioned. This paper critically analyzes the factors (stopping power ratio and charge collection) for the dose measurements at interfaces. Monte Carlo simulations were performed to investigate the secondary electron spectrum produced by photon beams and to calculate the stopping power ratios at the point of measurement. The validity of dose measurements was studied for the photon beams in the range of Co-60 gamma rays to 24-MV x rays at bone and lead interfaces with polystyrene, using thermoluminescent dosimeters, extrapolation chamber and several types of commercially available parallel-plate ion chambers. It is observed that for energies greater than 10 MV most parallel-plate chambers can be used to measure dose accurately. At lower energies, however significant differences between measured doses with different detectors were noticed. It is suggested that at high-Z interfaces and lower energies, the dose measurements should be performed with ultrathin-window parallel-plate ion chambers or extrapolation chambers. PMID:2106608
NASA Astrophysics Data System (ADS)
Petrenko, A.; Ofek, N.; Vlastakis, B.; Sun, L.; Leghtas, Z.; Heeres, R.; Sliwa, K. M.; Mirrahimi, M.; Jiang, L.; Devoret, M. H.; Schoelkopf, R. J.
2015-03-01
Realizing a working quantum computer requires overcoming the many challenges that come with coupling large numbers of qubits to perform logical operations. These include improving coherence times, achieving high gate fidelities, and correcting for the inevitable errors that will occur throughout the duration of an algorithm. While impressive progress has been made in all of these areas, the difficulty of combining these ingredients to demonstrate an error-protected logical qubit, comprised of many physical qubits, still remains formidable. With its large Hilbert space, superior coherence properties, and single dominant error channel (single photon loss), a superconducting 3D resonator acting as a resource for a quantum memory offers a hardware-efficient alternative to multi-qubit codes [Leghtas et.al. PRL 2013]. Here we build upon recent work on cat-state encoding [Vlastakis et.al. Science 2013] and photon-parity jumps [Sun et.al. 2014] by exploring the effects of sequential measurements on a cavity state. Employing a transmon qubit dispersively coupled to two superconducting resonators in a cQED architecture, we explore further the application of parity measurements to characterizing such a hybrid qubit/cat state architecture. In so doing, we demonstrate the promise of integrating cat states as central constituents of future quantum codes.
Temperature-Independent Casimir-Polder Forces Despite Large Thermal Photon Numbers
Ellingsen, Simen A. [Department of Energy and Process Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Buhmann, Stefan Yoshi; Scheel, Stefan [Quantum Optics and Laser Science, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom)
2010-06-04
We demonstrate that Casimir-Polder potentials can be entirely independent of temperature even when allowing for the relevant thermal photon numbers to become large. This statement holds for potentials that are due to low-energy transitions of a molecule placed near a plane metal surface whose plasma frequency is much larger than any atomic resonance frequencies. For a molecule in an energy eigenstate, the temperature independence is a consequence of strong cancellations between nonresonant potential components and those due to evanescent waves. For a molecule with a single dominant transition in a thermal state, upward and downward transitions combine to form a temperature-independent potential. The results are contrasted with the case of an atom whose potential exhibits a regime of linear temperature dependence. Contact with the Casimir force between a weakly dielectric and a metallic plate is made.
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.
Generating arbitrary photon-number entangled states for continuous-variable quantum informatics.
Lee, Su-Yong; Park, Jiyong; Lee, Hai-Woong; Nha, Hyunchul
2012-06-18
We propose two experimental schemes that can produce an arbitrary photon-number entangled state (PNES) in a finite dimension. This class of entangled states naturally includes non-Gaussian continuous-variable (CV) states that may provide some practical advantages over the Gaussian counterparts (two-mode squeezed states). We particularly compare the entanglement characteristics of the Gaussian and the non-Gaussian states in view of the degree of entanglement and the Einstein-Podolsky-Rosen correlation, and further discuss their applications to the CV teleportation and the nonlocality test. The experimental imperfection due to the on-off photodetectors with nonideal efficiency is also considered in our analysis to show the feasibility of our schemes within existing technologies. PMID:22714485
Real-time quantum feedback prepares and stabilizes photon number states.
Sayrin, Clément; Dotsenko, Igor; Zhou, Xingxing; Peaudecerf, Bruno; Rybarczyk, Théo; Gleyzes, Sébastien; Rouchon, Pierre; Mirrahimi, Mazyar; Amini, Hadis; Brune, Michel; Raimond, Jean-Michel; Haroche, Serge
2011-09-01
Feedback loops are central to most classical control procedures. A controller compares the signal measured by a sensor (system output) with the target value or set-point. It then adjusts an actuator (system input) to stabilize the signal around the target value. Generalizing this scheme to stabilize a micro-system's quantum state relies on quantum feedback, which must overcome a fundamental difficulty: the sensor measurements cause a random back-action on the system. An optimal compromise uses weak measurements, providing partial information with minimal perturbation. The controller should include the effect of this perturbation in the computation of the actuator's operation, which brings the incrementally perturbed state closer to the target. Although some aspects of this scenario have been experimentally demonstrated for the control of quantum or classical micro-system variables, continuous feedback loop operations that permanently stabilize quantum systems around a target state have not yet been realized. Here we have implemented such a real-time stabilizing quantum feedback scheme following a method inspired by ref. 13. It prepares on demand photon number states (Fock states) of a microwave field in a superconducting cavity, and subsequently reverses the effects of decoherence-induced field quantum jumps. The sensor is a beam of atoms crossing the cavity, which repeatedly performs weak quantum non-demolition measurements of the photon number. The controller is implemented in a real-time computer commanding the actuator, which injects adjusted small classical fields into the cavity between measurements. The microwave field is a quantum oscillator usable as a quantum memory or as a quantum bus swapping information between atoms. Our experiment demonstrates that active control can generate non-classical states of this oscillator and combat their decoherence, and is a significant step towards the implementation of complex quantum information operations. PMID:21886159
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.
Eastham, P. R.; Littlewood, P. B. [Theory of Condensed Matter Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE (United Kingdom)
2006-02-15
We consider polariton condensation in a generalized Dicke model, describing a single-mode cavity containing quantum dots, and extend our previous mean-field theory to allow for finite-size fluctuations. Within the fluctuation-dominated regime the correlation functions differ from their (trivial) mean-field values. We argue that the low-energy physics of the model, which determines the photon statistics in this fluctuation-dominated crossover regime, is that of the (quantum) anharmonic oscillator. The photon statistics at the crossover are different in the high-temperature and low-temperature limits. When the temperature is high enough for quantum effects to be neglected we recover behavior similar to that of a conventional laser. At low enough temperatures, however, we find qualitatively different behavior due to quantum effects.
Development of a Statistical Model for Seasonal Prediction of North Atlantic Hurricane Numbers
NASA Astrophysics Data System (ADS)
Davis, K.; Zeng, X.
2014-12-01
Tropical cyclones cause more financial distress to insurance companies than any other natural disaster. From 1970-2002, it is estimated that hurricanes caused 44 billion dollars in damage, greater than 2.5 times the the next costliest catastrophe. Theses damages do not go without effect. A string of major catastrophes from 1991-1994 caused nine property firms to bankrupt and caused serious financial strain on others. The public was not only affected by the loss of life and property, but the increase in tax dollars for disaster relief. Providing better seasonal predictions of North Atlantic hurricane activity farther in advance will help alleviate some of the financial strains these major catastrophes put on the nation. A statistical model was first developed by Bill Gray's team to predict the total number of hurricanes over the North Atlantic in 1984, followed by other statistical methods, dynamic modeling, and hybrid methods in recent years. However, all these methods showed little to no skill with forecasts made by June 1 in recent years. In contrast to the relatively small year-to-year change in seasonal hurricane numbers pre-1980, there has been much greater interannual changes since, especially since the year 2000. For instance, while there were very high hurricane numbers in 2005 and 2010, 2013 was one of the lowest in history. Recognizing these interdecadal changes in the dispersion of hurricane numbers, we have developed a new statistical model to more realistically predict (by June 1 each year) the seasonal hurricane number over the North Atlantic. It is based on the Multivariate ENSO Index (MEI) conditioned by the Atlantic Multidecadal Oscillation (AMO) index, the zonal wind stress and sea surface temperature over the Atlantic. It provides both the deterministic number and the range of hurricane numbers. The details of the model and its performance from 1950-2014 in comparison with other methods will be presented in our presentation.
Kabuss, Julia; Carmele, A.; Richter, M.; Chow, Weng W.; Knorr, A.
2011-01-10
This paper presents an inductive method for the microscopic description of quantum dot (QD) QED. Our description reproduces known effects up to an arbitrary accuracy, and is extendable to typical semiconductor effects, like many electron- and phonon-interactions. As an application, this method is used to theoretically examine quantum coherence phenomena and their impact on photon statistics for a ?-type semiconductor QD strongly coupled to a single mode cavity and simultaneously excited with an external laser.
Reconstruction of photon-number distribution using low-performance photon counters Guido Zambra1,2
Paris, Matteo G. A.
are still rather rare 5 . Among these, pho- tomultiplier tubes PMT's 6 and hybrid photodetectors 4 photon ionize a single atom, and the resulting charge is amplified to produce a measurable pulse in order to transform a single ionization event into a recordable pulse. Since each charge is independently
From the Law of Large Numbers to Large Deviation Theory in Statistical Physics: An Introduction
NASA Astrophysics Data System (ADS)
Cecconi, Fabio; Cencini, Massimo; Puglisi, Andrea; Vergni, Davide; Vulpiani, Angelo
This contribution aims at introducing the topics of this book. We start with a brief historical excursion on the developments from the law of large numbers to the central limit theorem and large deviations theory. The same topics are then presented using the language of probability theory. Finally, some applications of large deviations theory in physics are briefly discussed through examples taken from statistical mechanics, dynamical and disordered systems.
Mikhail Pletyukhov; Vladimir Gritsev
2015-06-23
We provide a complete and exact quantum description of coherent light scattering in a one-dimensional multi-mode transmission line coupled to a two-level emitter. Using recently developed scattering approach we discuss transmission properties, power spectrum, the full counting statistics and the entanglement entropy of transmitted and reflected states of light. Our approach takes into account spatial parameters of an incident coherent pulse as well as waiting and counting times of a detector. We describe time evolution of the power spectrum as well as observe deviations from the Poissonian statistics for reflected and transmitted fields. In particular, the statistics of reflected photons can change from sub-Poissonian to super-Poissonian for increasing values of the detuning, while the statistics of transmitted photons is strictly super-Poissonian in all parametric regimes. We study the entanglement entropy of some spatial part of the scattered pulse and observe that it obeys the area laws and that it is bounded by the maximal entropy of the effective four-level system.
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.
TEGS-CN: A Statistical Method for Pathway Analysis of Genome-wide Copy Number Profile
Huang, Yen-Tsung; Hsu, Thomas; Christiani, David C
2014-01-01
The effects of copy number alterations make up a significant part of the tumor genome profile, but pathway analyses of these alterations are still not well established. We proposed a novel method to analyze multiple copy numbers of genes within a pathway, termed Test for the Effect of a Gene Set with Copy Number data (TEGS-CN). TEGS-CN was adapted from TEGS, a method that we previously developed for gene expression data using a variance component score test. With additional development, we extend the method to analyze DNA copy number data, accounting for different sizes and thus various numbers of copy number probes in genes. The test statistic follows a mixture of X2 distributions that can be obtained using permutation with scaled X2 approximation. We conducted simulation studies to evaluate the size and the power of TEGS-CN and to compare its performance with TEGS. We analyzed a genome-wide copy number data from 264 patients of non-small-cell lung cancer. With the Molecular Signatures Database (MSigDB) pathway database, the genome-wide copy number data can be classified into 1814 biological pathways or gene sets. We investigated associations of the copy number profile of the 1814 gene sets with pack-years of cigarette smoking. Our analysis revealed five pathways with significant P values after Bonferroni adjustment (<2.8 × 10?5), including the PTEN pathway (7.8 × 10?7), the gene set up-regulated under heat shock (3.6 × 10?6), the gene sets involved in the immune profile for rejection of kidney transplantation (9.2 × 10?6) and for transcriptional control of leukocytes (2.2 × 10?5), and the ganglioside biosynthesis pathway (2.7 × 10?5). In conclusion, we present a new method for pathway analyses of copy number data, and causal mechanisms of the five pathways require further study. PMID:25452685
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.
NASA Astrophysics Data System (ADS)
Vincenti, P.; Klewicki, J.; Morrill-Winter, C.; White, C. M.; Wosnik, M.
2013-12-01
Well-resolved measurements of the streamwise velocity in zero pressure gradient turbulent boundary layers are presented for friction Reynolds numbers up to 19,670. Distinct from most studies, the present boundary layers undergo nearly a decade increase in Reynolds number solely owing to streamwise development. The profiles of the mean and variance of the streamwise velocity exhibit logarithmic behavior in accord with other recently reported findings at high Reynolds number. The inner and mid-layer peaks of the variance profile are evidenced to increase at different rates with increasing Reynolds number. A number of statistical features are shown to correlate with the position where the viscous force in the mean momentum equation loses leading order importance, or similarly, where the mean effect of turbulent inertia changes sign from positive to negative. The near-wall peak region in the 2-D spectrogram of the fluctuations is captured down to wall-normal positions near the edge of the viscous sublayer at all Reynolds numbers. The spatial extent of this near-wall peak region is approximately invariant under inner normalization, while its large wavelength portion is seen to increase in scale in accord with the position of the mid-layer peak, which resides at a streamwise wavelength that scales with the boundary layer thickness.
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.
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.
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.
Alamino, R C; Saad, D
2008-06-01
Using methods of statistical physics, we study the average number and kernel size of general sparse random matrices over Galois fields GF(q) , with a given connectivity profile, in the thermodynamical limit of large matrices. We introduce a mapping of GF(q) matrices onto spin systems using the representation of the cyclic group of order q as the q th complex roots of unity. This representation facilitates the derivation of the average kernel size of random matrices using the replica approach, under the replica-symmetric ansatz, resulting in saddle point equations for general connectivity distributions. Numerical solutions are then obtained for particular cases by population dynamics. Similar techniques also allow us to obtain an expression for the exact and average numbers of random matrices for any general connectivity profile. We present numerical results for particular distributions. PMID:18643233
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.
NASA Astrophysics Data System (ADS)
Descartes, R.; Rota, G.-C.; Euler, L.; Bernoulli, J. D.; Siegel, Edward Carl-Ludwig
2011-03-01
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 zeta-function(domination of quantum-statistics: [Pathria, Statistical-Mechanics; Huang, Statistical-Mechanics]) VS. Bernoulli-numbers/ functions. Much can be learned about statistical-physics from Euler-numbers/functions via Riemann zeta-function(s) VS. Bernoulli-numbers/functions [Conway-Guy, Book of Numbers] and about Euler-numbers/functions, via Riemann zeta-function(s) MORPHISM, VS. Bernoulli-numbers/ functions, visa versa!!! Ex.: Riemann-hypothesis PHYSICS proof PARTLY as BEQS BEC/BEA!!!
Weston, Kenneth D; Dyck, Martina; Tinnefeld, Philip; Müller, Christian; Herten, Dirk P; Sauer, Markus
2002-10-15
A simple new approach is described and demonstrated for measuring the number of independent emitters along with the fluorescence intensity, lifetime, and emission wavelength for trajectories and images of single molecules and multichromophoric systems using a single PC plug-in card for time-correlated single-photon counting. The number of independent emitters present in the detection volume can be determined using the interphoton times in a manner similar to classical antibunching experiments. In contrast to traditional coincidence analysis based on pulsed laser excitation and direct measurement of coincident photon pairs using a time-to-amplitude converter, the interphoton distances are retrieved afterward by recording the absolute arrival time of each photon with nanosecond time resolution on two spectrally separated detectors. Intensity changes that result from fluctuations of a photophysical parameter can be distinguished from fluctuations due to changes in the number of emitters (e.g., photobleaching) in single chromophore and multichromophore intensity trajectories. This is the first report to demonstrate imaging with contrast based on the number of independently emitting species within the detection volume. PMID:12403591
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.
