作者机构：
[Yang, YP] Tongji Univ, Dept Phys, Shanghai 200092, Peoples R China.;Hong Kong Baptist Univ, Dept Phys, Hong Kong, Hong Kong, Peoples R China.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
The interactions between a two-level atom and a coherent field with a time-varying frequency have been investigated. The two typical cases—the frequency of the field varying with time in the forms of sine and rectangle—have been considered. It is found that the collapse-revival phenomena of the atomic population inversion are deformed as the frequency changing with time in sine form and the rectangular frequency modulation can lead to some new collapses and new revivals in the evolution of the atomic population inversion.
作者机构：
[Zhu, SY] Hong Kong Baptist Univ, Dept Phys, Hong Kong, Hong Kong, Peoples R China.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Tongji Univ, Dept Phys, Shanghai 200092, Peoples R China.;Xian Jiaotong Univ, Dept Appl Phys, Xian 710049, Peoples R China.
通讯机构：
[Zhu, SY] H;Hong Kong Baptist Univ, Dept Phys, Hong Kong, Hong Kong, Peoples R China.
摘要：
The decay and radiation of an atom in a photonic crystal with an incomplete gap was investigated. If the transition frequency is close to a band edge, the Weisskopf-Wigner approximation is not applicable and the decay is nonexponential. The decay could be greatly enhanced or decreased by the self-emitted field.
作者机构：
[Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Hubei Minzhu Coll, Dept Phys, Enshi 445000, Peoples R China.
通讯机构：
[Li, GX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
原子耦合系统;量子非定域性;量子信息理论
摘要：
The property of quantum nonlocality in the atom-field coupling system via degenerate Raman processes with cavity damping is investigated. It is found that if the cavity dissipation is very weak, the atom-field state can exhibit quantum nonlocality periodically. The rapidity of the loss of the quantum nonlocality depends on the amplitude of the initial coherent state and the cavity damping constant. The stronger the field is and the larger the damping constant could be, the more rapidly the nonlocality decreases.
作者机构：
[Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China.
通讯机构：
[Li, GX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
The modification of the Autler-Townes spectrum of a V-type three-level atom driven by a strong coherent field and a weak stochastic field with a wide bandwidth is studied. It is found that the lineshape of the probe absorption spectrum varies drastically with the changing of the frequency difference between the coherent field and the stochastic one. The probe beam can be amplified due to the effect of the stochastic field and this amplification can be enhanced due to the quantum interference induced by the stochastic field. (C) 2002 Elsevier Science B.V. All rights reserved.
作者机构：
[Peng, JS; Guo, H; Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Guo, H] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
photoionization;autoionizing state;coherent population trapping
摘要：
We have investigated the photoionization properties of an atom with a ladder coupling scheme involving two autoionizing states coupled to each other. The effects of the coherent coupling between two autoionizing states and between the low-lying autoionizing state and the continuum on the ionization yield are discussed. The conditions leading to atomic coherent population trapping and the coherent population trapping states are given explicitly.
作者机构：
[Peng, JS; Guo, H; Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Guo, H] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
An analytical expression of emission spectrum for Λ-type three-level atom interacted with two-mode cavity field is given. The characters of the emission spectrum for the field in photon number state, coherent state and SU(2) coherent state are exhibited. The effects of the atomic initial state, the field property on the time-dependent physical spectrum are analyzed.
作者机构：
[Huang, GM; Wu, SP; Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Li, GX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
A scheme for generating two-mode photon-added SU(2) coherent state by means of conditional measurement is proposed. Feeding three uncorrelated Fock states into three input ports of two cascade placed lossless beam splitters respectively and counting photons in one of the output channels, the conditional state in the other two output channels is a two-mode photon-added SU(2) coherent state. The quantum nonlocality property for this state is investigated using parity measurement. (C) 2002 Elsevier Science B.V. All rights reserved.
期刊：
Journal of Modern Optics,2002年49(1-2):237-243 ISSN：0950-0340
通讯作者：
Li, GS
作者机构：
[Li, GS] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China.
通讯机构：
[Li, GS] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We show that multi-mode entangled states in which all photons are equally entangled with each other violates Bell-type inequalities indicating quantum nonlocality. The degree of nonlocality of these entangled states increases with increasing number of modes.
作者机构：
[Huang, GM; Peng, JS; Wu, SP; Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Li, GX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
A cavity-modified master equation is derived for a coherently driven V-type three-level atom coupled to a single-mode cavity in the bad cavity limit. The influences of the cavity-induced quantum interference on the steady-state populations are analysed. We show that the population inversion can occur due to the effect of cavity-induced quantum interference.
作者机构：
[Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China.
通讯机构：
[Li, GX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
The time evolution of nonlocality for atom-field entangled state in the system of a two-level atom interacting dispersively C with a single-mode field in a dissipative cavity is investigated. It is found that, if the cavity dissipation is very weak, the atom-field state can exhibits nonlocality periodically. The rapidity of the loss of the initial quantum nonlocality depends on the amplitude of the two coherent states and the cavity damping constant K. The stronger the field is and the larger the constant K, the more rapidly the nonlocality decreases. (C) 2001 Elsevier Science B.V. All rights reserved.
作者机构：
[Li, GX] Hong Kong Baptist Univ, Dept Phys, Hong Kong, Hong Kong, Peoples R China.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Xian Jiao Tong Univ, Dept Appl Phys, Xian 710049, Peoples R China.
通讯机构：
[Li, GX] H;Hong Kong Baptist Univ, Dept Phys, Hong Kong, Hong Kong, Peoples R China.
摘要：
Spontaneous emission of an atom with two close upper levels and one lower level in a multilayer dielectric medium, and quantum interference between transitions from the upper levels to the lower one, are considered. Since the medium is inhomogeneous along the direction normal to the interfaces of the dielectric layers, the vacuum has an anisotropic spatial structure, and quantum intereference between the two decay channels can appear even if the two dipole matrix elements are orthogonal to each other. If the atom is placed in a three-layer dielectric plate cavity, a strong quantum interference similar to that for an atom with two nearly parallel dipole moments in free space arises due to the influence of anisotropic vacuum. Putting the atom in a three-layer dielectric waveguide and a one-dimensional photonic crystal, there appears a strong quantum interference similar to that for an atom with nearly antiparallel dipole moments.
