We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems.The emission intensity I and Mandel's Q parameter show stochastic resonance with respect to the pure dephas...We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems.The emission intensity I and Mandel's Q parameter show stochastic resonance with respect to the pure dephasing constantγp.The amplitude fluctuation of the field causes these systems to lose their coherence.On the other hand,the amplitude fluctuation provides a new interference method for these systems.The quantum beats are shown in the orthogonal system.展开更多
Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of singl...Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of single-barrier structure is performed to obtain time series for two types of widely applicable exclusion models, counter-flows model, and tunnel model. With high-order spectrum analysis of Matlab, the validation of Monte Carlo methods is shown through the extracted first four cumulants from the time series, which are in agreement with those from cumulant generating function. After the comparison between the counter-flows model and the tunnel model in a single barrier structure, it is found that the essential difference between them consists in the strictly holding of Pauli principle in the former and in the statistical consideration of Pauli principle in the latter.展开更多
The full counting statistics of electron transport through two parallel quantum dots with antiparallel magnetic fluxes is investigated as a probe to detect the topological quantum-phase coherence (TQPC), which resul...The full counting statistics of electron transport through two parallel quantum dots with antiparallel magnetic fluxes is investigated as a probe to detect the topological quantum-phase coherence (TQPC), which results in the characteristic oscillation of the zero-frequency cumulants including the shot noise and skewness. We show explicitly the phase transition of cumulant spectrum-patterns induced by the topology change of electron path-loops while the pattern period, which depends only on the topology (or Chern number), is robust against the variation of Coulomb interaction and interdot coupling strengths. Most importantly we report for the first time on a new type of TQPC, which is generated by the two- particle interaction and does not exist in the single-particle wave function interference. Moreover, the accurately quantized peaks of Fano-factor spectrum, which characterize the super- and sub-Poissonian shot noises, are of fundamental importance in technical applications similar to the superconducting quantum interference device.展开更多
Loop detectors are wide-spread and relatively cheap detecting devices. With today's traffic communication revolution, high resolution detector data is available on a central traffic management level. High resolution ...Loop detectors are wide-spread and relatively cheap detecting devices. With today's traffic communication revolution, high resolution detector data is available on a central traffic management level. High resolution detector data consist of detector slopes, also called pulse data. There is an initial and continuous need for checking the detectors for correct data as all kinds of disturbances may add erroneous information to the data. This paper proposes pulse data checking and interval data checking with optional data replacement in order to guarantee a continuous data flow even if detectors do not deliver the expected data quality: Raw detector data checking analyses rising and falling slopes of detector signals; Cumulative data checking compares interval values to reference curves. Cumulative data checking needs less computational effort, but needs more parameterization effort than raw detector data checking. Both checking principles are applied to different systems in Switzerland since about five years.展开更多
In order to explore how to extract more transport information from current fluctuation, a theoretical extraction scheme is presented in a single barrier structure based on exclusion models, which include counter-flows...In order to explore how to extract more transport information from current fluctuation, a theoretical extraction scheme is presented in a single barrier structure based on exclusion models, which include counter-flows model and tunnel model. The first four cumulants of these two exclusion models are computed in a single barrier structure, and their characteristics are obtained. A scheme with the help of the first three cumulants is devised to check a transport process to follow the counter-flows model, the tunnel model or neither of them. Time series generated by Monte Carlo techniques is adopted to validate the abstraction procedure, and the result is reasonable.展开更多
The coherent potential approximation(CPA)within full counting statistics(FCS)formalism is shown to be a suitable method to investigate average electric conductance,shot noise as well as higher order cumulants in disor...The coherent potential approximation(CPA)within full counting statistics(FCS)formalism is shown to be a suitable method to investigate average electric conductance,shot noise as well as higher order cumulants in disordered systems.We develop a similar FCS-CPA formalism for phonon transport through disordered systems.As a byproduct,we derive relations among coefficients of different phonon current cumulants.We apply the FCS-CPA method to investigate phonon transport properties of graphene systems in the presence of disorders.For binary disorders as well as Anderson disorders,we calculate up to the 8-th phonon transmission moments and demonstrate that the numerical results of the FCS-CPA method agree very well with that of the brute force method.The benchmark shows that the FCS-CPA method achieves 20 times more speedup ratio.Collective features of phonon current cumulants are also revealed.展开更多
基金supported by the National Natural Science Foundation of China(Grand Nos.91021009,21073110,and 11374191)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2013AQ020)+1 种基金the Postdoctoral Science Foundation of China(Grant No.2013M531584)the Doctoral Program of Higher Education of China(Grant Nos.20130131110005 and 20130131120006)
文摘We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems.The emission intensity I and Mandel's Q parameter show stochastic resonance with respect to the pure dephasing constantγp.The amplitude fluctuation of the field causes these systems to lose their coherence.On the other hand,the amplitude fluctuation provides a new interference method for these systems.The quantum beats are shown in the orthogonal system.
