We propose a scheme for probabilistic teleportation of an unknown two-particle state with a four-particle pure entangled state and positive operator valued measure （POVM）. In this scheme the teleportation of an unkn...We propose a scheme for probabilistic teleportation of an unknown two-particle state with a four-particle pure entangled state and positive operator valued measure （POVM）. In this scheme the teleportation of an unknown two-particle state can be realized with certain probability by performing two Bell state measurements, a proper POVM and a unitary transformation.展开更多
We propose a simultaneous quantum secure direct communication scheme between one party and other three parties via four-particle GHZ states and swapping quantum entanglement. In the scheme, three spatially separated s...We propose a simultaneous quantum secure direct communication scheme between one party and other three parties via four-particle GHZ states and swapping quantum entanglement. In the scheme, three spatially separated senders, Alice, Bob and Charlie, transmit their secret messages to a remote receiver Diana by performing a series of local operations on their respective particles according to the quadripartite stipulation. From Alice, Bob, Charlie and Diana＇s Bell measurement results, Diana can infer the secret messages. Ira perfect quantum channel is used, the secret messages are faithfully transmitted from Alice, Bob and Charlie to Diana via initially shared pairs of four-particle GHZ states without revealing any information to a potential eavesdropper. As there is no transmission of the qubits carrying the secret message in the public channel, it is completely secure for the direct secret communication. This scheme can be considered as a network of communication parties where each party wants to communicate secretly with a central party or server.展开更多
A two-dimensional single-mode laser model with cross-correlations between the real and imaginary parts of the quantum noise as well as the pump noise is investigated.The general closed form of the laser intensity Lang...A two-dimensional single-mode laser model with cross-correlations between the real and imaginary parts of the quantum noise as well as the pump noise is investigated.The general closed form of the laser intensity Langevin equation(GILE)is obtained under a stable locked phase resulting from the cross-correlationλ_(q) between the real and imaginary parts of the quantum noise.Because of the presence of a new term containingλ_(q),we can unify the two opposite intensity Langevin equations which correspond to the two special cases for|λ_(q)|→0 and|λ_(q)|→1 in the GILE.It is expected that the transient and stationary properties of the laser model can be changed qualitatively whenλ_(q) varies.展开更多
The energy and effective mass of a polaron in a parabolic quantum well are studied theoretically by using LLP-like transformations and a variational approach. Numerical results are presented for the polaron energy and...The energy and effective mass of a polaron in a parabolic quantum well are studied theoretically by using LLP-like transformations and a variational approach. Numerical results are presented for the polaron energy and effective mass in the GaAs/Al0.3Ga0.7As parabolic quantum well. The results show that the energy and the effective mass of the polaron both have their maxima in the finite parabolic quantum well but decrease monotonously in the infinite parabolic quantum well with the increasing well width. It is verified that the bulk longitudinal optical phonon mode approximation is an adequate formulation for the electron-phonon coupling in parabolic quantum well structures.展开更多
By using linear approximation we derive expressions for the correlation function,power spectrum and correlation time of the output light intensity in a single-mode laser driven by additive white noise and multiplicati...By using linear approximation we derive expressions for the correlation function,power spectrum and correlation time of the output light intensity in a single-mode laser driven by additive white noise and multiplicative colored noise with an exponential correlation form.The effects of correlation strength and correlation time of the noises on the above quantities are discussed and compared with the case of a delta function correlation form for the noises.展开更多
A new concise approach is presented for analytic study of the properties of the Holstein model. New analytic results for the polaronic band structure and phonon distribution, of the Holstein molecular crystal model, a...A new concise approach is presented for analytic study of the properties of the Holstein model. New analytic results for the polaronic band structure and phonon distribution, of the Holstein molecular crystal model, are given in one dimension. And all analytic results given are in accordance with the known numerical research results.展开更多