A model independent lower limit on the number of Gamma Ray Burst hosts from repeater statistics
Anupam Singh; Mark Srednicki
1997-09-29
We present a general statistical analysis of Gamma Ray Bursts embedded in a host population. If no host generates more than one observed burst, then we show that there is a model independent lower bound on the number of hosts, $H$, of the form $H > c B^2$, where B is the number of observed bursts, and $c$ is a constant of order one which depends on the confidence level (CL) attached to the bound. An analysis by Tegmark et al. (1996) shows that the BATSE 3B catalog of 1122 bursts is consistent with no repeaters being present, and assuming that this is indeed the case, our result implies a host population with at least H=1.2x10^6 members. Without the explicit assumption of no repeaters, a Bayesian analysis based on the results of Tegmark et al. (1996) can be performed which gives the weaker bound of $H>1.7\\times 10^5$ at the 90% CL. In the light of the non-detection of identifiable hosts in the small error-boxes associated with transient counterparts to GRBs, this result gives a model independent lower bound to the number of any rare or exotic hosts. If in fact GRBs are found to be associated with a particular sub-class of galaxies, then an analysis along the lines presented here can be used to place a lower bound on the fraction of galaxies in this sub-class. Another possibility is to treat galaxy clusters (rather than individual galaxies) as the host population, provided that the angular size of each cluster considered is less than the resolution of the detector. Finally, if repeaters are ever detected in a statistically significant manner, this analysis can be readily adapted to find upper and lower limits on $H$.
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
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.
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.
Migdall, Alan
VOLUME 77, NUMBER 10 P H Y S I C A L R E V I E W L E T T E R S 2 SEPTEMBER 1996 Can Two-Photon Interference be Considered the Interference of Two Photons? T. B. Pittman,1 D. V. Strekalov,1 A. Migdall,2 M. H" experiment in which the observed two-photon entangled state interference cannot be pictured in terms
NASA Astrophysics Data System (ADS)
Hannequin, Pascal Paul
2015-06-01
Noise reduction in photon-counting images remains challenging, especially at low count levels. We have developed an original procedure which associates two complementary filters using a Wiener-derived approach. This approach combines two statistically adaptive filters into a dual-weighted (DW) filter. The first one, a statistically weighted adaptive (SWA) filter, replaces the central pixel of a sliding window with a statistically weighted sum of its neighbors. The second one, a statistical and heuristic noise extraction (extended) (SHINE-Ext) filter, performs a discrete cosine transformation (DCT) using sliding blocks. Each block is reconstructed using its significant components which are selected using tests derived from multiple linear regression (MLR). The two filters are weighted according to Wiener theory. This approach has been validated using a numerical phantom and a real planar Jaszczak phantom. It has also been illustrated using planar bone scintigraphy and myocardial single-photon emission computed tomography (SPECT) data. Performances of filters have been tested using mean normalized absolute error (MNAE) between the filtered images and the reference noiseless or high-count images. Results show that the proposed filters quantitatively decrease the MNAE in the images and then increase the signal-to-noise Ratio (SNR). This allows one to work with lower count images. The SHINE-Ext filter is well suited to high-size images and low-variance areas. DW filtering is efficient for low-size images and in high-variance areas. The relative proportion of eliminated noise generally decreases when count level increases. In practice, SHINE filtering alone is recommended when pixel spacing is less than one-quarter of the effective resolution of the system and/or the size of the objects of interest. It can also be used when the practical interest of high frequencies is low. In any case, DW filtering will be preferable. The proposed filters have been applied to nuclear medicine images but can also be used for any other kind of photon-counting images, such as x-ray and fluorescence images.
Hannequin, Pascal Paul
2015-06-01
Noise reduction in photon-counting images remains challenging, especially at low count levels. We have developed an original procedure which associates two complementary filters using a Wiener-derived approach. This approach combines two statistically adaptive filters into a dual-weighted (DW) filter. The first one, a statistically weighted adaptive (SWA) filter, replaces the central pixel of a sliding window with a statistically weighted sum of its neighbors. The second one, a statistical and heuristic noise extraction (extended) (SHINE-Ext) filter, performs a discrete cosine transformation (DCT) using sliding blocks. Each block is reconstructed using its significant components which are selected using tests derived from multiple linear regression (MLR). The two filters are weighted according to Wiener theory. This approach has been validated using a numerical phantom and a real planar Jaszczak phantom. It has also been illustrated using planar bone scintigraphy and myocardial single-photon emission computed tomography (SPECT) data. Performances of filters have been tested using mean normalized absolute error (MNAE) between the filtered images and the reference noiseless or high-count images.Results show that the proposed filters quantitatively decrease the MNAE in the images and then increase the signal-to-noise Ratio (SNR). This allows one to work with lower count images. The SHINE-Ext filter is well suited to high-size images and low-variance areas. DW filtering is efficient for low-size images and in high-variance areas. The relative proportion of eliminated noise generally decreases when count level increases. In practice, SHINE filtering alone is recommended when pixel spacing is less than one-quarter of the effective resolution of the system and/or the size of the objects of interest. It can also be used when the practical interest of high frequencies is low. In any case, DW filtering will be preferable.The proposed filters have been applied to nuclear medicine images but can also be used for any other kind of photon-counting images, such as x-ray and fluorescence images. PMID:26009552
Ma, Xuedan; Roslyak, Oleskiy; Duque, Juan G; Pang, Xiaoying; Doorn, Stephen K; Piryatinski, Andrei; Dunlap, David H; Htoon, Han
2015-07-01
Pump-dependent photoluminescence imaging and second-order photon correlation studies have been performed on individual single-walled carbon nanotubes (SWCNTs) at room temperature. These studies enable the extraction of both the exciton diffusion constant and the Auger recombination coefficient. A linear correlation between these parameters is attributed to the effect of environmental disorder in setting the exciton mean free path and capture-limited Auger recombination at this length scale. A suppression of photon antibunching is attributed to the creation of multiple spatially nonoverlapping excitons in SWCNTs, whose diffusion length is shorter than the laser spot size. We conclude that complete antibunching at room temperature requires an enhancement of the exciton-exciton annihilation rate that may become realizable in SWCNTs allowing for strong exciton localization. PMID:26182119
NASA Astrophysics Data System (ADS)
Ma, Xuedan; Roslyak, Oleskiy; Duque, Juan G.; Pang, Xiaoying; Doorn, Stephen K.; Piryatinski, Andrei; Dunlap, David H.; Htoon, Han
2015-07-01
Pump-dependent photoluminescence imaging and second-order photon correlation studies have been performed on individual single-walled carbon nanotubes (SWCNTs) at room temperature. These studies enable the extraction of both the exciton diffusion constant and the Auger recombination coefficient. A linear correlation between these parameters is attributed to the effect of environmental disorder in setting the exciton mean free path and capture-limited Auger recombination at this length scale. A suppression of photon antibunching is attributed to the creation of multiple spatially nonoverlapping excitons in SWCNTs, whose diffusion length is shorter than the laser spot size. We conclude that complete antibunching at room temperature requires an enhancement of the exciton-exciton annihilation rate that may become realizable in SWCNTs allowing for strong exciton localization.
Study of the effects of photon statistics on Thomson scattering data
Hart, G.W.; Levinton, F.M.; McNeill, D.H.
1985-12-01
A computer code has been developed which simulates the counting statistics of a Thomson scattering measurement. The scattered and background signals in each of the wavelength channels are assumed to obey Poisson statistics, and the spectral data are fitted to a Gaussian curve using a nonlinear least-squares fitting algorithm. This method should be applicable to Thomson scattering measurements in which the signal-to-noise ratio is low due to low signal or high background. Thomson scattering data from the S-1 Spheromak have been compared to this simulation, and they have been found to be in good agreement. This code has proved to be useful assessing the effects of counting statistics relative to shot-to-shot variability in producing the observed spread in the data. It was also useful for designing improvements for the S-1 Thomson scattering system, and this method would be applicable to any measurements affected by counting statistics. 5 refs., 1 fig.
Scaling Reynolds Number Dependence of Turbulence Statistics in Wall Bounded Flows
NASA Astrophysics Data System (ADS)
McMurtry, Patrick; Wei, Tie; Klewicki, Joseph; Fife, Paul
2003-11-01
In a previous presentation Wei et al. (these proceedings) presented a new four-layer structure for wall bounded turbulence flows based on an analysis of the mean momentum balance. This structure has been supported with experimental data and a multi-scale analysis (Fife et al., these proceedings). An important outcome of this analysis is the identification of a Reynolds number dependent stress gradient balance layer and a third boundary layer length scale. This length scale, the thickness of the stress gradient balance layer, provides a useful and physically meaningful length scale for scaling turbulence quantities. In particular, a velocity scale consistent with this new length scale is used to scale turbulence velocity statistics, spanwise vorticity, and bursting frequencies. This scaling is shown to be analogous to the mixed scaling used to successfully scale some turbulence quantities (E.g., DeGraff and Eaton) and provides a physical justification for the mixed scaling. This work was supported by
NASA Astrophysics Data System (ADS)
Chakraborty, Nilanjan; Lipatnikov, Andrei N.
2013-04-01
The effects of global Lewis number Le on the statistics of fluid velocity components conditional in unburned reactants and fully burned products in the context of Reynolds Averaged Navier Stokes simulations have been analysed using a Direct Numerical Simulations (DNS) database of statistically planar turbulent premixed flames with a low Damköhler number and Lewis number ranging from 0.34 to 1.2. The conditional velocity statistics extracted from DNS data have been analysed with respect to the well-known Bray-Moss-Libby (BML) expressions which were derived based on bi-modal probability density function of reaction progress variable for high Damköhler number flames. It has been shown that the Lewis number substantially affects the mean velocity and the velocity fluctuation correlation conditional in products, with the effect being particularly pronounced for low Le. As far as the mean velocity and the velocity fluctuation correlation conditional in reactants are concerned, the BML expressions agree reasonably well with the DNS data reported in the present work. Based on a priori analysis of present and previously reported DNS data, the BML expressions have been empirically modified here in order to account for Lewis number effects, and the non-bimodal distribution of reaction progress variable. Moreover, it has been demonstrated for the first time that surface averaged velocity components and Reynolds stresses conditional in unburned reactants can be modelled without invoking expressions involving the Lewis number, as these surface averaged conditional quantities remain approximately equal to their conditionally averaged counterparts in the unburned mixture.
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)
Sauer, Ursula G; Spielmann, Horst; Rusche, Brigitte
2003-01-01
In 2003, the European Commission has published its third statistical report on the numbers of laboratory animals used in the European Union, in which the data of 1999 are analysed. For the first time, with the exception of Germany, the data presented were raised on the basis of a new registration scheme. The significance of these data is limited due to deficiencies of the tables used, restricted comparability with previously raised data, and lacking relevance to the current situation. Despite this imperfect basis, the European Commission concludes in its report that there has been a significant reduction in the number of laboratory animals used in the EU compared to the previous statistics. This statement must be regarded critically as several national statistics of the last years verify that the number of laboratory animals used has in fact increased. According to the comments of various national authorities included in the report, particularly genetic engineering is responsible for the increase in animal numbers. PMID:12764546
Statistical analyses of the magnet data for the advanced photon source storage ring magnets
Kim, S.H.; Carnegie, D.W.; Doose, C.; Hogrefe, R.; Kim, K.; Merl, R.
1995-05-01
The statistics of the measured magnetic data of 80 dipole, 400 quadrupole, and 280 sextupole magnets of conventional resistive designs for the APS storage ring is summarized. In order to accommodate the vacuum chamber, the curved dipole has a C-type cross section and the quadrupole and sextupole cross sections have 180{degrees} and 120{degrees} symmetries, respectively. The data statistics include the integrated main fields, multipole coefficients, magnetic and mechanical axes, and roll angles of the main fields. The average and rms values of the measured magnet data meet the storage ring requirements.
Three-dimensional photon counting microscopy using Bayesian estimation
NASA Astrophysics Data System (ADS)
Cho, M.
2014-09-01
We present three-dimensional photon counting microscopy using Bayesian estimation. To record the light intensity information of objects in photon-starved conditions, photon counting imaging can be used. In conventional photon counting imaging, maximum likelihood estimation (MLE) or Bayesian estimation with uniform statistical parameters has been used for 3D visualization. Since MLE does not use the prior information of the estimated target, its visual quality is not enough to recognize 3D microorganisms when low number of photons is used. In addition, because Bayesian estimation with uniform statistical parameters uses fixed statistical parameters over the whole image, the estimated image seems to be image with boost-up light intensity. On the other hand, our proposed method uses the nonuniform statistical parameters for prior information of microorganisms to estimate 3D profile of them. Therefore, this method may enhance the visual quality of 3D microscopy results with low number of photons.
The Detection Statistics of Neutrons and Photons Emitted from a Fissile Sample
Eustice, Ryan
, , Imre P´azsita , Sara A. Pozzib a Department of Nuclear Engineering, Chalmers University of Technology SE-412 96 G¨oteborg, Sweden b Department of Nuclear Engineering and Radiological Sciences, University 21, 2009 #12;1. Introduction In non-destructive assay of nuclear materials, the statistics of the num
Effect of Cooperative Atomic Interactions on Photon Statistics in a Single-Mode Laser
Zubairy, M. Suhail
1979-01-01
PAST Paleontological Statistics software package PCO Principal coordinates analysis REEF Reef Environmental Education Foundation ROA Rank Order of Abundance SCUBA Self-contained underwater breathing apparatus SSH Sea surface height SST Sea surface... Figure 13. Chlorophyll-a concentration around Galápagos in Summer 2013 .................. 40 Figure 14. SSH anomalies around Galápagos in Summer 2013 ...................................... 41 Figure 15. Average SST around Galápagos in November 2013...
Hui, Y.Y.; Chang, Y.-R.; Lee, H.-Y.; Chang, H.-C. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Lim, T.-S. [Department of Physics, Tunghai University, Taichung 407, Taiwan (China); Fann Wunshain [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)
2009-01-05
The number of negatively charged nitrogen-vacancy centers (N-V){sup -} in fluorescent nanodiamond (FND) has been determined by photon correlation spectroscopy and Monte Carlo simulations at the single particle level. By taking account of the random dipole orientation of the multiple (N-V){sup -} fluorophores and simulating the probability distribution of their effective numbers (N{sub e}), we found that the actual number (N{sub a}) of the fluorophores is in linear correlation with N{sub e}, with correction factors of 1.8 and 1.2 in measurements using linearly and circularly polarized lights, respectively. We determined N{sub a}=8{+-}1 for 28 nm FND particles prepared by 3 MeV proton irradiation.
NASA Astrophysics Data System (ADS)
Aeineh, N.; Tavassoly, M. K.
2015-08-01
In this paper, we investigate the higher-order nonclassical properties of a particular class of generalized coherent states namely the deformed photon-added nonlinear coherent states (DPACS) A†m |?, f, m>. To achieve this purpose we pay attention to higher-orders of squeezing (both Hillery- and Hong-Mandel-types), sub-Poissonian statistics and anti-bunching of the mentioned states with a well-known nonlinearity function. It is shown that for enough large values of field intensity (|?|2) for a fixed N (the order of squeezing) by increasing m (the order of excitation) the degree of squeezing evaluated by Hillery and Hong-Mandel approaches increases, while for a chosen fixed value of m, by increasing N for Hillery (Hong-Mandel) type of squeezing the strength of squeezing decreases (increases). Similarly, the degree of higher-order sub-Poissonian statistics (with fixed K) becomes lower when m increases, while (with fixed m) it gets greater values when the order of sub-Poissonian K increases. At last, higher-order anti-bunching of the DPACS is evaluated, by which we established that its (always) negative values increase with increasing m, ? and l (the order of anti-bunching) individually, i.e. the degree of anti-bunching increases.
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.
Gering, Jon C.
Exchange & Visiting) 25 Ecuador 1 Ethiopia 5 Undergraduate Majors* France 8 Accounting 82 Gambia, The 1Current Statistical Information for International Students for Spring 2014 Total Number of Students Music 1 Nigeria 6 Nursing 1 Norway 1 Physics 4 Pakistan 1 Political Science 4 Saudi Arabia 3 Psychology
Gering, Jon C.
Undergraduate Majors* Egypt 1 Accounting 66 Ethiopia 2 Agricultural Science 4 France 5 Art 8 The Gambia 3Current Statistical Information for International Students for Spring 2012 Total Number of Students Mathematics 15 Kazakhstan 1 Music 1 Macedonia 1 Nursing 1 Malaysia 3 Philosophy/Religion 1 Nepal 70 Physics 8
Gering, Jon C.
