An accurate method to solve the daynes Cummings (J-C) Hamiltonian has been investigated here. The phenomenon of atomic collapse and revival predicted by Jaynes-Cummings model is demonstrated. Solutions are consis- t...An accurate method to solve the daynes Cummings (J-C) Hamiltonian has been investigated here. The phenomenon of atomic collapse and revival predicted by Jaynes-Cummings model is demonstrated. Solutions are consis- tent with the precious such as using the operator method. Furthermore, the Jaynes-Cummings Hamiltonian including the anti-rotating term is also solved precisely using this accurate way so that results agree with experiments better. Essences of the anti-rotating term are revealed. We discuss the relations of the phenomenon of atomic collapse and revival with the average photons number, the light field phase angle, the resonant frequency, and the size of coupling constant. The discussions may make one select suitable conditions to carry out experiment well and study the virtual light field effect on cavity quantum electrodynamics.展开更多
Considering two identical two-level atoms interacting with a single-model dissipative coherent cavity field without rotating wave approximation, we explore the entanglement dynamics of the two atoms prepared in differ...Considering two identical two-level atoms interacting with a single-model dissipative coherent cavity field without rotating wave approximation, we explore the entanglement dynamics of the two atoms prepared in different states using concurrence. Interestingly, our results show that the entanglement between the two atoms that initially disentangled will come up to a large constant rapidly, and then keeps steady in the following time or always has its maximum when prepared in some special Bell states. The model considered in this study is a good candidate for quantum information processing especially for quantum computation as steady high-degree atomic entanglement resource obtained in dissipative cavit.展开更多
In the limit of weak coupling between a system and its reservoir,we derive the time-convolutionless(TCL) nonMarkovian master equation for a two-level system interacting with a zero-temperature structured environment...In the limit of weak coupling between a system and its reservoir,we derive the time-convolutionless(TCL) nonMarkovian master equation for a two-level system interacting with a zero-temperature structured environment with no rotating wave approximation(NRWA).By comparing the dynamics with RWA,we demonstrate the impact of RWA on the system dynamics,as well as the effects of non-Markovianity on the preservation of atomic coherence,squeezing,and entanglement.展开更多
We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply...We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply the rotating wave approximation in a driven high-spin system is to assume the dynamics being restricted in the reduced Hilbert space.However,when the driving strength is relatively strong or the driving is off resonant,the leakage from the target resonance subspace cannot be neglected for a multi-level quantum system.We propose the correct formalism to apply the rotating wave approximation in the full Hilbert space by taking this leakage into account.By estimating the operator fidelity of the time propagator,our formalism applied in the full Hilbert space unambiguously manifests great advantages over the conventional method applied in the reduced Hilbert space.展开更多
Quantum state discrimination is an important part of quantum information processing.We investigate the discrimination of coherent states through a Jaynes-Cummings(JC)model interaction between the field and the ancilla...Quantum state discrimination is an important part of quantum information processing.We investigate the discrimination of coherent states through a Jaynes-Cummings(JC)model interaction between the field and the ancilla without rotation wave approximation(RWA).We show that the minimum failure probability can be reduced as RWA is eliminated from the JC model and the non-RWA terms accompanied by the quantum effects of fields(e.g.the virtualphoton process in the JC model without RWA)can enhance the state discrimination.The JC model without RWA for unambiguous state discrimination is superior to ambiguous state discrimination,particularly when the number of sequential measurements increases.Unambiguous state discrimination implemented via the non-RWA JC model is beneficial to saving resource costs.展开更多
The time evolution of system in two photon Jaynes Cummings (J C) model without rotating waves approximation (RWA) is obtained by using the theory of ordinary differential equations. Based on the evolution, the mean ...The time evolution of system in two photon Jaynes Cummings (J C) model without rotating waves approximation (RWA) is obtained by using the theory of ordinary differential equations. Based on the evolution, the mean value of the atom inversion operator 〈 S 3(t)〉 is gi ven. The influence of the “counter rotating term” on the collapse and revival phenomenon is discussed from the comparison between the cases with RWA and without RWA. It shows that the influence of the virtual photon field makes the quantum fluctuations appear on the collapse and revival phenomenon.展开更多
Nonlinearity has a crucial impact on the symmetry properties of dynamical systems. This paper studies a one-dimensional mixed Klein-Gordon/Fermi Pasta-Ulam diatomic chain using the expanded rotating plane-wave approxi...Nonlinearity has a crucial impact on the symmetry properties of dynamical systems. This paper studies a one-dimensional mixed Klein-Gordon/Fermi Pasta-Ulam diatomic chain using the expanded rotating plane-wave approximation and numerical calculations to determine the effect of cubic potentials on the symmetry properties of discrete breathers in this system. The results will be very useful to researchers in the field of numerical calculations on discrete breathers.展开更多