This paper uses the relation of the cosmic scale factor and scalar field to solve Wheeler-De Witt equation,gives the tunnel effect of the cosmic scale factor a and quantum potential well of scalar field, and makes it ...This paper uses the relation of the cosmic scale factor and scalar field to solve Wheeler-De Witt equation,gives the tunnel effect of the cosmic scale factor a and quantum potential well of scalar field, and makes it fit with the physics of cosmic quantum birth. By solving Wheeler-De Witt equation we achieve a general probability distribution of the cosmic birth, and give the analysis of cosmic quantum birth.展开更多
Using the scale evolution of nuclear parton distributions,the contribution of color-octet heavy quarkonium production mechanism to the P + Fe → J/ψ + γ + X process in calculated and discussed.Comparing our theoreti...Using the scale evolution of nuclear parton distributions,the contribution of color-octet heavy quarkonium production mechanism to the P + Fe → J/ψ + γ + X process in calculated and discussed.Comparing our theoretical results with the future experimental data,the color-octet heavy quarkonium production mechanism can be examined.展开更多
In the study,a bistable system is driven by additive colored noise and multiplicative colored noise,whose correlation is of an exponential farm.When the noises are correlated,it is found that the system undergoes a re...In the study,a bistable system is driven by additive colored noise and multiplicative colored noise,whose correlation is of an exponential farm.When the noises are correlated,it is found that the system undergoes a reentrant transition as the correlation strength between noises or multiplicative noise intensity changes,while there is no such phenomenon as the additive noise intensity or the time of correlation changes.No reentrant transition exists when the noises are uncorrelated.展开更多
The dynamic nature of phase synchronization between chaotic outputs and injected periodic signals is investigated.We find that the collapse of stroboscopic section from global distribution to local one and the loss of...The dynamic nature of phase synchronization between chaotic outputs and injected periodic signals is investigated.We find that the collapse of stroboscopic section from global distribution to local one and the loss of homogeneity of stroboscopic sections in chaotic attractors for different phases are the key features of this kind of phase synchronization,meanwhile the overall structure of chaotic attractor is not affected apparently by the phase synchronization.展开更多
The equations of motion of the soliton transported bio-energy in the protein,were heretofore already obtained by a combination of quantum-mechanical and classical methods,but here have been derived based completely on...The equations of motion of the soliton transported bio-energy in the protein,were heretofore already obtained by a combination of quantum-mechanical and classical methods,but here have been derived based completely on quantum mechanics.And we point out the shortcoming of no self-consistency of the Davydov theory.Some interesting results have also been got.展开更多
We consider the lepton-flavor violating (LFV) processes li → ljγ in the framework of topcolor-assistedtechnicolor (TC2) models. We find that the new gauge boson Z' predicted by TC2 models can give significantlyc...We consider the lepton-flavor violating (LFV) processes li → ljγ in the framework of topcolor-assistedtechnicolor (TC2) models. We find that the new gauge boson Z' predicted by TC2 models can give significantlycontributions to these processes via the flavor-changing couplings Z'lilj. The present experimental bound on the LFVprocess μ→ eγ gives severe constraints on the TC2 models. Using other experimental constraints on the Z' mass Mz,we obtain constraints on the lepton mixing factors KTμ and KTe. The future LFV experiments will probe into TC2models.展开更多
We study the escape problem of a bistable sawtooth system driven by correlated multiplicative and additive white noises.Exact analytic representation of the relative escape rate is obtained.Some novel phenomena are fo...We study the escape problem of a bistable sawtooth system driven by correlated multiplicative and additive white noises.Exact analytic representation of the relative escape rate is obtained.Some novel phenomena are found from the calculation result;“suppression platform”appears in the relative escape rate when the noise correlation coefficientλis positive.Moreover,for small positive values ofλ,the relative escape rate exhibits“suppression platform”and then“resonant activation”with the increasing noise strength ratio R.展开更多
By means of a relativistic effective potential, we analytically research competition between the quark- antiquark condensates （qq） and the diquark condensates （qq） in vacuum in ground state of a two-flavor Nambu J...By means of a relativistic effective potential, we analytically research competition between the quark- antiquark condensates （qq） and the diquark condensates （qq） in vacuum in ground state of a two-flavor Nambu Jona Lasinio （NJL） model and obtain the Gs-Hs phase diagram, where Gs and Hs are the respective four-fermion coupling constants in scalar quark-antiquark channel and scalar color anti-triplet diquark channel. The results show that, in the chiral limit, there is only the pure （qq） phase when Gs/Hs 〉 2/3, and as Gs/Hs decreases to 2/3 〉 Gs/Hs ≥ 0 one will first have a coexistence phase of the condensates （qq） and （qq） and then a pure （qq） phase. In non-zero bare quark mass case, the critical value of Gs/Hs at which the pure （qq） phase will transfer to the coexistence phase of the condensates （qq） and （qq） will be less than 2/3. Our theoretical results, combined with present phenomenological fact that there is no diquark condensates in the vacuum of QCD, will also impose a real restriction to any given two-flavor NJL model which is intended to simulate QCD, i.e. in such model the resulting sma/lest ratio Gs/Hs after the Fierz transformations in the Hartree approximation must be larger than 2/3. A few phenomenological QCD-like NJL models are checked and analyzed.展开更多