Dominica 1 Graduate 11 Egypt 1 Exchange 20 Ethiopia 1 Majors/Undergraduate* Finland 1 Accounting 56 FranceCurrent Statistical Information for International Students for Spring 2011 Total Number of Students 1 Netherlands 1 Mathematics 17 Nigeria 9 Music 1 Norway 4 Nursing 5 Oman 1 Physics 20 Peru 1
Gering, Jon C.
Ethiopia 2 Senior 96 France 6 Graduate 11 Gambia, The 3 Exchange 17 Georgia 1 Majors/Undergraduate* GermanyCurrent Statistical Information for International Students for Fall 2011 Total Number of Students Linguistics 1 Russia 1 Mathematics 13 Saudi Arabia 5 Music 2 Singapore 1 Nursing 2 South Korea 8 Philosophy
Gering, Jon C.
Exchange & Visiting) 41 Ecuador 1 Ethiopia 4 Undergraduate Majors* Finland 1 Accounting 80 France 13Current Statistical Information for International Students for Fall 2013 Total Number of Students Korea South 17 Health Science 6 Lebanon 1 Justice Systems 2 Macedonia 1 Mathematics 6 Malaysia 11 Music
Gering, Jon C.
4 France 6 Undergraduate Majors* Gambia, The 1 Accounting 83 Germany 4 Agricultural Science 4 GhanaCurrent Statistical Information for International Students for Spring 2015 Total Number of Students Science 7 Nepal 37 Justice Systems 3 Netherlands 1 Mathematics 6 Nigeria 4 Music 1 Russia 1 Nursing 2
Gering, Jon C.
1 Cameroon 1 Canada 2 Undergraduate Majors* China 112 Accounting 67 Costa Rica 1 AgriculturalCurrent Statistical Information for International Students for Spring 2013 Total Number of Students 8 Israel 1 Justice Systems 2 Italy 3 Mathematics 7 Jamaica 1 Music 2 Japan 10 Physics 7 Kazakhstan 1
Gering, Jon C.
Bulgaria 2 Cameroon 1 Undergraduate Majors* Canada 2 Accounting 67 China 106 Agricultural Science 3Current Statistical Information for International Students for Fall 2012 Total Number of Students Mathematics 6 India 4 Music 2 Indonesia 2 Physics 5 Israel 1 Political Science 5 Italy 3 Psychology 9 Jamaica
High-statistics measurement of neutral-pion pair production in two-photon collisions
Uehara, S.; Adachi, I.; Dalseno, J.; Haba, J.; Itoh, R.; Iwasaki, Y.; Katayama, N.; Kichimi, H.; Krokovny, P.; Nakamura, I.; Nakao, M.; Nishida, S.; Ozaki, H.; Sakai, Y.; Suzuki, S. Y.; Uno, S.; Watanabe, Y.; Okuno, S.; Aihara, H.; Iwasaki, M.
2008-09-01
We present a high-statistics measurement of differential cross sections and the total cross section for the process {gamma}{gamma}{yields}{pi}{sup 0}{pi}{sup 0} in the kinematic range 0.6 GeV{<=}W{<=}4.0 GeV and |cos{theta}*|{<=}0.8, where W and {theta}* are the energy and pion scattering angle, respectively, in the {gamma}{gamma} center-of-mass system. Differential cross sections are fitted to obtain information on S, D{sub 0}, D{sub 2}, G{sub 0}, and G{sub 2} waves. The G waves are important above W{approx_equal}1.6 GeV. The general behavior of partial waves is studied by fitting differential cross sections in a simple parametrization where amplitudes contain resonant contributions and smooth background. The D{sub 2} wave is dominated by the f{sub 2}(1270) meson whose parameters are consistent with the current world averages. The D{sub 0} wave contains a f{sub 2}(1270) component, whose fraction is fitted. For the S wave, the f{sub 0}(980) parameters are found to be consistent with the values determined from our recent {pi}{sup +}{pi}{sup -} data. In addition to the f{sub 0}(980), the S wave prefers to have another resonance-like contribution whose parameters are obtained.
Stirling Numbers of the Second Kind and Department of Mathematics and Statistics
DeMaio, Joe
Stirling Numbers of the Second Kind and Primality Joe DeMaio Department of Mathematics Touset stephen@touset.org April 21, 2008 Abstract A Stirling number of the second kind is a combinatorial function which yields interesting number theoretic properties with regard to primality. The Stirling number
Austin, Peter C
2010-01-01
Multilevel logistic regression models are increasingly being used to analyze clustered data in medical, public health, epidemiological, and educational research. Procedures for estimating the parameters of such models are available in many statistical software packages. There is currently little evidence on the minimum number of clusters necessary to reliably fit multilevel regression models. We conducted a Monte Carlo study to compare the performance of different statistical software procedures for estimating multilevel logistic regression models when the number of clusters was low. We examined procedures available in BUGS, HLM, R, SAS, and Stata. We found that there were qualitative differences in the performance of different software procedures for estimating multilevel logistic models when the number of clusters was low. Among the likelihood-based procedures, estimation methods based on adaptive Gauss-Hermite approximations to the likelihood (glmer in R and xtlogit in Stata) or adaptive Gaussian quadrature (Proc NLMIXED in SAS) tended to have superior performance for estimating variance components when the number of clusters was small, compared to software procedures based on penalized quasi-likelihood. However, only Bayesian estimation with BUGS allowed for accurate estimation of variance components when there were fewer than 10 clusters. For all statistical software procedures, estimation of variance components tended to be poor when there were only five subjects per cluster, regardless of the number of clusters. PMID:20949128
Niederberger, Armand; Scarani, Valerio; Gisin, Nicolas
2005-04-01
In practical quantum cryptography, the source sometimes produces multiphoton pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Luetkenhaus [Phys. Rev. A 69, 042321 (2004)] that the PNS attack is not always the optimal attack when two photons are present: if errors are present in the correlations Alice-Bob and if Eve cannot modify Bob's detection efficiency, Eve gains a larger amount of information using another attack based on a 2{yields}3 cloning machine. In this work, we extend this analysis to all distances Alice-Bob. We identify a new incoherent 2{yields}3 cloning attack which performs better than those described before. Using it, we confirm that, in the presence of errors, Eve's better strategy uses 2{yields}3 cloning attacks instead of the PNS. However, this improvement is very small for the implementations of the Bennett-Brassard 1984 (BB84) protocol. Thus, the existence of these new attacks is conceptually interesting but basically does not change the value of the security parameters of BB84. The main results are valid both for Poissonian and sub-Poissonian sources.
Ye Jinwu; Zhang Cunlin
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.
NASA Astrophysics Data System (ADS)
Niederberger, Armand; Scarani, Valerio; Gisin, Nicolas
2005-04-01
In practical quantum cryptography, the source sometimes produces multiphoton pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Lütkenhaus [Phys. Rev. A 69, 042321 (2004)] that the PNS attack is not always the optimal attack when two photons are present: if errors are present in the correlations Alice-Bob and if Eve cannot modify Bob’s detection efficiency, Eve gains a larger amount of information using another attack based on a 2?3 cloning machine. In this work, we extend this analysis to all distances Alice-Bob. We identify a new incoherent 2?3 cloning attack which performs better than those described before. Using it, we confirm that, in the presence of errors, Eve’s better strategy uses 2?3 cloning attacks instead of the PNS. However, this improvement is very small for the implementations of the Bennett-Brassard 1984 (BB84) protocol. Thus, the existence of these new attacks is conceptually interesting but basically does not change the value of the security parameters of BB84. The main results are valid both for Poissonian and sub-Poissonian sources.
A SEMI-IMPLICIT SCHEME FOR STATIONARY STATISTICAL PROPERTIES OF THE INFINITE PRANDTL NUMBER MODEL
Wang, Xiaoming
Prandtl number model, uniformly dissipative scheme, Nusselt number AMS subject classifications. 65M12, 65Z, and many models for the atmosphere, ocean, weather and climate etc. The dynamics of these systems
Photon trains and lasing: The periodically pumped quantum dot Christian Wiele* and Fritz Haake
Ludwig-Maximilians-Universität, München
Photon trains and lasing: The periodically pumped quantum dot Christian Wiele* and Fritz Haake such regular pumping could entail antibunching and sub-Poissonian photon statistics. In the bad-cavity limit a train of equally spaced photons would arise. S1050-2947 98 51410-2 PACS number s : 42.50.Ct, 42.50.Lc
Yu, Alex
.D. chonghoyu@yahoo.com Website: http://www.creative-wisdom/pub/pub.html Abstract Many students share a popular scholars in evolutionary biology and genetics. While statistical procedures are widely applied by scholars. In addition, Pearson was versed in German cultural and philosophical studies (Pearson, 1938; Williams et al
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…
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;…
Estimating the number of clusters in a dataset via the Gap statistic
Robert Tibshirani; Guenther Walther; Trevor Hastie
2000-01-01
We propose a method (the \\\\Gap statistic") for estimating the numberof clusters (groups) in a set of data. The technique uses the outputof any clustering algorithm (e.g. k-means or hierarchical), comparingthe change in within cluster dispersion to that expected under an appropriatereference null distribution. Some theory is developed forthe proposal and a simulation study that shows that the Gap statisticusually
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.…
Disability Statistics in the Developing World: A Reflection on the Meanings in Our Numbers
ERIC Educational Resources Information Center
Fujiura, Glenn T.; Park, Hye J.; Rutkowski-Kmitta, Violet
2005-01-01
Background: The imbalance between the sheer size of the developing world and what little is known about the lives and life circumstances of persons with disabilities living there should command our attention. Method: International development initiatives routinely give great priority to the collection of statistical indicators yet even the most…
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)
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 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…
Diffusion approximation and short-path statistics at low to intermediate Knudsen numbers
NASA Astrophysics Data System (ADS)
Terrée, Guillaume; Blanco, Stéphane; El Hafi, Mouna; Fournier, Richard; Rolland, Julien Yves
2015-04-01
In the field of first-return statistics in bounded domains, short paths may be defined as those paths for which the diffusion approximation is inappropriate. However, general integral constraints have been identified that make it possible to address such short-path statistics indirectly by application of the diffusion approximation to long paths in a simple associated first-passage problem. This approach is exact in the zero Knudsen limit (Blanco S. and Fournier R., Phys. Rev. Lett., 97 (2006) 230604). Its generalization to the low to intermediate Knudsen range is addressed here theoretically and the corresponding predictions are compared to both one-dimension analytical solutions and three-dimension numerical experiments. Direct quantitative relations to the solution of the Schwarzschild-Milne problem are identified.
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.
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.
Chen, Jie; Wang, Yu-Ping
2014-01-01
Array comparative genomic hybridization (aCGH) provides a high-resolution and high-throughput technique for screening of copy number variations (CNVs) within the entire genome. This technique, compared to the conventional CGH, significantly improves the identification of chromosomal abnormalities. However, due to the random noise inherited in the imaging and hybridization process, identifying statistically significant DNA copy number changes in aCGH data is challenging. We propose a novel approach that uses the mean and variance change point model (MVCM) to detect CNVs or breakpoints in aCGH data sets. We derive an approximate p-value for the test statistic and also give the estimate of the locus of the DNA copy number change. We carry out simulation studies to evaluate the accuracy of the estimate and the p-value formulation. These simulation results show that the approach is effective in identifying copy number changes. The approach is also tested on fibroblast cancer cell line data, breast tumor cell line data, and breast cancer cell line aCGH data sets that are publicly available. Changes that have not been identified by the circular binary segmentation (CBS) method but are biologically verified are detected by our approach on these cell lines with higher sensitivity and specificity than CBS. PMID:19875853
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.)
PHOTONIC NANOJET PHOTONIC NANOJET
Poon, Andrew Wing On
PHOTONIC NANOJET SCANNING MICROSCOPY PHOTONIC NANOJET SCANNING MICROSCOPY Project Members: LEE Yi Final Year Project (2004 2005) #12;OVERVIEW Photonic nanojet Photonic nanojet measurement Conventional Photonic Nanojet Scanning MicroscopePhotonic Nanojet Scanning Microscope AFM tip scanning AFM tip scanning
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.
Kwiat, Paul
in quantum communications and information processing. We propose to employ an atomic vapor as the active extent on the photoelectric effect: incident photons are converted to individual photoelectrons, either signal. For example, the silicon avalanche photodiodes used in a many-photon counting experiment
Akkermans, A M; Hendriksen, C F
1999-01-01
Some of the guidelines for potency testing of vaccines issued by regulatory bodies such as the European Pharmacopoeia (EP) and WHO are detailed and stringent (e.g. EP monograph for Newcastle Disease (ND) Vaccine (inactivated)), whereas others only stipulate that the number of animals used should be sufficient to meet the required accuracy (e.g. EP monograph for Hepatitis A vaccine (inactivated)). Simulation studies in our laboratory using historical ND potency test data indicated that the number of animals specified in the monograph is too high; a considerable reduction from 10 to seven animals per group does not substantially influence the precision of the results. Multipoint models (e.g. EP monograph for Tetanus Vaccine (adsorbed)) require at least three dilutions per vaccine for testing for response linearity. However, when historical data clearly show that in the range used the response curves are linear, it is superfluous to verify this in every test. Furthermore, linearity has little priority for a valid parallel line assay calculation. A simulation study using historical Diphtheria potency test data showed that calculations using two dilutions per vaccine in relatively small groups of animals produced results comparable to those obtained from the full assay. This procedure still enables calculation of the relative potency, in contrast to the 1 + 1 method, which gives only a pass or fail result, while the number of animals required is only slightly higher. This method could be applied in cases where the 1 + 1 method fails. In conclusion, by providing guidelines on methods in which proven consistency in production and testing may be taken into account, manufacturers are more stimulated to look for other (cheaper) ways to test the potency of a vaccine using less animals. PMID:10566799
A statistical prediction of maximum value of sunspot numbers in 23rd cycle
NASA Astrophysics Data System (ADS)
Liao, Dechun; Liao, Xinhao
An attempt has been made to predict maximum of sunspot numbers (SSN) in 23rd solar cycle by using monthly smoothed and mean values series of SSN during 1823 - 1999, determinate regressive model and stochastic autoregressive model (AR). The results suggest that the maximum value of about 118+/-57 will be occurring during August 2000 - Feb. 2001 for smoothed SSN, and two maximum values of about 129+/-40 and 126+/-40 will be occurring near June and Nov. 2000 for monthly mean SSN, respectively.
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.
Sauer, Ursula G; Spielmann, Horst; Rusche, Brigitte
2005-01-01
In the beginning of the year 2005, the European Commission published the fourth statistical report on the number of laboratory animals used in the EU Member States in the year 2002. A total of 10,731,020 experimental animals was reported, the majority of which were mice, rats and fish. In comparison to 1999, the year of the previous data collection, this is an increase by over 900,000 animals, which is mainly attributed to an increased use in fish. As in the previous years, France, the United Kingdom and Germany were the Member States that reported the highest numbers of laboratory animals. 4.5 million animals were used for the development, production and quality control of products for human medicine, dentistry and veterinary medicine and 1 million animals in toxicological and safety evaluations. 3.7 million animals were used in fundamental studies, and therefore are not covered by the scope of Council Directive 86/609/EEC on the protection of laboratory animals. This regulatory gap leaving more than a third of the laboratory animals used in the European Union without protection by EU legislation is unacceptable and should be closed during a revision of the Directive. All national authorities submitted some kind of explanatory notes alongside their national tables. In the article, an extensive summary and discussion of the contents of these notes is presented. Germany, Austria, Finland report on providing financial support for the development of alternative methods. The numbers put forward in the fourth EU statistical show that such support is desperately needed. PMID:15953963
Fukuda, Daiji; Fujii, Go; Numata, Takayuki; Amemiya, Kuniaki; Yoshizawa, Akio; Tsuchida, Hidemi; Fujino, Hidetoshi; Ishii, Hiroyuki; Itatani, Taro; Inoue, Shuichiro; Zama, Tatsuya
2011-01-17
We have realized a high-detection-efficiency photon number resolving detector at an operating wavelength of about 850 nm. The detector consists of a titanium superconducting transition edge sensor in an optical cavity, which is directly coupled to an optical fiber using an approximately 300-nm gap. The gap reduces the sensitive area and heat capacity of the device, leading to high photon number resolution of 0.42 eV without sacrificing detection efficiency or signal response speed. Wavelength dependent efficiency in fiber-coupled devices, which is due to optical interference between the fiber and the device, is also decreased to less than 1% in this configuration. The overall system detection efficiency is 98%±1% at wavelengths of around 850 nm, which is the highest value ever reported in this wavelength range. PMID:21263626
NASA Astrophysics Data System (ADS)
Gu, Zetong; Lai, Zhenhua; Zhang, Xi; Yin, Jihao; DiMarzio, Charles A.