基金Project supported by the National Natural Science Foundation of China(Grant No.60676053)Applied Material in Xi'an Innovation Funds(Grant No.XA-AM-200603)
文摘Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of single-barrier structure is performed to obtain time series for two types of widely applicable exclusion models, counter-flows model, and tunnel model. With high-order spectrum analysis of Matlab, the validation of Monte Carlo methods is shown through the extracted first four cumulants from the time series, which are in agreement with those from cumulant generating function. After the comparison between the counter-flows model and the tunnel model in a single barrier structure, it is found that the essential difference between them consists in the strictly holding of Pauli principle in the former and in the statistical consideration of Pauli principle in the latter.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11075099.11204203,and 11275118)
文摘The full counting statistics of electron transport through two parallel quantum dots with antiparallel magnetic fluxes is investigated as a probe to detect the topological quantum-phase coherence (TQPC), which results in the characteristic oscillation of the zero-frequency cumulants including the shot noise and skewness. We show explicitly the phase transition of cumulant spectrum-patterns induced by the topology change of electron path-loops while the pattern period, which depends only on the topology (or Chern number), is robust against the variation of Coulomb interaction and interdot coupling strengths. Most importantly we report for the first time on a new type of TQPC, which is generated by the two- particle interaction and does not exist in the single-particle wave function interference. Moreover, the accurately quantized peaks of Fano-factor spectrum, which characterize the super- and sub-Poissonian shot noises, are of fundamental importance in technical applications similar to the superconducting quantum interference device.
文摘Loop detectors are wide-spread and relatively cheap detecting devices. With today's traffic communication revolution, high resolution detector data is available on a central traffic management level. High resolution detector data consist of detector slopes, also called pulse data. There is an initial and continuous need for checking the detectors for correct data as all kinds of disturbances may add erroneous information to the data. This paper proposes pulse data checking and interval data checking with optional data replacement in order to guarantee a continuous data flow even if detectors do not deliver the expected data quality: Raw detector data checking analyses rising and falling slopes of detector signals; Cumulative data checking compares interval values to reference curves. Cumulative data checking needs less computational effort, but needs more parameterization effort than raw detector data checking. Both checking principles are applied to different systems in Switzerland since about five years.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60676053)Applied Material in Xi’an Innovation Funds,China (Grant No. XA-AM-200603)
文摘In order to explore how to extract more transport information from current fluctuation, a theoretical extraction scheme is presented in a single barrier structure based on exclusion models, which include counter-flows model and tunnel model. The first four cumulants of these two exclusion models are computed in a single barrier structure, and their characteristics are obtained. A scheme with the help of the first three cumulants is devised to check a transport process to follow the counter-flows model, the tunnel model or neither of them. Time series generated by Monte Carlo techniques is adopted to validate the abstraction procedure, and the result is reasonable.
基金the National Natural Science Foundation of China(Grant No.12034014)the Natural Science Foundation of Guangdong Province(Grant No.2020A1515011418).
文摘The coherent potential approximation(CPA)within full counting statistics(FCS)formalism is shown to be a suitable method to investigate average electric conductance,shot noise as well as higher order cumulants in disordered systems.We develop a similar FCS-CPA formalism for phonon transport through disordered systems.As a byproduct,we derive relations among coefficients of different phonon current cumulants.We apply the FCS-CPA method to investigate phonon transport properties of graphene systems in the presence of disorders.For binary disorders as well as Anderson disorders,we calculate up to the 8-th phonon transmission moments and demonstrate that the numerical results of the FCS-CPA method agree very well with that of the brute force method.The benchmark shows that the FCS-CPA method achieves 20 times more speedup ratio.Collective features of phonon current cumulants are also revealed.