Using the linear approximation method, we have studied how the correlation function C（t） of the laser intensity changes with time in the loss-noise model of the single-mode laser driven by the colored pump noise wit...Using the linear approximation method, we have studied how the correlation function C（t） of the laser intensity changes with time in the loss-noise model of the single-mode laser driven by the colored pump noise with signal modulation and the quantum noise with cross-correlation between the real and imaginary parts. We have found that when the pump noise self-correlation time T changes, （i） in the case of r 〈〈 1, the C（t） vs. t curve experiences a changing process from the monotonous descending to monotonous rise, and finally to the appearance of a maximum; （ii） in the case of r 〉〉 1, the curve only exhibits periodically surging with descending envelope. When r 〈〈 i and T does not change, with the increase of the pump noise intensity P, the curve experiences a repeated changing process, that is, from the monotonous descending to the appearance of a maximum, then to monotonous rise, and finally to the appearance of a maximum again. With the increase of the quantum noise intensity O,, the curve experiences a changing process from the monotonous rise to the appearance of a maximum, and finally to the monotonous descending. The increase of the quantum noise with cross-correlation between the real and imaginary parts will lead to the fall of the whole curve, but not affect the form of the time evolution of C（t）.展开更多
Exact formulas for the power spectrum and signal-to-noise ratio (SNR) with periodic additive signal arecalculated in the linear system.Then the phenomenon of resonance is studied in detail.We show that resonancepeak a...Exact formulas for the power spectrum and signal-to-noise ratio (SNR) with periodic additive signal arecalculated in the linear system.Then the phenomenon of resonance is studied in detail.We show that resonancepeak and suppressed valley exist in the curves of the SNR versus the coefficient of self-saturation, the net gain and thecross-coupling coefficient of the laser system.展开更多
By using a simple transformation approach,we solve the higher-order nonlinear Schrödinger equation under another condition.The obtained exact soliton solutions have the following prominent features:The bright sol...By using a simple transformation approach,we solve the higher-order nonlinear Schrödinger equation under another condition.The obtained exact soliton solutions have the following prominent features:The bright soliton can propagate in both the normal and anormal regions;the soliton travelling speed is proportional to its amplitude square;the phase of the soliton is independent of its amplitude or width;and the component solitons of the bound soliton have the same phase.展开更多
基金Supported by the Hebei Natural Science Foundation of China under Grant Nos A2004000141 and A2005000140, and the Natural Science Foundation of Hebei Normal University.
文摘We propose a scheme for probabilistic teleportation of an unknown two-particle state with a four-particle pure entangled state and positive operator valued measure （POVM）. In this scheme the teleportation of an unknown two-particle state can be realized with certain probability by performing two Bell state measurements, a proper POVM and a unitary transformation.
基金Supported by the Natural Science Foundation of Hebei Province under Grant Nos A2004000141 and A2005000140, and the Natural Science Foundation of Hebei Normal University.
文摘We propose a simultaneous quantum secure direct communication scheme between one party and other three parties via four-particle GHZ states and swapping quantum entanglement. In the scheme, three spatially separated senders, Alice, Bob and Charlie, transmit their secret messages to a remote receiver Diana by performing a series of local operations on their respective particles according to the quadripartite stipulation. From Alice, Bob, Charlie and Diana＇s Bell measurement results, Diana can infer the secret messages. Ira perfect quantum channel is used, the secret messages are faithfully transmitted from Alice, Bob and Charlie to Diana via initially shared pairs of four-particle GHZ states without revealing any information to a potential eavesdropper. As there is no transmission of the qubits carrying the secret message in the public channel, it is completely secure for the direct secret communication. This scheme can be considered as a network of communication parties where each party wants to communicate secretly with a central party or server.