2015-03-01
Melanin is regarded as the most enigmatic pigments/biopolymers found in most organisms. We have shown previously that melanin goes through a step-wise multi-photon absorption process after the fluorescence has been activated with high laser intensity. No melanin step-wise multi-photon activation fluorescence (SMPAF) can be obtained without the activation process. The step-wise multi-photon activation fluorescence has been observed to require less laser power than what would be expected from a non-linear optical process. In this paper, we examined the power dependence of the activation process of melanin SMPAF at 830nm and 920nm wavelengths. We have conducted research using varying the laser power to activate the melanin in a point-scanning mode for multi-photon microscopy. We recorded the fluorescence signals and position. A sequence of experiments indicates the relationship of activation to power, energy and time so that we can optimize the power level. Also we explored regional analysis of melanin to study the spatial relationship in SMPAF and define three types of regions which exhibit differences in the activation process.
Andrew Sumika Huntington
2003-01-01
The goal of this research was to develop technology for building a vertical-geometry photon number amplifier (vertical PNA) that operates at a wavelength in the low-absorption window for optical fibers near 1.55 mum. An optical amplifier of this design would provide electrically-tappable low-noise polarization-independent optical amplification of laser pulses and serve as a stepping stone toward development of a tunable
PHYSICS LETTERS 3 December 1973Volume 46A, number 2 PHOTON ECHOES IN LaF3 :Nd3+ AND YAG:Nd3+*
PHYSICS LETTERS 3 December 1973Volume 46A, number 2 PHOTON ECHOES IN LaF3 :Nd3+ AND YAG:Nd3+* N been observed in calcium tungstate [I]. We compare the dependence of the echo signals in these crystals-41. The echoes were excited between the Zl and RI levels. Our samples were: LaF3:Nd3+ (0.1 atom %), CaWO,: Nd3
Photon counting spectroscopy as done with a Thomson scattering diagnostic
Den Hartog, D.J.; Ruppert, D.E.
1993-11-01
The measurement and reduction of photon counting spectral data is demonstrated within the context of a Thomson scattering diagnostic. This diagnostic contains a microchannel plate (MCP) photomultiplier tube (PMT) as the photon sensing device. The MCP PMT is not an ideal photon sensor, the loss of photoelectrons at the MCP input and the broad charge pulse distribution at the output add to the uncertainty in recorded data. Computer simulations are used to demonstrate an approach to quantification of this added uncertainty and to develop an understanding of its source; the methodology may be applicable to the development of an understanding of photon detectors other than an MCP PMT. Emphasis is placed on the Poisson statistical character of the data, because the assumption that a Gaussian probability distribution is a reasonable statistical description of photon counting data is often questionable. When the count rate is low, the product the possible number of photon counts and the probability of measurement of a single photon is usually not sufficiently large to justify Gaussian statistics. Rather, because probabilities of measurement are so low, the Poisson probability distribution best quantifies the inherent statistical fluctuations in such counting measurements. The method of maximum likelihood is applied to derive the Poisson statistics equivalent of {sub X}{sup 2}. A Poisson statistics based data fitting code is implemented using the Newton-Raphson method of multi-dimensional root finding; we also demonstrate an algorithm to estimate the uncertainties in derived quantities.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM NOUREDDINE EL KAROUI Department of Statistics will discuss the behavior of widely used statistical methods in the high-dimensional setting where the number surprising statistical phenomena occur: for instance, maximum likelihood methods are shown to be (grossly
NASA Astrophysics Data System (ADS)
Ide, Toshiki
2009-06-01
The properties of continuous-variable teleportation of single-photon states are investigated. The output state is different from the input state due to the non-maximal entanglement in the EPR beams. The photon statistics of the teleportation output are determined and the correlation between the field information ? obtained in the teleportation process and the change in photon number is discussed. The results of the output photon statistics are applied to the transmission of a qubit encoded in the polarization of a single photon. The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous variable teleportation accidentally produces clones of the original input photon. In this paper, it derives the polarization statistics of the N-photon output components and shows that they can be decomposed into an optimal cloning term and completely unpolarized noise. It is found that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.
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.
Resonant excitation and photon entanglement from semiconductor quantum dots
Ana Predojevi?
2015-03-01
In this chapter we review the use of semiconductor quantum dots as sources of quantum light. Principally, we focus on resonant two-photon excitation, which is a method that allows for on-demand generation of photon pairs. We explore the advantages of resonant excitation and present a number of measurements that were made in this excitation regime. In particular, we cover the following topics: photon statistics, coherent manipulation of the ground-excited state superposition, and generation of time-bin entangled photon pairs.
True photo-counting statistics of multiple on-off detectors
J. Sperling; W. Vogel; G. S. Agarwal
2012-02-23
We derive a closed photo-counting formula, including noise counts and a finite quantum efficiency, for photon number resolving detectors based on on-off detectors. It applies to detection schemes such as array detectors and multiplexing setups. The result renders it possible to compare the corresponding measured counting statistics with the true photon number statistics of arbitrary quantum states. The photo-counting formula is applied to the discrimination of photon numbers of Fock states, squeezed states, and odd coherent states. It is illustrated for coherent states that our formula is indispensable for the correct interpretation of quantum effects observed with such devices.
Luchowski, R.; Matveeva, E.G.; Gryczynski, I.; Terpetschnig, E.A.; Patsenker, L.; Laczko, G.; Borejdo, J.; Gryczynski, Z.
2009-01-01
Advancements in single molecule detection (SMD) continue to unfold powerful ways to study the behavior of individual and complex molecular systems in real time. SMD enables the characterization of complex molecular interactions and reveals basic physical phenomena underlying chemical and biological processes. We present here a systematic study of the quenching efficiency of Förster-type energy-transfer (FRET) for multiple fluorophores immobilized on a single antibody. We simultaneously monitor the fluorescence intensity, fluorescence lifetime, and the number of available photons before photobleaching as a function of the number of identical emitters bound to a single IgG antibody. The detailed studies of FRET between individual fluorophores reveal complex through-space interactions. In general, even for two or three fluorophores immobilized on a single protein, homo-FRET interactions lead to an overall non-linear intensity increase and shortening of fluorescence lifetime. Over-labeling of protein in solution (ensemble) results in the loss of fluorescence signal due to the self-quenching of fluorophores making it useless for assays applications. However, in the single molecule regime, over-labeling may bring significant benefits in regards to the number of available photons and the overall survival time. Our investigation reveals possibilities to significantly increase the observation time for a single macromolecule allowing studies of macromolecular interactions that are not obscured by ensemble averaging. Extending the observation time will be crucial for developing immunoassays based on single-antibody. PMID:18855695
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.
ERIC Educational Resources Information Center
Taffel, Selma
This report presents and interprets birth statistics for the United States with particular emphasis on changes that took place during the period 1970-73. Data for the report were based on information entered on birth certificates collected from all states. The majority of the document comprises graphs and tables of data, but there are four short…
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.
people would buy the drug. Assume X = Binom(n; #18; 2 ). Then f(#18; 2 j x) / #18; n x #19; #18; x 2 (1 of statistical knowledge. Example (Berger): A drug company is deciding whether or not to market a new pain reliever. Two important factors: 1. Proportion of people #18; 1 for whom the drug will be effective 2
Gilbert, R.O.; Kinnison, R.R.
1981-08-01
The commonly used procedure for estimating the Extreme Value distribution of a sequence of measurements implicitly assumes the samples are from a stationary random process. This ignores the well known systematic and cyclic trends that typically occur. Ignoring these trends tends to overestimate the magnitude of the extremes and their associated statistics. This chapter has presented a procedure for including such trends within the parameter estimation algorithm. The result is a better estimate of extreme values.
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.
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.
ERIC Educational Resources Information Center
Sullivan, Sharon G.; Grabois, Andrew; Greco, Albert N.
2003-01-01
Includes six reports related to book trade statistics, including prices of U.S. and foreign materials; book title output and average prices; book sales statistics; book exports and imports; book outlets in the U.S. and Canada; and numbers of books and other media reviewed by major reviewing publications. (LRW)
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.
NASA Astrophysics Data System (ADS)
Kurudirek, Murat; Onaran, Tayfur
2015-07-01
Effective atomic numbers (Zeff) and electron densities (Ne) of some essential biomolecules have been calculated for total electron interaction, total proton interaction and total alpha particle interaction using an interpolation method in the energy region 10 keV-1 GeV. Also, the spectrum weighted Zeff for multi-energetic photons has been calculated using Auto-Zeff program. Biomolecules consist of fatty acids, amino acids, carbohydrates and basic nucleotides of DNA and RNA. Variations of Zeff and Ne with kinetic energy of ionizing charged particles and effective photon energies of heterogeneous sources have been studied for the given materials. Significant variations in Zeff and Ne have been observed through the entire energy region for electron, proton and alpha particle interactions. Non-uniform variation has been observed for protons and alpha particles in low and intermediate energy regions, respectively. The maximum values of Zeff have found to be in higher energies for total electron interaction whereas maximum values have found to be in relatively low energies for total proton and total alpha particle interactions. When it comes to the multi-energetic photon sources, it has to be noted that the highest Zeff values were found at low energy region where photoelectric absorption is the pre-dominant interaction process. The lowest values of Zeff have been shown in biomolecules such as stearic acid, leucine, mannitol and thymine, which have highest H content in their groups. Variation in Ne seems to be more or less the same with the variation in Zeff for the given materials as expected.
NASA Astrophysics Data System (ADS)
Leon-Saval, Sergio G.; Argyros, Alexander; Bland-Hawthorn, Joss
2013-12-01
Multimode optical fibers have been primarily (and almost solely) used as "light pipes" in short distance telecommunications and in remote and astronomical spectroscopy. The modal properties of the multimode waveguides are rarely exploited and mostly discussed in the context of guiding light. Until recently, most photonic applications in the applied sciences have arisen from developments in telecommunications. However, the photonic lantern is one of several devices that arose to solve problems in astrophotonics and space photonics. Interestingly, these devices are now being explored for use in telecommunications and are likely to find commercial use in the next few years, particularly in the development of compact spectrographs. 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. Furthermore, we foreshadow future applications of this technology to the field of nanophotonics.
Berggren, Karl K.
, weight, and power [SWAP] limitations for the laser transmitter and/or receiver necessitate a trade, and combines advanced electron-beam nanofabrication techniques with comprehensive high-speed electrical LABORATORY JOURNAL VOLUME 16, NUMBER 1, 2006 Superconductivit y The phenomenon of super- conductivity
NASA Astrophysics Data System (ADS)
Allegra, Michele; Giorda, Paolo; Paris, Matteo G. A.
2010-09-01
We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: (i) non-Gaussianity is a bound for the relative entropy of entanglement and (ii) Simon’s criterion provides a reliable estimate of the separation time also for non-Gaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e., it survives longer than a non-Gaussian one, and that this may be a general feature for CV systems in Markovian channels.
Hawton, Margaret [Department of Physics, Lakehead University, Thunder Bay, Ontario, P7B 5E1 (Canada)
2010-07-15
The positive operator valued measure (POVM) for a photon counting array detector is derived and found to equal photon flux density integrated over pixel area and measurement time. Since photon flux density equals number density multiplied by the speed of light, this justifies theoretically the observation that a photon counting array provides a coarse-grained measurement of photon position. The POVM obtained here can be written as a set of projectors onto a basis of localized states, consistent with the description of photon position in a recent quantum imaging proposal [Tsang, Phys. Rev. Lett. 102, 253601 (2009)]. The wave function that describes a photon counting experiment is the projection of the photon state vector onto this localized basis. Collapse is to the electromagnetic vacuum and not to a localized state, thus violating the textbook rules of quantum mechanics but compatible with the theory of generalized observables and the nonlocalizability of an incoming photon.
Breakthroughs in Photonics 2009
Keller, Ursula
Breakthroughs in Photonics 2009 Breakthroughs in Photonics 2009 Coherent Photon Sources Ultrafast Photonics Nonlinear Photonics Terhertz Photonics Nano-Photonics Silicon Photonics Photonics Materials Bio-Photonics Magneto-Photonics Photovoltaics and Sensors Integrated Photonics Systems Photo
Characterization of photons generated in spontaneous parametric down-conversion
NASA Astrophysics Data System (ADS)
Bashkansky, Mark; Vurgaftman, Igor; Reintjes, J.
2014-05-01
Low-photon-number sources can exhibit non-classical, counterintuitive behavior that can be exploited in the developing field of quantum technology. Single photons play a special role in this arena since they represent the ultimate lowphoton- number source. They are considered an important element in various applications such as quantum key distribution, optical quantum information processing, quantum computing, intensity measurement standards, and others yet to be discovered in this developing field. True deterministic sources of single photons on demand are currently an area of intensive research, but have not been demonstrated in a practical setting. As a result, researchers commonly default to the well-established workhorse: spontaneous parametric down-conversion generating entangled signal-idler pairs. Since this source is thermal-statistical in nature, it is common to use a detected idler photon to herald the production of a signal photon. The need exists to determine the quality of the single photons generated in the heralded signal beam. Quite often, the literature reports a "heralded second-order coherence function" of the signal photons conditioned on the idler photons using readily available single-photon detectors. In this work, we examine the applicability of this technique to single-photon characterization and the consequences of the fact that the most commonly used single-photon detectors are not photon-number resolving. Our results show that this method using non-photonresolving detectors can only be used to characterize the signal-idler correlations rather than the nature of the signalphoton state alone.
ERIC Educational Resources Information Center
Coast Community Coll. District, Costa Mesa, CA.
This instructor's manual for workplace trainers contains the materials required to conduct a course in pre-statistical process control. The course consists of six lessons for workers and two lessons for supervisors that discuss the following: concepts taught in the six lessons; workers' progress in the individual lessons; and strategies for…
A Ten Year Look at Some Enrollment Statistics, 1972-1981. Research Study Number 82-3.
ERIC Educational Resources Information Center
Gold, Ben K.
Data tables and graphs illustrate trends in enrollment and student characteristics at Los Angeles City College (LACC) for the years 1972 through 1981. First, six tables present statistics on: (1) fall semester enrollment broken down according to day/evening status, sex, full-/part-time status, freshman/sophomore status, first-time/continuing…
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,…
Multi-Photon Interference and Temporal Distinguishability of Photons
Z. Y. Ou
2007-08-24
A number of recent interference experiments involving multiple photons are reviewed. These experiments include generalized photon bunching effects, generalized Hong-Ou-Mandel interference effects and multi-photon interferometry for demonstrations of multi-photon de Broglie wavelength. The multi-photon states used in these experiments are from two pairs of photons in parametric down-conversion. We find that the size of the interference effect in these experiments, characterized by the visibility of interference pattern, is governed by the degree of distinguishability among different pairs of photons. Based on this discovery, we generalize the concept of multi-photon temporal distinguishability and relate it to a number of multi-photon interference effects. Finally, we make an attempt to interpret the coherence theory by the multi-photon interference via the concept of temporal distinguishability of photons.
Photon condensation and its phase diffusion
Jiang, Longhua; Zhang, Jing; Zhang, TianCai; Zhang, CunLin
2009-01-01
Recently, several experiments successfully achieved the strong coupling of a BEC of $ N \\sim 10^{5} $ $ ^{87}Rb $ atoms to the photons inside an ultrahigh-finesse optical cavity. The strong coupling regime was also achieved with artificial atoms such as superconducting qubits inside micro-wave circuit cavity. These systems are described by the Dicke model where a single mode of photons coupled to an assembly of $ N $ atoms with the same coupling strength $ g $. In this paper, by solving the Dicke model by $ 1/ N $ expansion, we show that at the thermodynamic limit $ N = \\infty $, one can achieve the Bose-Einstein Condensation (BEC) of the cavity photons at sufficiently strong coupling $ g $. At a finite $ N $, we identify an emergent quantum phase diffusion mode inside the BEC phase and also work out many remarkable experimental consequences of this mode such as its low frequency, photon number squeezing properties and photon statistics. The photons from the BEC phase are in a number squeezed state with much ...