基金Supported by the Natural Science Foundation of Hunan Province under Grant No.09JJ6011the Natural Science Foundation of Education Department of Hunan Province under Grant Nos.10A100 and 07C528
文摘An accurate method to solve the daynes Cummings (J-C) Hamiltonian has been investigated here. The phenomenon of atomic collapse and revival predicted by Jaynes-Cummings model is demonstrated. Solutions are consis- tent with the precious such as using the operator method. Furthermore, the Jaynes-Cummings Hamiltonian including the anti-rotating term is also solved precisely using this accurate way so that results agree with experiments better. Essences of the anti-rotating term are revealed. We discuss the relations of the phenomenon of atomic collapse and revival with the average photons number, the light field phase angle, the resonant frequency, and the size of coupling constant. The discussions may make one select suitable conditions to carry out experiment well and study the virtual light field effect on cavity quantum electrodynamics.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10374025)the Education Ministry of Hunan Province,China (Grant No. 06A038)the Natural Science Foundation of Hunan Province,China (Grant No. 07JJ3013
文摘Considering two identical two-level atoms interacting with a single-model dissipative coherent cavity field without rotating wave approximation, we explore the entanglement dynamics of the two atoms prepared in different states using concurrence. Interestingly, our results show that the entanglement between the two atoms that initially disentangled will come up to a large constant rapidly, and then keeps steady in the following time or always has its maximum when prepared in some special Bell states. The model considered in this study is a good candidate for quantum information processing especially for quantum computation as steady high-degree atomic entanglement resource obtained in dissipative cavit.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11275064 and 11075050)the National Basic Research Program of China(Grant No. 2007CB925204)the Construct Program of the National Key Discipline,China
文摘In the limit of weak coupling between a system and its reservoir,we derive the time-convolutionless(TCL) nonMarkovian master equation for a two-level system interacting with a zero-temperature structured environment with no rotating wave approximation(NRWA).By comparing the dynamics with RWA,we demonstrate the impact of RWA on the system dynamics,as well as the effects of non-Markovianity on the preservation of atomic coherence,squeezing,and entanglement.
基金the National Key Research and Development Program of China(Grant Nos.2017YFA0304202 and 2017YFA0205700)the National Natural Science Foundation of China(Grant Nos.11875231 and 11935012)the Fundamental Research Funds for the Central Universities(Grant No.2018FZA3005).
文摘We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply the rotating wave approximation in a driven high-spin system is to assume the dynamics being restricted in the reduced Hilbert space.However,when the driving strength is relatively strong or the driving is off resonant,the leakage from the target resonance subspace cannot be neglected for a multi-level quantum system.We propose the correct formalism to apply the rotating wave approximation in the full Hilbert space by taking this leakage into account.By estimating the operator fidelity of the time propagator,our formalism applied in the full Hilbert space unambiguously manifests great advantages over the conventional method applied in the reduced Hilbert space.
基金funded by the NSF of China(Grant Nos.11675119,12075159,11575125,12171044)Shanxi Education Department Fund(2020L0543)+3 种基金Beijing Natural Science Foundation(Z190005)Academy for Multidisciplinary Studies,Capital Normal Universitythe Academician Innovation Platform of Hainan Provincethe Shenzhen Institute for Quantum Science and Engineering,Southern University of Science and Technology(No.SIQSE202001)
文摘Quantum state discrimination is an important part of quantum information processing.We investigate the discrimination of coherent states through a Jaynes-Cummings(JC)model interaction between the field and the ancilla without rotation wave approximation(RWA).We show that the minimum failure probability can be reduced as RWA is eliminated from the JC model and the non-RWA terms accompanied by the quantum effects of fields(e.g.the virtualphoton process in the JC model without RWA)can enhance the state discrimination.The JC model without RWA for unambiguous state discrimination is superior to ambiguous state discrimination,particularly when the number of sequential measurements increases.Unambiguous state discrimination implemented via the non-RWA JC model is beneficial to saving resource costs.
文摘The time evolution of system in two photon Jaynes Cummings (J C) model without rotating waves approximation (RWA) is obtained by using the theory of ordinary differential equations. Based on the evolution, the mean value of the atom inversion operator 〈 S 3(t)〉 is gi ven. The influence of the “counter rotating term” on the collapse and revival phenomenon is discussed from the comparison between the cases with RWA and without RWA. It shows that the influence of the virtual photon field makes the quantum fluctuations appear on the collapse and revival phenomenon.
基金Project supported by the National Natural Science Foundation of China (Grant No.10574011)the Foundation for Innovative Research Groups Foundation of Beijing Normal University
文摘Nonlinearity has a crucial impact on the symmetry properties of dynamical systems. This paper studies a one-dimensional mixed Klein-Gordon/Fermi Pasta-Ulam diatomic chain using the expanded rotating plane-wave approximation and numerical calculations to determine the effect of cubic potentials on the symmetry properties of discrete breathers in this system. The results will be very useful to researchers in the field of numerical calculations on discrete breathers.