基金Supported by the National Natural Science Foundation of China under Grant No.19975020.
文摘A two-dimensional single-mode laser model with cross-correlations between the real and imaginary parts of the quantum noise as well as the pump noise is investigated.The general closed form of the laser intensity Langevin equation(GILE)is obtained under a stable locked phase resulting from the cross-correlationλ_(q) between the real and imaginary parts of the quantum noise.Because of the presence of a new term containingλ_(q),we can unify the two opposite intensity Langevin equations which correspond to the two special cases for|λ_(q)|→0 and|λ_(q)|→1 in the GILE.It is expected that the transient and stationary properties of the laser model can be changed qualitatively whenλ_(q) varies.
基金Supported by the National Natural Science Foundation of China under Grant No 10164003, and the Natural Science Foundation of Inner Mongol of China under Grant No 200408020101.
文摘The energy and effective mass of a polaron in a parabolic quantum well are studied theoretically by using LLP-like transformations and a variational approach. Numerical results are presented for the polaron energy and effective mass in the GaAs/Al0.3Ga0.7As parabolic quantum well. The results show that the energy and the effective mass of the polaron both have their maxima in the finite parabolic quantum well but decrease monotonously in the infinite parabolic quantum well with the increasing well width. It is verified that the bulk longitudinal optical phonon mode approximation is an adequate formulation for the electron-phonon coupling in parabolic quantum well structures.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19475013,19675014。
文摘By using linear approximation we derive expressions for the correlation function,power spectrum and correlation time of the output light intensity in a single-mode laser driven by additive white noise and multiplicative colored noise with an exponential correlation form.The effects of correlation strength and correlation time of the noises on the above quantities are discussed and compared with the case of a delta function correlation form for the noises.
基金Supported by the Special Foundation of President of Chinese Academy of Sciences.
文摘A new concise approach is presented for analytic study of the properties of the Holstein model. New analytic results for the polaronic band structure and phonon distribution, of the Holstein molecular crystal model, are given in one dimension. And all analytic results given are in accordance with the known numerical research results.
基金Acknowledgments 0ne of the authors （Y.C. Huang） is grateful to Profs R.G. Cai and D.H. Zhang for useful discussions.
文摘This paper uses the relation of the cosmic scale factor and scalar field to solve Wheeler-De Witt equation,gives the tunnel effect of the cosmic scale factor a and quantum potential well of scalar field, and makes it fit with the physics of cosmic quantum birth. By solving Wheeler-De Witt equation we achieve a general probability distribution of the cosmic birth, and give the analysis of cosmic quantum birth.
文摘Using the scale evolution of nuclear parton distributions,the contribution of color-octet heavy quarkonium production mechanism to the P + Fe → J/ψ + γ + X process in calculated and discussed.Comparing our theoretical results with the future experimental data,the color-octet heavy quarkonium production mechanism can be examined.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19475013,19675014.
文摘In the study,a bistable system is driven by additive colored noise and multiplicative colored noise,whose correlation is of an exponential farm.When the noises are correlated,it is found that the system undergoes a reentrant transition as the correlation strength between noises or multiplicative noise intensity changes,while there is no such phenomenon as the additive noise intensity or the time of correlation changes.No reentrant transition exists when the noises are uncorrelated.
基金Supported in part by the National Natural Science Foundation of China under Grant No.19835020.
文摘The dynamic nature of phase synchronization between chaotic outputs and injected periodic signals is investigated.We find that the collapse of stroboscopic section from global distribution to local one and the loss of homogeneity of stroboscopic sections in chaotic attractors for different phases are the key features of this kind of phase synchronization,meanwhile the overall structure of chaotic attractor is not affected apparently by the phase synchronization.
文摘The equations of motion of the soliton transported bio-energy in the protein,were heretofore already obtained by a combination of quantum-mechanical and classical methods,but here have been derived based completely on quantum mechanics.And we point out the shortcoming of no self-consistency of the Davydov theory.Some interesting results have also been got.