Statistically background-free, phase-preserving parametric up-conversion with faint light.
Cheng, Y-H; Thomay, Tim; Solomon, Glenn S; Migdall, Alan L; Polyakov, Sergey V
2015-07-13
We demonstrate up-conversion with no statistically significant background photons and a dynamic range of 15 decades. Near-infrared 920 nm photons were converted into the visible at 577 nm using periodically poled lithium niobate waveguides pumped by a 1550 nm laser. In addition to achieving statistically noiseless frequency up-conversion, we report a high degree of phase preservation (with fringe visibilities ? 0.97) at the single-photon level using an up-converting Mach-Zehnder interferometer. This background-free process opens a path to single-photon detection with no intrinsic dark count. Combined with a demonstrated photon-number preserving property of an up-converter, this work demonstrates the feasibility of noiseless frequency up-conversion of entangled photon pairs. PMID:26191926
Transfer of single photon polarization states by two-channel continuous variable teleportation
Toshiki Ide; Holger F. Hofmann
2005-11-22
Superpositions of two orthogonal single-photon polarization states are commonly used as optical qubits. If such qubits are sent by continuous variable quantum teleportation, the modifications of the qubit states due to imperfect entanglement cause an increase in the average photon number of the output state. This effect can be interpreted as an accidental quantum cloning of the single photon input. We analyze the output statistics of the single photon teleportation and derive the transfer and cloning fidelities from the equations of the polarization qubit.
Parametric Excitation of Photon-added Coherent States
NASA Astrophysics Data System (ADS)
Dodonov, V. V.; Marchiolli, M. A.; Korennoy, Ya A.; Man'ko, V. I.; Moukhin, Y. A.
1998-11-01
We study the evolution of the photon-added coherent state | ?, mrang (introduced by Agarwal and Tara [Phys. Rev. A43, 492 (1991)]) due to a time dependence of the frequency of the electromagnetic field oscillator in a cavity or a vibrational frequency of an ion inside an electromagnetic trap. We give explicit expressions for the photon distribution function, mean values and variances of the quadrature components and of the photon number, the Wigner and Q-functions, etc. We show that the parametric excitation leads to strong oscillations of the photon (phonon) distribution function and changes the subpoissonian photon statistics to the superpoissonian one. Besides, it enables to achieve a larger squeezing coefficient than in the usual squeezed states.
Soares, C G; Bright, E L; Ehrlich, M
1988-04-01
During a measurement-assurance study done with a particular type of radiation-protection dosimeter, we obtained unexpectedly poor results when several of the dosimeters were irradiated simultaneously on-phantom in a low-energy bremsstrahlung beam. The dosimeters incorporated low- and intermediate-atomic-number (Z) thermoluminescence dosimeter elements with the intermediate-Z elements under Pb filters. The response of the low-Z elements was in good agreement with the predicted response regardless of dosimeter location on the phantom, while agreement for the intermediate-Z elements was poor for some locations not coinciding with the phantom center. We have since studied the behavior of this dosimeter type and of four other types in detail by irradiating them, one at a time, on- and off-phantom, with their geometric centers displaced up to 10 cm along the vertical and horizontal axes through the center of the beam cross section. Two low-energy bremsstrahlung beams and a 137Cs gamma-ray beam were used. Variation of response to low-energy photons with on-phantom location was observed to some degree in all intermediate-Z dosimeter elements covered with high-Z filters. The reason for the observed dependence of response upon on-phantom location seems to be insufficient side shielding against phantom and filter albedo, as proved in one case, in which added shielding removed this dependence for the element immediately adjacent to the added shield. Since the effective dose equivalent to the human body is lower for lateral incidence of low-energy photons than for the same photons incident from the front or back, dosimeters incorporating high-Z filters without side shielding (and thus expected to exhibit the phenomenon) do not lend themselves to the determination of the effective dose equivalent or any quantity proportional to it by currently employed methods. A detailed study of the angular dependence of dosimeter response performed on a suitable phantom should aid in eliminating such inadequate dosimeters from practical use. PMID:3350664
NASA Astrophysics Data System (ADS)
Huntington, Andrew Sumika
The goal of this research was to develop technology for building a vertical-geometry photon number amplifier (vertical PNA) that operates at a wavelength in the low-absorption window for optical fibers near 1.55 mum. An optical amplifier of this design would provide electrically-tappable low-noise polarization-independent optical amplification of laser pulses and serve as a stepping stone toward development of a tunable amplifying wavelength converter. The vertical PNA design consists of a multiple active region (MAR) VCSEL integrated with an avalanche photodiode of the separate absorption, charge, and multiplication layer design (SACM APD): the VCSEL is intended to operate continuous wave (CW), modulated by the APD. Both components were selected for their high gain: in excess of 10 electrons out per photon in for the APD, and slightly more than 1 photon out per electron in for the MAR VCSEL under ideal circumstances. In working toward the vertical PNA, significant technical challenges were addressed: (1) Development of a long-wavelength MAR VCSEL capable of high-temperature CW operation. Although this goal was never achieved, efforts directed to this end resulted in an investigation of basic material science issues that are vital to future improvements of the device. Better DBR and active region designs were developed, the overall thermal impedance of the structure was reduced significantly, a rudimentary optical aperture compatible with InP-based materials was tested, and loss estimates for the device were put on solid ground. (2) Development of a low-noise SACM APD capable of modulating the MAR VCSEL at high speed. Here the vital relationships between growth conditions, material quality, and APD performance were established. Other achievements include demonstration of highly uniform arrays of these devices, extremely low-noise operation, and the largest area long-wavelength APDs ever reported. (3) Successful demonstration of the epitaxial integration of these two components as a functional vertical PNA. Without a MAR VCSEL capable of CW operation, a functional vertical PNA cannot be built. Nonetheless, functional APDs and VCSELs (under pulsed operation) were separately demonstrated on vertical PNA wafers, as was a basic integration scheme.
Sub-Poissonian atomic statistics in a micromaser
Rempe, G.; Walther, H. Max-Planck-Institut fuer Quantenoptik, Garching bei Muenchen )
1990-08-01
It is shown analytically that under certain experimental conditions the steady-state photon statistics of a micromaser field are directly connected to the fluctuation in number of the atoms in transition from the upper to the lower maser level under the influence of the maser field. The analytical results are compared to the results of a computer simulation of the maser process.
Chakraborty, Ranajit; Fuerst, Paul A.; Nei, Masatoshi
1980-01-01
With the aim of understanding the mechanism of maintenance of protein polymorphism, we have studied the properties of allele frequency distribution and the number of alleles per locus, using gene-frequency data from a wide range of organisms (mammals, birds, reptiles, amphibians, Drosophila and non-Drosophila invertebrates) in which 20 or more loci with at least 100 genes were sampled. The observed distribution of allele frequencies was U-shaped in all of the 138 populations (mostly species or subspecies) examined and generally agreed with the theoretical distribution expected under the mutation-drift hypothesis, though there was a significant excess of rare alleles (gene frequency, 0 ? 0.05) in about a quarter of the populations. The agreement between the mutation-drift theory and observed data was quite satisfactory for the numbers of polymorphic (gene frequency, 0.05 ? 0.95) and monomorphic (0.95 ? 1.0) alleles.—The observed pattern of allele-frequency distribution was incompatible with the prediction from the overdominance hypothesis. The observed correlations of the numbers of rare alleles, polymorphic alleles and monomorphic alleles with heterozygosity were of the order of magnitude that was expected under the mutation-drift hypothesis. Our results did not support the view that intracistronic recombination is an important source of genetic variation. The total number of alleles per locus was positively correlated with molecular weight in most of the species examined, and the magnitude of the correlation was consistent with the theoretical prediction from mutation-drift hypothesis. The correlation between molecular weight and the number of alleles was generally higher than the correlation between molecular weight and heterozygosity, as expected. PMID:17249018
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.
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.
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.
Multi-photon entanglement in high dimensions
Malik, Mehul; Huber, Marcus; Krenn, Mario; Fickler, Robert; Zeilinger, Anton
2015-01-01
Entanglement lies at the heart of quantum mechanics $-$ as a fundamental tool for testing its deep rift with classical physics, while also providing a key resource for quantum technologies such as quantum computation and cryptography. In 1987 Greenberger, Horne, and Zeilinger realized that the entanglement of more than two particles implies a non-statistical conflict between local realism and quantum mechanics. The resulting predictions were experimentally confirmed by entangling three photons in their polarization. Experimental efforts since have singularly focused on increasing the number of particles entangled, while remaining in a two-dimensional space for each particle. Here we show the experimental generation of the first multi-photon entangled state where both $-$ the number of particles and the number of dimensions $-$ are greater than two. Interestingly, our state exhibits an asymmetric entanglement structure that is only possible when one considers multi-particle entangled states in high dimensions....
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.
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 ...
The photon counting histogram in fluorescence fluctuation spectroscopy.
Chen, Y; Müller, J D; So, P T; Gratton, E
1999-01-01
Fluorescence correlation spectroscopy (FCS) is generally used to obtain information about the number of fluorescent particles in a small volume and the diffusion coefficient from the autocorrelation function of the fluorescence signal. Here we demonstrate that photon counting histogram (PCH) analysis constitutes a novel tool for extracting quantities from fluorescence fluctuation data, i.e., the measured photon counts per molecule and the average number of molecules within the observation volume. The photon counting histogram of fluorescence fluctuation experiments, in which few molecules are present in the excitation volume, exhibits a super-Poissonian behavior. The additional broadening of the PCH compared to a Poisson distribution is due to fluorescence intensity fluctuations. For diffusing particles these intensity fluctuations are caused by an inhomogeneous excitation profile and the fluctuations in the number of particles in the observation volume. The quantitative relationship between the detected photon counts and the fluorescence intensity reaching the detector is given by Mandel's formula. Based on this equation and considering the fluorescence intensity distribution in the two-photon excitation volume, a theoretical expression for the PCH as a function of the number of molecules in the excitation volume is derived. For a single molecular species two parameters are sufficient to characterize the histogram completely, namely the average number of molecules within the observation volume and the detected photon counts per molecule per sampling time epsilon. The PCH for multiple molecular species, on the other hand, is generated by successively convoluting the photon counting distribution of each species with the others. The influence of the excitation profile upon the photon counting statistics for two relevant point spread functions (PSFs), the three-dimensional Gaussian PSF conventionally employed in confocal detection and the square of the Gaussian-Lorentzian PSF for two photon excitation, is explicitly treated. Measured photon counting distributions obtained with a two-photon excitation source agree, within experimental error with the theoretical PCHs calculated for the square of a Gaussian-Lorentzian beam profile. We demonstrate and discuss the influence of the average number of particles within the observation volume and the detected photon counts per molecule per sampling interval upon the super-Poissonian character of the photon counting distribution. PMID:10388780
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.
Buratto, Steve
Photon pair correlation spectroscopy of single tetrahedraloligophenylenevinylene molecules at room the photon statistics of single tetrahedral based oligophenylenevinylene (TOPV) molecules using photon pair tetrahedral molecule contain more than one excited chromophore and emit two or more photons simultaneously
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 ...
Single-photon generation by pulsed laser in optomechanical system via photon
Wang, Wei Hua
Single-photon generation by pulsed laser in optomechanical system via photon blockade effect Liu theoretically analyzed the photon quantum statistics properties of the output field from an optomechanical system driven by different pulsed lasers. Our results show that the probability of generating a single-photon
Chow, Tze-Show (Hayward, CA)
1989-01-01
A photon calorimeter (20, 40) is provided that comprises a laminar substrate (10, 22, 42) that is uniform in density and homogeneous in atomic composition. A plasma-sprayed coating (28, 48, 52), that is generally uniform in density and homogeneous in atomic composition within the proximity of planes that are parallel to the surfaces of the substrate, is applied to either one or both sides of the laminar substrate. The plasma-sprayed coatings may be very efficiently spectrally tailored in atomic number. Thermocouple measuring junctions (30, 50, 54) are positioned within the plasma-sprayed coatings. The calorimeter is rugged, inexpensive, and equilibrates in temperature very rapidly.
Chow, Tze-Show
1988-04-22
A photon calorimeter is provided that comprises a laminar substrate that is uniform in density and homogeneous in atomic composition. A plasma-sprayed coating, that is generally uniform in density and homogeneous in atomic composition within the proximity of planes that are parallel to the surfaces of the substrate, is applied to either one or both sides of the laminar substrate. The plasma-sprayed coatings may be very efficiently spectrally tailored in atomic number. Thermocouple measuring junctions, are positioned within the plasma-sprayed coatings. The calorimeter is rugged, inexpensive, and equilibrates in temperature very rapidly. 4 figs.
Detecting photon-photon scattering in vacuum at exawatt lasers Daniele Tommasini,1
FernÃ¡ndez de CÃ³rdoba, Pedro
Detecting photon-photon scattering in vacuum at exawatt lasers Daniele Tommasini,1 Albert Ferrando for the search of photon-photon scattering in optics experiments. In particular, we show that our previous. On one hand, it has been noted that a fundamental uncertainty in the number of photons is unavoidably
Measuring the photon distribution by ON/OFF photodectors
M. Genovese; M. Gramegna; G. Brida; M. Bondani; G. Zambra; A. Andreoni; A. R. Rossi; M. G. A. Paris
2006-01-26
Reconstruction of photon statistics of optical states provide fundamental information on the nature of any optical field and find various relevant applications. Nevertheless, no detector that can reliably discriminate the number of incident photons is available. On the other hand the alternative of reconstructing density matrix by quantum tomography leads to various technical difficulties that are particular severe in the pulsed regime (where mode matching between signal an local oscillator is very challenging). Even if on/off detectors, as usual avalanche PhotoDiodes operating in Geiger mode, seem useless as photocounters, recently it was shown how reconstruction of photon statistics is possible by considering a variable quantum efficiency. Here we present experimental reconstructions of photon number distributions of both continuous-wave and pulsed light beams in a scheme based on on/off avalanche photodetection assisted by maximum-likelihood estimation. Reconstructions of the distribution for both semiclassical and quantum states of light (as single photon, coherent, pseudothermal and multithermal states) are reported for single-mode as well as for multimode beams. The stability and good accuracy obtained in the reconstruction of these states clearly demonstrate the interesting potentialities of this simple technique.
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.
Impact of Geometry on the TM Photonic Band Gaps of Photonic Crystals and Quasicrystals
Bita, Ion
Here we demonstrate a novel quantitative procedure to pursue statistical studies on the geometric properties of photonic crystals and photonic quasicrystals (PQCs) which consist of separate dielectric particles. The geometric ...
NASA Astrophysics Data System (ADS)
Yamada, Keiichi
1990-08-01
In my dissertation, first, I show that when a pair of two-level atoms are confined in a region whose linear dimension is much smaller than the resonant wavelength, the intensity fluorescence exhibits dark and bright periods. The time scale for these "macroscopic quantum jumps" is the order of the lifetime of the metastable state. The creation of this metastable state is a direct consequence of the cooperative interaction between the atoms. My analysis is based on the study of quasi-steady-state populations and frequency resolved delay functions, an extension of a concept introduced by S. Reynaud, J. Dalibard, and C. Cohen-Tannoudji (IEEE J. Quant. Elec. 24, 1395 (1988)). I also show that these concepts simplify both calculations and interpretations in many problems involving macroscopic quantum jumps. Second, I study the quantum statistical properties of the fluorescence from one two-level and two two-level atoms. The generation of sub-Poissonian light, in which the intensity fluctuations are smaller than the classical limit, is investigated. I show that the two systems considered are capable of generating sub-Poissonian light under certain conditions. My analysis is based on the frequency resolved delay functions and branching functions developed in Chapter I. My method is found to be simpler than the conventional approach which is based on second order correlation functions of the field. Third, I study pulse propagation through a nonlinear medium. The field representing the pulse is quantized and the medium is made up of randomly distributed identical two-level atoms. I show that operator versions of the Maxwell-Bloch equations with added Langevin fluctuating terms and a c-number source term correctly describe the propagation of the pulse. I solve these equations in the weak field regime and show that many results predicted by a semiclassical theory of this problem are reproduced, and that no quantum property of the field plays an important role in this regime. I also solve the same equations in the strong field regime and show that quantum noise, which is the direct manifestation of the quantized nature of the field, is created and subsequently amplified as the pulse propagates through the medium.
Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation
Ide, Toshiki; Hofmann, Holger F.
2007-06-15
The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the N-photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.
Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation
Ide, T; Hofmann, Holger F.; Ide, Toshiki
2007-01-01
The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the $N$-photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.
Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation
Toshiki Ide; Holger F. Hofmann
2007-04-05
The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the $N$-photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.
Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation
NASA Astrophysics Data System (ADS)
Ide, Toshiki; Hofmann, Holger F.
2007-06-01
The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the N -photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.
Atom de Broglie Wave Deflection by a Single Cavity Mode in the Few-Photon Limit: Quantum Prism
Domokos, P.; Adam, P.; Janszky, J. [Research Laboratory for Crystal Physics, P.O. Box 132, H-1502 Budapest (Hungary)] [Research Laboratory for Crystal Physics, P.O. Box 132, H-1502 Budapest (Hungary); Zeilinger, A. [Institut fuer Experimentalphysik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria)] [Institut fuer Experimentalphysik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria)
1996-08-01
It is shown that the deflection of an atom de Broglie wave at a nonresonant weak cavity field mode can yield a pure entangled quantum state in which discernable atomic beams are entangled to photon number states of the field and to internal states of the atom. The proposed experimental scheme is shown to be applicable for quantum nondemolition measurement of the photon statistics, and for quantum state engineering and reconstruction experiments. {copyright} {ital 1996 The American Physical Society.}
Park, Eun Sug; Symanski, Elaine; Han, Daikwon; Spiegelman, Clifford
2015-06-01
A major difficulty with assessing source-specific health effects is that source-specific exposures cannot be measured directly; rather, they need to be estimated by a source-apportionment method such as multivariate receptor modeling. The uncertainty in source apportionment (uncertainty in source-specific exposure estimates and model uncertainty due to the unknown number of sources and identifiability conditions) has been largely ignored in previous studies. Also, spatial dependence of multipollutant data collected from multiple monitoring sites has not yet been incorporated into multivariate receptor modeling. The objectives of this project are (1) to develop a multipollutant approach that incorporates both sources of uncertainty in source-apportionment into the assessment of source-specific health effects and (2) to develop enhanced multivariate receptor models that can account for spatial correlations in the multipollutant data collected from multiple sites. We employed a Bayesian hierarchical modeling framework consisting of multivariate receptor models, health-effects models, and a hierarchical model on latent source contributions. For the health model, we focused on the time-series design in this project. Each combination of number of sources and identifiability conditions (additional constraints on model parameters) defines a different model. We built a set of plausible models with extensive exploratory data analyses and with information from previous studies, and then computed posterior model probability to estimate model uncertainty. Parameter estimation and model uncertainty estimation were implemented simultaneously by Markov chain Monte Carlo (MCMC*) methods. We validated the methods using simulated data. We illustrated the methods using PM2.5 (particulate matter ? 2.5 ?m in aerodynamic diameter) speciation data and mortality data from Phoenix, Arizona, and Houston, Texas. The Phoenix data included counts of cardiovascular deaths and daily PM2.5 speciation data from 1995-1997. The Houston data included respiratory mortality data and 24-hour PM2.5 speciation data sampled every six days from a region near the Houston Ship Channel in years 2002-2005. We also developed a Bayesian spatial multivariate receptor modeling approach that, while simultaneously dealing with the unknown number of sources and identifiability conditions, incorporated spatial correlations in the multipollutant data collected from multiple sites into the estimation of source profiles and contributions based on the discrete process convolution model for multivariate spatial processes. This new modeling approach was applied to 24-hour ambient air concentrations of 17 volatile organic compounds (VOCs) measured at nine monitoring sites in Harris County, Texas, during years 2000 to 2005. Simulation results indicated that our methods were accurate in identifying the true model and estimated parameters were close to the true values. The results from our methods agreed in general with previous studies on the source apportionment of the Phoenix data in terms of estimated source profiles and contributions. However, we had a greater number of statistically insignificant findings, which was likely a natural consequence of incorporating uncertainty in the estimated source contributions into the health-effects parameter estimation. For the Houston data, a model with five sources (that seemed to be Sulfate-Rich Secondary Aerosol, Motor Vehicles, Industrial Combustion, Soil/Crustal Matter, and Sea Salt) showed the highest posterior model probability among the candidate models considered when fitted simultaneously to the PM2.5 and mortality data. There was a statistically significant positive association between respiratory mortality and same-day PM2.5 concentrations attributed to one of the sources (probably industrial combustion). The Bayesian spatial multivariate receptor modeling approach applied to the VOC data led to a highest posterior model probability for a model with five sources (that seemed to be refinery, petrochemical production, gasoline eva
Zeng, Chen
VOLUME 80, NUMBER 1 P H Y S I C A L R E V I E W L E T T E R S 5 JANUARY 1998 Statistical Topography) The statistical topography of two-dimensional interfaces in the presence of quenched disorder is studied utilizing-in-time algorithms to study the topography [7] of disordered interfaces at zero tempera- ture. In contrast
High Accuracy Calibration of Photon-Counting Detectors Sergey V. Polyakov*a
Hart, Gus
produced by parametric down-conversion. In this calibration scheme, the detection of a first photon an accurate calibration. Keywords: calibration, detector, down-conversion, correlated photons, statistical
Photonics Technology News Photonics Technology
Suslick, Kenneth S.
Photonics Technology News Photonics Technology News November 2000 Sponsored by: Color: Photonics Technology News November 2000 5/17/2010file://C:\\Documents and Settings\\Ken\\KSS Docs permission is prohibited. Page 2 of 2Color-Changing Array Identifies Odors: Photonics Technology News
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.
Auxiliary Entanglement in Photon Pairs for Multi-Photon Entanglement
Grice, Warren P [ORNL; Bennink, Ryan S [ORNL; Evans, Philip G [ORNL; Humble, Travis S [ORNL; Schaake, Jason [ORNL
2012-01-01
A growing number of experiments make use of multiple pairs of photons generated in the process of spontaneous parametric down-conversion. We show that entanglement in unwanted degrees of freedom can adversely affect the results of these experiments. We also discuss techniques to reduce or eliminate spectral and spatial entanglement, and we present results from two-photon polarization-entangled source with almost no entanglement in these degrees of freedom. Finally, we present two methods for the generation of four-photon polarization- entangled states. In one of these methods, four-photon can be generated without the need for intermediate two-photon entanglement.
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.
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.
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.
Photoelectron anticorrelations and sub-Poisson statistics in scintillation detectors
Bousselham, Abdelkader; Barrett, Harrison H.; Bora, Vaibhav; Shah, Kanai
2010-01-01
The performance of scintillation detectors for x rays and gamma rays is limited fundamentally by the statistics of the scintillation light and the resulting photoelectrons. This paper presents a new experimental approach to studying these statistics by observing correlations in the signals from two photodetectors. It is shown that the Fano factors (ratios of variance to mean), both for the number the photoelectrons produced on the photocathode of the photomultiplier and for the underlying number of scintillation photons, can be deduced from these correlations. For LaBr3(Ce) and 662 keV gamma rays, the photopeak signals obtained by photomultipliers on opposite faces of a thin sample are negatively correlated, and the Fano factor for the photoelectrons is significantly less than one. The inferred Fano factor for the optical photons is very small, indistinguishable from zero within experimental error. PMID:20725609
Lifetime statistics of quantum chaos studied by a multiscale analysis
Di Falco, A.; Krauss, T. F.; Fratalocchi, A.
2012-04-30
In a series of pump and probe experiments, we study the lifetime statistics of a quantum chaotic resonator when the number of open channels is greater than one. Our design embeds a stadium billiard into a two dimensional photonic crystal realized on a silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory with an excellent level of agreement.
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…
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…
Ben-Zion, Yehuda
VOLUME 78, NUMBER 25 P H Y S I C A L R E V I E W L E T T E R S 23 JUNE 1997 Statistics of Earthquakes in Simple Models of Heterogeneous Faults Daniel S. Fisher, Karin Dahmen, and Sharad Ramanathan 3 March 1997) Simple models for ruptures along a heterogeneous earthquake fault zone are studied
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: 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.
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.
Yamaguchi, Satoshi; Sato, Eiichi; Oda, Yasuyuki; Nakamura, Ryuji; Oikawa, Hirobumi; Yabuushi, Tomonori; Ariga, Hisanori; Ehara, Shigeru
2015-09-01
To measure X-ray spectra with high count rates, we developed a detector consisting of a Lu2(SiO4)O [LSO] crystal with a decay time of 40ns and a multipixel photon counter (MPPC). The photocurrents flowing through the MPPC are converted into voltages and amplified by a high-speed current-voltage amplifier, and event pulses from the amplifier are sent to a multichannel analyzer to measure spectra. We used three MPPCs of 100, 400 and 1600pixels/mm(2), and the MPPCs were driven under pre-Geiger mode at a temperature of 20°C. At a tube voltage of 100kV and a tube current of 5.0?A, the maximum count rate was 12.8kilo-counts per second. The event-pulse widths were 200ns, and the energy resolution was 53% at 59.5keV using a 100-pixel MPPC. PMID:26046520
Multi-photon entanglement in high dimensions
Mehul Malik; Manuel Erhard; Marcus Huber; Mario Krenn; Robert Fickler; Anton Zeilinger
2015-09-08
Entanglement lies at the heart of quantum mechanics $-$ as a fundamental tool for testing its deep rift with classical physics, while also providing a key resource for quantum technologies such as quantum computation and cryptography. In 1987 Greenberger, Horne, and Zeilinger realized that the entanglement of more than two particles implies a non-statistical conflict between local realism and quantum mechanics. The resulting predictions were experimentally confirmed by entangling three photons in their polarization. Experimental efforts since have singularly focused on increasing the number of particles entangled, while remaining in a two-dimensional space for each particle. Here we show the experimental generation of the first multi-photon entangled state where both $-$ the number of particles and the number of dimensions $-$ are greater than two. Interestingly, our state exhibits an asymmetric entanglement structure that is only possible when one considers multi-particle entangled states in high dimensions. Two photons in our state reside in a three-dimensional space, while the third lives in two dimensions. Our method relies on combining two pairs of photons, high-dimensionally entangled in their orbital angular momentum, in such a way that information about their origin is erased. Additionally, we show how this state enables a new type of "layered" quantum cryptographic protocol where two parties share an additional layer of secure information over that already shared by all three parties. In addition to their application in novel quantum communication protocols, such asymmetric entangled states serve as a manifestation of the complex dance of correlations that can exist within quantum mechanics.
Controlling photon transport in the single-photon weak-coupling regime of cavity optomechanics
Wen-Zhao Zhang; Jiong Cheng; Jing-Yi Liu; Ling Zhou
2015-07-01
We study the photon statistics properties of few-photon transport in an optomechanical system where an optomechanical cavity couples to two empty cavities. By analytically deriving the one- and two-photon currents in terms of a zero-time-delayed two-order correlation function, we show that a photon blockade can be achieved in both the single-photon strong-coupling regime and the single-photon weak-coupling regime due to the nonlinear interacting and multipath interference. Furthermore, our systems can be applied as a quantum optical diode, a single-photon source, and a quantum optical capacitor. It is shown that this the photon transport controlling devices based on photon antibunching does not require the stringent single-photon strong-coupling condition. Our results provide a promising platform for the coherent manipulation of optomechanics, which has potential applications for quantum information processing and quantum circuit realization.
Pázsit, Imre
2006-01-01
Nuclear Instruments and Methods in Physics Research A 566 (2006) 598608 The number distribution studied both with analytical methods and Monte Carlo simulations in the past. These studies are motivated
Evans, Joshua D. Yu, Yaduo; Williamson, Jeffrey F.; Whiting, Bruce R.; O’Sullivan, Joseph A.; Politte, David G.; Klahr, Paul H.
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.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM JEROME FRIEDMAN Department of Statistics Stanford Ensemble methods have emerged as being among the most powerful statistical learning techniques. It is shown
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM GOURAB MUKHERJEE Department of Statistics Stanford directions in statistical probability forecasting. Building on these parallels we present a frequentist
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM ADRIAN RAFTERY Department of Statistics University will describe a Bayesian statistical method for probabilistic population projections for all countries
Quantum Interference Induced Photon Blockade in a Coupled Single Quantum Dot-Cavity System
Jing Tang; Weidong Geng; Xiulai Xu
2015-03-18
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.
Quantum Interference Induced Photon Blockade in a Coupled Single Quantum Dot-Cavity System
Tang, Jing; 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 in...
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
Exciton-photon correlations in bosonic condensates of exciton-polaritons
NASA Astrophysics Data System (ADS)
Kavokin, Alexey V.; Sheremet, Alexandra S.; Shelykh, Ivan A.; Lagoudakis, Pavlos G.; Rubo, Yuri G.
2015-07-01
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a statistical model describing stochastic exciton-photon transitions within a condensate of exciton polaritons. We show that the exciton-photon correlator depends on the rate of incoherent exciton-photon transformations in the condensate. We discuss implications of this effect for the quantum statistics of photons emitted by polariton lasers.
Hansen, John P
2004-01-01
Healthcare quality professionals need to understand and use inferential statistics to interpret sample data from their organizations. Since in quality improvement and healthcare research studies, all the data from a population often are not available, investigators take samples and make inferences about that population using inferential statistics. This series of six articles will give readers an understanding of the concepts of inferential statistics, as well as the specific tools for calculating confidence intervals and tests of statistical significance for samples of data. The statistical principles are equally applicable to quality improvement and healthcare research studies. This article, Part 4, starts with a review of the information contained in Parts 1, 2, and 3, which appeared in the July/August 2003 issue of the Journal for Healthcare Quality. This article describes t distributions and how these are used to calculate confidence intervals for estimating a population mean based on a sample mean of a continuous variable. Part 4 concludes with a discussion of standard error, margin of error, and confidence intervals for estimating a population proportion based on a sample proportion from a binomial variable. PMID:15352342
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 3, describes standard error and margin of error for a continuous variable and how they are calculated from the sample size and standard deviation of a sample. The article then demonstrates how the standard error and margin of error are used to calculate the confidence interval for estimating a population mean based on a sample mean. PMID:14606211
Two photon amplitude of partially coherent partially entangled electromagnetic fields
Miguel Angel Olvera; Sonja Franke-Arnold
2015-07-30
The development of efficient protocols for pure and mixed states preparation is challenging task. Most of the theory of quantum information applications has been developed for fully coherent or completely incoherent light. However, in many situations of interest partially coherent light has been proved to be a more robust model of radiation. In this paper the underpinning theory of two photon amplitude functions for down-converted fields with partially coherent pump beams is investigated. By using the generalised Siegert relations and the coherent mode representation of the cross spectral density matrix the two photon amplitude is fully characterised for partially coherent beams. A number of correlation properties from modern coherence theory are demonstrated to be preserved under parametric down-conversion. Based on the generalised Siegert relations and the Cauchy-Schwarz inequality a measure of entanglement for the two photon amplitude is proposed. Upper bounds for this measure are found in terms of the \\emph{golden ratio} for maximally entangled states. Two inequalities are derived for the two photon amplitude for which there exist a transition zone from super-Poisson statistics to sub-Poisson statistics for down-converted partially coherent fields.
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.
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…
Blennerhassett, Peter
August for Semester 2. Before the census date students are able to drop courses themselves through my, this can be applied for on-line through MyUNSW at the following address http://iaro.online Home Page on the School of Mathematics and Statistics web site. http
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.
Photonic Astronomy and Quantum Optics
Dravins, Dainis
2015-01-01
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.
Closed baryonic Universe from photon cooling
NASA Technical Reports Server (NTRS)
Bartlett, J. G.; Hall, L. J.
1991-01-01
The Universe may be critically closed by baryons and not conflict with standard big-bang nucleosynthesis if the comoving number density of photons is reduced after nucleosynthesis. This is accomplished at a temperature of order 10 keV by recoupling the photons to a cold hidden sector via a photon-mixing mechanism. Signatures from supernovae, neutrino backgrounds, and nucleosynthesis are discussed.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM DAVID BLEI Department of Statistics and Computer posterior inference algorithms have revolutionized Bayesian statistics, revealing its potential as a usable and general-purpose language for data analysis. Bayesian statistics, however, has not yet reached
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.
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,...
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.
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.
Spectral x-ray diffraction using a 6 megapixel photon counting array detector
NASA Astrophysics Data System (ADS)
Muir, Ryan D.; Pogranichniy, Nicholas R.; Muir, J. Lewis; Sullivan, Shane Z.; Battaile, Kevin P.; Mulichak, Anne M.; Toth, Scott J.; Keefe, Lisa J.; Simpson, Garth J.
2015-03-01
Pixel-array array detectors allow single-photon counting to be performed on a massively parallel scale, with several million counting circuits and detectors in the array. Because the number of photoelectrons produced at the detector surface depends on the photon energy, these detectors offer the possibility of spectral imaging. In this work, a statistical model of the instrument response is used to calibrate the detector on a per-pixel basis. In turn, the calibrated sensor was used to perform separation of dual-energy diffraction measurements into two monochromatic images. Targeting applications include multi-wavelength diffraction to aid in protein structure determination and X-ray diffraction imaging.
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
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.
M. Fanfoni; M. Tomellini
2015-05-19
An "experimental" study on the randomness of the fractional digits of $\\pi$, $e$ and $\\phi$ irrational numbers are presented. This is done by exploiting the $1D$ Poisson-Voronoi tessellation. We employed two approaches and in both cases, within the numerical error, no differences have been detected between the irrational fractional digits and an equivalent random sequence of digits. The number of tested digits is $1.6 \\times 10^7$ and $4 \\times 10^7$ for the first and second approach, respectively. Although not shown here, we investigated several irrational numbers and all of them have displayed a similar behavior.
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.
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)
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.
Photon Statistics in Multi-Photon Absorption and Emission Processes
Zubairy, M. Suhail; Yeh, J. J.
1980-01-01
graph. Next, we de ne a special constant which nodes can use as \\parent" if the link to their current parent goes down. is special in that for any node j, is not considered to be an adjacent node by j. (That is, saying a node's parent is is a... mechanism to correct the parent pointer. In [3, 4], if j was informed that it had an invalid parent, j would immediately color itself red and inform all of its neighbors of the change. Instead of directly adapting the mechanism proposed by [3, 4] to deal...
15 CFR 30.61 - Statistical classification schedules.
Code of Federal Regulations, 2011 CFR
2011-01-01
...requirements and 10-digit statistical reporting numbers to...United States Annotated for Statistical Reporting , shows the 10-digit statistical reporting number to be...U.S. Foreign Trade Statistics. (d) Schedule D...
15 CFR 30.61 - Statistical classification schedules.
Code of Federal Regulations, 2013 CFR
2013-01-01
...requirements and 10-digit statistical reporting numbers to...United States Annotated for Statistical Reporting , shows the 10-digit statistical reporting number to be...U.S. Foreign Trade Statistics. (d) Schedule D...
Lu, Ling
The application of topology, the mathematics of conserved properties under continuous deformations, is creating a range of new opportunities throughout photonics. This field was inspired by the discovery of topological ...
NASA Astrophysics Data System (ADS)
Eggleton, Benjamin J.; Luther-Davies, Barry; Richardson, Kathleen
2011-03-01
The unique and striking material properties of chalcogenide glasses have been studied for decades, providing applications in the electronics industry, imaging and more recently in photonics. This Review summarizes progress in photonic devices that exploit the unique optical properties of chalcogenide glasses for a range of important applications, focusing on recent examples in mid-infrared sensing, integrated optics and ultrahigh-bandwidth signal processing.
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.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM Joint seminar with Stevanovich Center PHILIPPE RIGOLLET Operations Research and Financial Engineering, Princeton University The Statistical Price to Pay ABSTRACT Computational limitations of statistical problems have largely been ignored or simply over- come
Photonic module: An on-demand resource for photonic entanglement
Devitt, Simon J.; Greentree, Andrew D.; Hollenberg, Lloyd C. L.; Ionicioiu, Radu; O'Brien, Jeremy L.; Munro, William J.
2007-11-15
Photonic entanglement has a wide range of applications in quantum computation and communication. Here we introduce a device: the photonic module, which allows for the rapid, deterministic preparation of a large class of entangled photon states. The module is an application independent, ''plug and play'' device, with sufficient flexibility to prepare entanglement for all major quantum computation and communication applications in a completely deterministic fashion without number-discriminated photon detection. We present two alternative constructions for the module, one using free-space components and one in a photonic band-gap structure. The natural operation of the module is to generate states within the stabilizer formalism and we present an analysis on the cavity requirements to experimentally realize this device.
Tailored quantum statistics from broadband states of light
S. Hartmann; F. Friedrich; A. Molitor; M. Reichert; W. Elsäßer; R. Walser
2014-12-19
We analyze the statistics of photons originating from amplified spontaneous emission generated by a quantum dot superluminescent diode. Experimentally detectable emission properties are taken into account by parametrizing the corresponding quantum state as a multi-mode phase-randomized Gaussian density operator. The validity of this model is proven in two subsequent experiments using fast two-photon-absorption detection observing second order equal-time- as well as second order fully time-resolved intensity correlations on femtosecond timescales. In the first experiment, we study the photon statistics when the number of contributing longitudinal modes is systematically reduced by applying well-controlled optical feedback. In a second experiment, we add coherent light from a single-mode laserdiode to quantum dot superluminescent diode broadband radiation. Tuning the power ratio, we realize tailored second order correlations ranging from Gaussian to Poissonian statistics. Both experiments are very well matched by theory, thus giving first insights into quantum properties of radiation from quantum dot superluminescent diodes.
NASA Astrophysics Data System (ADS)
Vigneron, Jean Pol; Simonis, Priscilla
2012-10-01
Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.
Balasubramonian, Rajeev (Sandy, UT); Dwarkadas, Sandhya (Rochester, NY); Albonesi, David (Ithaca, NY)
2009-02-10
In a processor having multiple clusters which operate in parallel, the number of clusters in use can be varied dynamically. At the start of each program phase, the configuration option for an interval is run to determine the optimal configuration, which is used until the next phase change is detected. The optimum instruction interval is determined by starting with a minimum interval and doubling it until a low stability factor is reached.
Zheng Weikang; Akerlof, Carl W.; McKay, Timothy A.; Pandey, Shashi B.; Zhang Binbin; Zhang Bing; Sakamoto, Takanori
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.
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
MEASURING TEMPORAL PHOTON BUNCHING IN BLACKBODY RADIATION
Tan, P. K.; Poh, H. S.; Kurtsiefer, C. [Center for Quantum Technologies, 3 Science Drive 2, 117543 (Singapore); Yeo, G. H.; Chan, A. H., E-mail: pengkian@physics.org, E-mail: phyck@nus.edu.sg [Department of Physics, National University of Singapore, 2 Science Drive 3, 117551 (Singapore)
2014-07-01
Light from thermal blackbody radiators such as stars exhibits photon bunching behavior at sufficiently short timescales. However, with available detector bandwidths, this bunching signal is difficult to observe directly. We present an experimental technique to increase the photon bunching signal in blackbody radiation via spectral filtering of the light source. Our measurements reveal strong temporal photon bunching from blackbody radiation, including the Sun. This technique allows for an absolute measurement of the photon bunching signature g {sup (2)}(0), and thereby a direct statement on the statistical nature of a light source. Such filtering techniques may help revive the interest in intensity interferometry as a tool in astronomy.
Engineered quantum dot single-photon sources
NASA Astrophysics Data System (ADS)
Buckley, Sonia; Rivoire, Kelley; Vu?kovi?, Jelena
2012-12-01
Fast, high efficiency and low error single-photon sources are required for the implementation of a number of quantum information processing applications. The fastest triggered single-photon sources to date have been demonstrated using epitaxially grown semiconductor quantum dots (QDs), which can be conveniently integrated with optical microcavities. Recent advances in QD technology, including demonstrations of high temperature and telecommunications wavelength single-photon emission, have made QD single-photon sources more practical. Here we discuss the applications of single-photon sources and their various requirements, before reviewing the progress made on a QD platform in meeting these requirements.
Engineered Quantum Dot Single Photon Sources
Sonia Buckley; Kelley Rivoire; Jelena Vuckovic
2012-10-03
Fast, high efficiency, and low error single photon sources are required for implementation of a number of quantum information processing applications. The fastest triggered single photon sources to date have been demonstrated using epitaxially grown semiconductor quantum dots (QDs), which can be conveniently integrated with optical microcavities. Recent advances in QD technology, including demonstrations of high temperature and telecommunications wavelength single photon emission, have made QD single photon sources more practical. Here we discuss the applications of single photon sources and their various requirements, before reviewing the progress made on a quantum dot platform in meeting these requirements.
Park, Namkyoo
PHOTONICS-2008: International Conference on Fiber Optics and Photonics December 13-17, 2008, IIT interferometer based optical multilevel DPSK receivers could be made statistically uncorrelated, statistically theoretically demonstrate the application of TCM to optical Differential Quadrature Phase Shift Keyed (DQPSK
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…
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
Photonic Floquet topological insulators.
Rechtsman, Mikael C; Zeuner, Julia M; Plotnik, Yonatan; Lumer, Yaakov; Podolsky, Daniel; Dreisow, Felix; Nolte, Stefan; Segev, Mordechai; Szameit, Alexander
2013-04-11
Topological insulators are a new phase of matter, with the striking property that conduction of electrons occurs only on their surfaces. In two dimensions, electrons on the surface of a topological insulator are not scattered despite defects and disorder, providing robustness akin to that of superconductors. Topological insulators are predicted to have wide-ranging applications in fault-tolerant quantum computing and spintronics. Substantial effort has been directed towards realizing topological insulators for electromagnetic waves. One-dimensional systems with topological edge states have been demonstrated, but these states are zero-dimensional and therefore exhibit no transport properties. Topological protection of microwaves has been observed using a mechanism similar to the quantum Hall effect, by placing a gyromagnetic photonic crystal in an external magnetic field. But because magnetic effects are very weak at optical frequencies, realizing photonic topological insulators with scatter-free edge states requires a fundamentally different mechanism-one that is free of magnetic fields. A number of proposals for photonic topological transport have been put forward recently. One suggested temporal modulation of a photonic crystal, thus breaking time-reversal symmetry and inducing one-way edge states. This is in the spirit of the proposed Floquet topological insulators, in which temporal variations in solid-state systems induce topological edge states. Here we propose and experimentally demonstrate a photonic topological insulator free of external fields and with scatter-free edge transport-a photonic lattice exhibiting topologically protected transport of visible light on the lattice edges. Our system is composed of an array of evanescently coupled helical waveguides arranged in a graphene-like honeycomb lattice. Paraxial diffraction of light is described by a Schrödinger equation where the propagation coordinate (z) acts as 'time'. Thus the helicity of the waveguides breaks z-reversal symmetry as proposed for Floquet topological insulators. This structure results in one-way edge states that are topologically protected from scattering. PMID:23579677
ERIC Educational Resources Information Center
Sullivan, Sharon G.; Barr, Catherine; Grabois, Andrew
2002-01-01
Includes six articles that report on prices of U.S. and foreign published materials; book title output and average prices; book sales statistics; book exports and imports; book outlets in the U.S. and Canada; and review media statistics. (LRW)
Cancer Statistics Cancer has a major impact on society in the United States and across the world. Cancer statistics ... prognosis, see the Understanding Cancer Prognosis page. Cancer Statistics | Did You Know? View this video on YouTube. ...
NASA Astrophysics Data System (ADS)
Quan, Frederic
2012-02-01
Photonics, the broad merger of electronics with the optical sciences, encompasses such a wide swath of technology that its impact is almost universal in our everyday lives. This is a broad overview of some aspects of the industry and their contribution to the ‘green’ or environmental movement. The rationale for energy conservation is briefly discussed and the impact of photonics on our everyday lives and certain industries is described. Some opinions from industry are presented along with market estimates. References are provided to some of the most recent research in these areas.
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
Black-body photon clustering by semi-classical means
J. P. Lestone
2008-04-20
If stimulated emission could be turned off then only uncorrelated photons would be emitted from black bodies and the photon counting statistics would be Poissonian. Through the process of stimulated emission, some fraction of the photons emitted from a black body are correlated and thus emitted in clusters. This photon clustering can be calculated by semi-classical means. The corresponding results are in agreement with quantum theory.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM PO-LING LOH Department of Statistics University the seminar in Eckhart 110 ABSTRACT Noisy and missing data are prevalent in many real-world statistical, and provide theoretical guarantees for the statistical consistency of our methods. Although our estimators
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
32. Statistics 1 32. STATISTICS
Masci, Frank
32. Statistics 1 32. STATISTICS Revised September 2007 by G. Cowan (RHUL). This chapter gives an overview of statistical methods used in High Energy Physics. In statistics, we are interested in using's validity or to determine the values of its parameters. There are two main approaches to statistical
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM SAYAN MUKHERJEE Department of Statistical Science vignettes where topological ideas are explored in statistical models of complex traits, machine learning such as sufficient statistics and dictionary learning will be touched on. I will describe an application
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM ERNST WIT Statistics and Probability University devices collect a lot of information, typically about few independent statistical subjects or units statistics. In certain special cases the method can be tweaked to obtain L1-penalized GLM solution paths
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM GONGJUN XU Department of Statistics Columbia University Statistical Inference for Diagnostic Classification Models MONDAY, February 18, 2013 at 4:00 PM-driven construction (estimation) of the Q-matrix and related statistical issues of DCMs. I will first give
Generalized quantum interference of correlated photon pairs.
Kim, Heonoh; Lee, Sang Min; Moon, Han Seb
2015-01-01
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. PMID:25951143
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.
Toward Photon-Efficient Key Distribution Over Optical Channels
Kochman, Yuval
This paper considers the distribution of a secret key over an optical (bosonic) channel in the regime of high photon efficiency, i.e., when the number of secret key bits generated per detected photon is high. While, in ...
NASA Astrophysics Data System (ADS)
Milan, D. J.; Heritage, G. L.
2007-12-01
Water flow level in river channels is moderated by the interaction with the roughness of the surface over which it flows. The interaction is highly complex and remains poorly understood despite its economic and social importance in flood level forecasting. The empirical and semi-rational nature of approaches used to estimate hydraulic roughness makes them very difficult to apply and much of the hydraulic resistance has been attributed to grain roughness using various forms of the Colebrook-White equation where the grain diameter is modified by a multiplier to account for the non-uniform nature of gravel-bed surfaces. Fundamental to the accuracy of the particle size approaches is the sampling of river-bed gravels where sample size, operator bias, particle shape and surface heterogeneity can greatly affect the result. Despite these problems a standard surface sample of the intermediate axis of 100 clasts remains the accepted method for grain-size characterisation amongst scientists and engineers concerned with channel hydraulics. Surface roughness has also been measured using a random field of spatial elevation data. The success of this approach has been tempered by the lack of high-resolution topographic data covering all roughness scales, however, improved data-point resolution is now achievable using terrestrial laser scanning technology. The aim here is to reliably quantify the population grain-size distribution of a natural gravel surface using random field terrestrial laser scanner x,y,z data and by direct comparison to demonstrate the errors inherent in the conventional particle-size approach. Application of the random field approach, using a terrestrial laser scanner, across a gravel bar surface on the River South Tyne at Lambley, UK, generated an effective sample of 120,000 clasts yielding a D84 for use in the Colebrook White equation of 0.110m. Monte Carlo sampling within the 12000 measured clasts from the bar surface generated 560 simulated grid-by-number D84 estimates. Grain-size D84 values ranged from 0.100m to 0.195m with a median value of 0.130m. This represents an average 18% and a maximum 77% over-estimation of the grain-size value in the flow resistance equation. Such potential errors, inherent with the conventional grid-by-number sampling technique, impact significantly on flood level estimation options.