文摘We consider the lepton-flavor violating (LFV) processes li → ljγ in the framework of topcolor-assistedtechnicolor (TC2) models. We find that the new gauge boson Z' predicted by TC2 models can give significantlycontributions to these processes via the flavor-changing couplings Z'lilj. The present experimental bound on the LFVprocess μ→ eγ gives severe constraints on the TC2 models. Using other experimental constraints on the Z' mass Mz,we obtain constraints on the lepton mixing factors KTμ and KTe. The future LFV experiments will probe into TC2models.
基金Supported by the National Natural Science Foundation of China under Grant No.19975020。
文摘We study the escape problem of a bistable sawtooth system driven by correlated multiplicative and additive white noises.Exact analytic representation of the relative escape rate is obtained.Some novel phenomena are found from the calculation result;“suppression platform”appears in the relative escape rate when the noise correlation coefficientλis positive.Moreover,for small positive values ofλ,the relative escape rate exhibits“suppression platform”and then“resonant activation”with the increasing noise strength ratio R.
基金The project supported by National Natural Science Foundation of China under Grant No, 10475113
文摘By means of a relativistic effective potential, we analytically research competition between the quark- antiquark condensates （qq） and the diquark condensates （qq） in vacuum in ground state of a two-flavor Nambu Jona Lasinio （NJL） model and obtain the Gs-Hs phase diagram, where Gs and Hs are the respective four-fermion coupling constants in scalar quark-antiquark channel and scalar color anti-triplet diquark channel. The results show that, in the chiral limit, there is only the pure （qq） phase when Gs/Hs 〉 2/3, and as Gs/Hs decreases to 2/3 〉 Gs/Hs ≥ 0 one will first have a coexistence phase of the condensates （qq） and （qq） and then a pure （qq） phase. In non-zero bare quark mass case, the critical value of Gs/Hs at which the pure （qq） phase will transfer to the coexistence phase of the condensates （qq） and （qq） will be less than 2/3. Our theoretical results, combined with present phenomenological fact that there is no diquark condensates in the vacuum of QCD, will also impose a real restriction to any given two-flavor NJL model which is intended to simulate QCD, i.e. in such model the resulting sma/lest ratio Gs/Hs after the Fierz transformations in the Hartree approximation must be larger than 2/3. A few phenomenological QCD-like NJL models are checked and analyzed.
文摘Using the linear approximation method, we have studied how the correlation function C（t） of the laser intensity changes with time in the loss-noise model of the single-mode laser driven by the colored pump noise with signal modulation and the quantum noise with cross-correlation between the real and imaginary parts. We have found that when the pump noise self-correlation time T changes, （i） in the case of r 〈〈 1, the C（t） vs. t curve experiences a changing process from the monotonous descending to monotonous rise, and finally to the appearance of a maximum; （ii） in the case of r 〉〉 1, the curve only exhibits periodically surging with descending envelope. When r 〈〈 i and T does not change, with the increase of the pump noise intensity P, the curve experiences a repeated changing process, that is, from the monotonous descending to the appearance of a maximum, then to monotonous rise, and finally to the appearance of a maximum again. With the increase of the quantum noise intensity O,, the curve experiences a changing process from the monotonous rise to the appearance of a maximum, and finally to the monotonous descending. The increase of the quantum noise with cross-correlation between the real and imaginary parts will lead to the fall of the whole curve, but not affect the form of the time evolution of C（t）.
基金Supported by the National Natural Science Foundation of China under Grant No.10275025 the Natural Science Foundation of Hubei Province of China under Grant No.2005ABA051
文摘Exact formulas for the power spectrum and signal-to-noise ratio (SNR) with periodic additive signal arecalculated in the linear system.Then the phenomenon of resonance is studied in detail.We show that resonancepeak and suppressed valley exist in the curves of the SNR versus the coefficient of self-saturation, the net gain and thecross-coupling coefficient of the laser system.
文摘By using a simple transformation approach,we solve the higher-order nonlinear Schrödinger equation under another condition.The obtained exact soliton solutions have the following prominent features:The bright soliton can propagate in both the normal and anormal regions;the soliton travelling speed is proportional to its amplitude square;the phase of the soliton is independent of its amplitude or width;and the component solitons of the bound soliton have the same phase.