Photon-photon collisions via relativisitic mirrors
Koga, James K. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan)
2012-07-11
Photon-photon scattering at low energies has been predicted theoretically for many years. However, due to the extremely small cross section there has been no experimental confirmation of this. Due to the rapid increase in laser irradiances and projected peak irradiances in planned facilities regimes could be reached where photon-photon scattering could be experimentally observed. We will first review basic aspects of photon-photon collisions concentrating on the calculation of the photon-photon scattering cross section. Then we will discuss the possibilities for observing these phenomena in ultra-high irradiance laser-plasma interactions involving relativistic mirrors.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM YUVAL BENJAMINI Department of Statistics University) and imaging (e.g. functional MRI) data from the visual cortex. These encoding models are trained to describe
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM PETER GUTTORP University of Washington and Norwegian Computing Center The Heat Is On! A Statistical Look at the State of the Climate MONDAY, May 6, 2013 at 4
Mocanu, L. M.; Crawford, T. M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crites, A. T.; Vieira, J. D.; Aird, K. A.; Aravena, M.; Austermann, J. E.; Everett, W. B.; Halverson, N. W.; Béthermin, M.; Chapman, S.; Cho, H.-M.; De Haan, T.; Dobbs, M. A.; George, E. M.; and others
2013-12-10
We present a point-source catalog from 771 deg{sup 2} of the South Pole Telescope Sunyaev-Zel'dovich survey at 95, 150, and 220 GHz. We detect 1545 sources above 4.5? significance in at least one band. Based on their relative brightness between survey bands, we classify the sources into two populations, one dominated by synchrotron emission from active galactic nuclei, and one dominated by thermal emission from dust-enshrouded star-forming galaxies. We find 1238 synchrotron and 307 dusty sources. We cross-match all sources against external catalogs and find 189 unidentified synchrotron sources and 189 unidentified dusty sources. The dusty sources without counterparts are good candidates for high-redshift, strongly lensed submillimeter galaxies. We derive number counts for each population from 1 Jy down to roughly 11, 4, and 11 mJy at 95, 150, and 220 GHz. We compare these counts with galaxy population models and find that none of the models we consider for either population provide a good fit to the measured counts in all three bands. The disparities imply that these measurements will be an important input to the next generation of millimeter-wave extragalactic source population models.
42 CFR 402.109 - Statistical sampling.
Code of Federal Regulations, 2010 CFR
2010-10-01
...introduce the results of a statistical sampling study to show the number and... The results of the statistical sampling study, if based upon an appropriate sampling and computed by valid statistical methods, constitute prima facie...
42 CFR 1003.133 - Statistical sampling.
Code of Federal Regulations, 2010 CFR
2010-10-01
...introduce the results of a statistical sampling study as evidence of the number...respondent. Such a statistical sampling study, if based upon an appropriate sampling and computed by valid statistical methods, shall constitute prima...
NASA Astrophysics Data System (ADS)
Telnov, Valery
2001-10-01
High energy photon colliders ( ??, ?e) based on backward Compton scattering of laser light is a very natural addition to e +e - linear colliders. In this report, we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case, the ?? luminosity in the high energy part of spectrum can reach about (1/3) Le +e -. Typical cross-sections of interesting processes in ?? collisions are higher than those in e +e - collisions by about one order of magnitude, so the number of events in ?? collisions will be more than that in e +e - collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is "an optical storage ring (optical trap)" with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems.
Statistics Canada = Statistique Canada
NSDL National Science Digital Library
Statistics Canada, a national statistical agency, offers this excellent collection on the economic and social conditions in Canada. Statistical information is divided into four broad topics: The Land, The People, The Economy, and the State. Within each are a number of sub-topics which offer lists of statistical tables. Newly released data, research papers, downloadable publications (Adobe Acrobat [.pdf] format only), and notices of seminars and conferences are featured in addition to The Daily, a collection of the latest news releases and publications from the agency. This site can be viewed in English or French. Note that there is a combination of free and fee based material available.
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…
Waveguide single-photon detectors for integrated quantum photonic circuits
J. P. Sprengers; A. Gaggero; D. Sahin; S. Jahanmiri Nejad; F. Mattioli; R. Leoni; J. Beetz; M. Lermer; M. Kamp; S. Höfling; R. Sanjines; A. Fiore
2011-08-25
The generation, manipulation and detection of quantum bits (qubits) encoded on single photons is at the heart of quantum communication and optical quantum information processing. The combination of single-photon sources, passive optical circuits and single-photon detectors enables quantum repeaters and qubit amplifiers, and also forms the basis of all-optical quantum gates and of linear-optics quantum computing. However, the monolithic integration of sources, waveguides and detectors on the same chip, as needed for scaling to meaningful number of qubits, is very challenging, and previous work on quantum photonic circuits has used external sources and detectors. Here we propose an approach to a fully-integrated quantum photonic circuit on a semiconductor chip, and demonstrate a key component of such circuit, a waveguide single-photon detector. Our detectors, based on superconducting nanowires on GaAs ridge waveguides, provide high efficiency (20%) at telecom wavelengths, high timing accuracy (60 ps), response time in the ns range, and are fully compatible with the integration of single-photon sources, passive networks and modulators.
Integrated spatial multiplexing of heralded single-photon sources
NASA Astrophysics Data System (ADS)
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.
2013-10-01
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.
Integrated spatial multiplexing of heralded single photon sources
Matthew J. Collins; Chunle Xiong; Isabella H. Rey; Trung D. Vo; Jiakun He; Shayan Shahnia; Christopher Reardon; M. J. Steel; Thomas F. Krauss; Alex S. Clark; Benjamin J. Eggleton
2013-05-31
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 correlated photon pair sources, demonstrating a 62.4% increase in the heralded single photon output without an increase in unwanted multi-pair 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.
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
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
Photon wave mechanics and position eigenvectors
Margaret Hawton
2007-05-22
One and two photon wave functions are derived by projecting the quantum state vector onto simultaneous eigenvectors of the number operator and a recently constructed photon position operator [Phys. Rev A 59, 954 (1999)] that couples spin and orbital angular momentum. While only the Landau-Peierls wave function defines a positive definite photon density, a similarity transformation to a biorthogonal field-potential pair of positive frequency solutions of Maxwell's equations preserves eigenvalues and expectation values. We show that this real space description of photons is compatible with all of the usual rules of quantum mechanics and provides a framework for understanding the relationships amongst different forms of the photon wave function in the literature. It also gives a quantum picture of the optical angular momentum of beams that applies to both one photon and coherent states. According to the rules of qunatum mechanics, this wave function gives the probability to count a photon at any position in space.
Image Science with Photon-Processing Detectors
Caucci, Luca; Jha, Abhinav K.; Furenlid, Lars R.; Clarkson, Eric W.; Kupinski, Matthew A.; Barrett, Harrison H.
2015-01-01
We introduce and discuss photon-processing detectors and we compare them with photon-counting detectors. By estimating a relatively small number of attributes for each collected photon, photon-processing detectors may help understand and solve a fundamental theoretical problem of any imaging system based on photon-counting detectors, namely null functions. We argue that photon-processing detectors can improve task performance by estimating position, energy, and time of arrival for each collected photon. We consider a continuous-to-continuous linear operator to relate the object being imaged to the collected data, and discuss how this operator can be analyzed to derive properties of the imaging system. Finally, we derive an expression for the characteristic functional of an imaging system that produces list-mode data.
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.
Hybrid approach to mean-variance and photon transfer measurement
NASA Astrophysics Data System (ADS)
Jacquot, Blake C.; Bolla, Brett M.; Maguire, Sean
2015-05-01
This paper presents a hybrid technique for measuring conversion gain that blends spatial and temporal information, allowing users to calculate an accurate conversion gain with little knowledge of sensor defects. It blends a single pixel method with multiple pixel methods. We present measured data from a visible CMOS image sensor using two multiple pixel methods and the hybrid method. Additionally, we provide arguments for validity of the hybrid method. To our knowledge, this is the first report of this technique. Conversion gain (e-/DN) directly relates measured digital numbers (DN) to input-referred electrons (e-) for an image sensor. Conversion gain can be directly measured by considering the sensor under varying illumination states in coordination with Poisson statistics. Typically, there are two approaches: measure a single pixel over time or measure a group of pixels at one point in time after correcting for gain non-uniformity. The plotted statistics from these measurements are called either mean-variance or photon-transfer curves. The measurement of a single pixel is relatively straightforward and requires collection of many consecutive frames to get meaningful statistics not dominated by thermal noise. The data volume for an accurate single-pixel measurement can become unwieldy in terms of number of frames required. This is especially true for large format image sensors. In contrast, the measurement of a group of pixels requires fewer consecutive frames, but needs non-uniformity adjustments to correctly calculate statistics.
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…
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)
Schmidt, Heinz-Jürgen; Homann, Felix
2000-05-01
We discuss numerical solutions of Einstein's field equation describing static, spherically symmetric conglomerations of a photon gas. These equations imply a back reaction of the metric on the energy density of the photon gas according to Tolman's equation. The 3-fold of solutions corresponds to a class of physically different solutions which is parameterized by only two quantities, i.e. mass and surface temperature. The energy density is typically concentrated on a shell because the center contains a repelling singularity, which can, however, not be reached by timelike geodesics and only by radial null geodesics. The physical relevance of these solutions is completely open, although their existence may raise some doubts w.r.t. the stability of black holes.
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.
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM SRIRAM SANKARARAMAN Department of Genetics Harvard Medical School Statistical Models for Analyzing Ancient Human Admixture WEDNESDAY, January 21, 2015, at 4 become available, as well as appropriate statistical models. In the first part of my talk, I will focus
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM PIOTR ZWIERNIK Department of Mathematics University of Genoa Understanding Statistical Models Through Their Geometry MONDAY, January 26, 2015, at 4:00 PM and Gaussian statistical models have a rich geometric structure and can be often viewed as algebraic sets
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM ROBERT NOWAK Department of Electrical and Computer-dimensional statistical models to capture the complexity of such problems. Most of the work in this direction has focused of statistical inference. These procedures automatically adapt the measurements in order to focus and optimize
Department of Statistics STATISTICS COLLOQUIUM
Department of Statistics STATISTICS COLLOQUIUM INGRAM OLKIN Department of Statistics Stanford the concept of majorization is called mixing and in physics it is referred to as chaotic (one vector is more probability, statistics, combinatorics and graphs, numerical analysis and matrix theory. Special emphasis
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.
Photon transitions in Upsilon(2S) and Upsilon(3S) decays
Besson, David Zeke
2005-01-01
We have studied the inclusive photon spectra in Y(2S) and Y(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon ...
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.
Light scattering from ultracold atoms in optical lattices as an optical probe of quantum statistics
Mekhov, Igor B.; Maschler, Christoph; Ritsch, Helmut
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.
Teleportation-based number-state manipulation with number-sum measurement
Kitagawa, Akira; Yamamoto, Katsuji
2003-10-01
We examine various manipulations of photon number states which can be implemented by teleportation technique with number-sum measurement. The preparations of the Einstein-Podolsky-Rosen resources as well as the number-sum measurement resulting in projection to certain Bell state may be done conditionally with linear optical elements, i.e., beam splitters, phase shifters, and zero-one-photon detectors. Squeezed vacuum states are used as primary entanglement resource, while single-photon sources are not required.
Exciton-photon correlations in bosonic condensates of exciton-polaritons
Kavokin, Alexey V.; Sheremet, Alexandra S.; Shelykh, Ivan A.; Lagoudakis, Pavlos G.; Rubo, Yuri G.
2015-01-01
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a statistical model describing stochastic exciton-photon transitions within a condensate of exciton polaritons. We show that the exciton-photon correlator depends on the rate of incoherent exciton-photon transformations in the condensate. We discuss implications of this effect for the quantum statistics of photons emitted by polariton lasers. PMID:26153979
Exciton-photon correlations in bosonic condensates of exciton-polaritons.
Kavokin, Alexey V; Sheremet, Alexandra S; Shelykh, Ivan A; Lagoudakis, Pavlos G; Rubo, Yuri G
2015-01-01
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a statistical model describing stochastic exciton-photon transitions within a condensate of exciton polaritons. We show that the exciton-photon correlator depends on the rate of incoherent exciton-photon transformations in the condensate. We discuss implications of this effect for the quantum statistics of photons emitted by polariton lasers. PMID:26153979
Quantum imaging with undetected photons.
Lemos, Gabriela Barreto; Borish, Victoria; Cole, Garrett D; Ramelow, Sven; Lapkiewicz, Radek; Zeilinger, Anton
2014-08-28
Information is central to quantum mechanics. In particular, quantum interference occurs only if there exists no information to distinguish between the superposed states. The mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference. Here we introduce and experimentally demonstrate a quantum imaging concept based on induced coherence without induced emission. Our experiment uses two separate down-conversion nonlinear crystals (numbered NL1 and NL2), each illuminated by the same pump laser, creating one pair of photons (denoted idler and signal). If the photon pair is created in NL1, one photon (the idler) passes through the object to be imaged and is overlapped with the idler amplitude created in NL2, its source thus being undefined. Interference of the signal amplitudes coming from the two crystals then reveals the image of the object. The photons that pass through the imaged object (idler photons from NL1) are never detected, while we obtain images exclusively with the signal photons (from NL1 and NL2), which do not interact with the object. Our experiment is fundamentally different from previous quantum imaging techniques, such as interaction-free imaging or ghost imaging, because now the photons used to illuminate the object do not have to be detected at all and no coincidence detection is necessary. This enables the probe wavelength to be chosen in a range for which suitable detectors are not available. To illustrate this, we show images of objects that are either opaque or invisible to the detected photons. Our experiment is a prototype in quantum information--knowledge can be extracted by, and about, a photon that is never detected. PMID:25164751
Cosmic statistics of statistics
NASA Astrophysics Data System (ADS)
Szapudi, István; Colombi, Stéphane; Bernardeau, Francis
1999-12-01
The errors on statistics measured in finite galaxy catalogues are exhaustively investigated. The theory of errors on factorial moments by Szapudi & Colombi is applied to cumulants via a series expansion method. All results are subsequently extended to the weakly non-linear regime. Together with previous investigations this yields an analytic theory of the errors for moments and connected moments of counts in cells from highly non-linear to weakly non-linear scales. For non-linear functions of unbiased estimators, such as the cumulants, the phenomenon of cosmic bias is identified and computed. Since it is subdued by the cosmic errors in the range of applicability of the theory, correction for it is inconsequential. In addition, the method of Colombi, Szapudi & Szalay concerning sampling effects is generalized, adapting the theory for inhomogeneous galaxy catalogues. While previous work focused on the variance only, the present article calculates the cross-correlations between moments and connected moments as well for a statistically complete description. The final analytic formulae representing the full theory are explicit but somewhat complicated. Therefore we have made available a fortran program capable of calculating the described quantities numerically (for further details e-mail SC at colombi@iap.fr). An important special case is the evaluation of the errors on the two-point correlation function, for which this should be more accurate than any method put forward previously. This tool will be immensely useful in the future for assessing the precision of measurements from existing catalogues, as well as aiding the design of new galaxy surveys. To illustrate the applicability of the results and to explore the numerical aspects of the theory qualitatively and quantitatively, the errors and cross-correlations are predicted under a wide range of assumptions for the future Sloan Digital Sky Survey. The principal results concerning the cumulants ?, Q3 and Q4 is that the relative error is expected to be smaller than 3, 5 and 15per cent, respectively, in the scale range of 1-10h-1Mpc the cosmic bias will be negligible.
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.
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.
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
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Elementary Business Statistics Unique Number 04595, 04600
Ghosh, Joydeep
_alaubaidy@utexas.edu Shannon Provost Email: smprovost@gmail.com COURSE MATERIALS MyStatLab at https-book that is included with MyStatLab or purchase a text and MyStatLab access code. You can order directly from will take an active role in your learning. You will have responsibility for learning new content online
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
Entangled-photon compressive ghost imaging
Zerom, Petros; Chan, Kam Wai Clifford; Howell, John C.; Boyd, Robert W.
2011-12-15
We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.
Direct generation of photon triplets using cascaded photon-pair sources.
Hübel, Hannes; Hamel, Deny R; Fedrizzi, Alessandro; Ramelow, Sven; Resch, Kevin J; Jennewein, Thomas
2010-07-29
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 spontaneous parametric down-conversion of laser light into photon pairs. Conservation of energy and momentum in this process, known as phase-matching, gives rise to strong correlations that are used to produce two-photon entanglement in various degrees of freedom. It has been a longstanding goal in quantum optics to realize a source that can produce analogous correlations in photon triplets, but of the many approaches considered, none has been technically feasible. Here we report the observation of photon triplets generated by cascaded down-conversion. 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. Our photon-triplet source will allow experimental interrogation of novel quantum correlations, the 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, suitable 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. PMID:20671705