Chinese Journal of Quantum Electronics

Evolution properties of the field entropy in the system of the SU(1,1) coherent states field interacting with a four-level atom

Zhong Shu-ying

Published Jan 1, 2005• 0 citations

Abstract

Using the method of the systematic state vector the field entropy of the two-mode SU(1,1) coherent states field interacting with four-level atom has been formulated.The influences of the initial field strength and the atom-field coupling constant on the field entropy have been investigated. The results obtained by means of numerical show that. With the increase of the initial field parameter q and ζ, the mean values of the evolution curves of the field entropy increase constantly and so do the oscillation frequency of the evolution curves of the field entropy. The larger the value of ζ is. the more obvious the periodicity of the evolution curves of the initial field entropy are, but the obviously smaller the oscillation amplitude values become. With the increase of the coupling constant, the mean values of the evolution curves of the field entropy do not obviously change, but the oscillation frequency increase largely, the oscillation amplitude decrease a little and get to stability after some time, This shows that the field entropy is susceptible to the atom-field coupling constant

Related papers

Properties of field quantum entropy evolution in the Jaynes–Cummings model with initial squeezed coherent states field

Liu Wang-Yun, Yuying An, Yang Zhi-yong

The properties of the field quantum entropy evolution in a system of a single-mode squeezed coherent state field interacting with a two-level atom is studied by utilizing the complete quantum theory, and we focus our attention on the discussion of the influences of field squeezing parameter γ, atomic distribution angle θ and coupling strength g between the field and the atom on the properties of the evolution of field quantum entropy. The results obtained from numerical calculation indicate that the amplitude of oscillation of field quantum entropy evolution decreases with the increasing of squeezing parameter γ, and that both atomic distribution angle θ and coupling strength g between the field and the atom can influence the periodicity of field quantum entropy evolution.

Chinese PhysicsDec 1, 20078 citations

Evolution of the Entropy of the Field in a System of Λ-type Three-level Atom Interacting with Two-mode SU(2) Coherent field

LU Dao-ming

Evolution of the entropy of the field in a system of Λ-type three-level atom interacting with two-mode SU(2) coherent field is studied.The influences of atom-field coulping strengths,the maximum possible number of photons in both modes N and a complex parameter related to the partition of photons in the SU(2) coherent state field modes ξ on evolution of the entropy of the field are discussed.The results obtained using the numerical method show that when atom-field coulping strengths g1 and g2 are nearly equel,evolution of the entropy of the field displays periodic oscillation;when the difference between atom-field coulping strength g1 and g2 is obvious,evolution of the entropy of the field displays collapse and revival phenomena.On the other hand,the times of collapses increases with the increase of the maximum possible number of photons in both modes N and with the decrease of the ratio between atom-field coulping strength of two single-mode l and a complex parameter related to the partition of photons in the SU(2) coherent state field modes ξ.

Acta Sinica Quantum OpticaJan 1, 20080 citations

Evolution of the Field Entropy in the Interaction of the Two-Mode SU(1,1)Coherent States Field with Four-Level Atom Added Kerr-Like Medium

Zhong Shu

Using the method of the systematic state vector the field entropy of the two_mode SU(1,1)coherent states field interacting with four_level atom added Kerr_like medium has been formulated.The influences of the Kerr effect and the initial field strength on the field entropy have been investigated.

Jiangxi kexueJan 1, 20040 citations

Quantum field-entropy evolution properties in system of coupled two-level atoms interacting with a single-mode odd-coherent state light field

Wang Ju-xia, Yang Zhi-yong

According to the complete quantum theory,the quantum field-entropy evolution properties in a system of the two coupled two-level atoms interacting with a single-mode odd-coherent state light field are studied.Through numerical calculation the influence of the initial mean photon number n_0,the coupled intensity g of interaction between the single-mode field and atoms,and the coupled intensity g_a of dipole-dipole interaction between the two coupled atoms on the quantum field-entropy evolving while the initial state of the light field is a single-mode odd-coherent and the two coupled two-level atoms lay in different Einstein Poclolsky Rosen(EPR) entangled state respectively.The results indicate that the time evolving of quantum field-entropy is closely related to the initial atoms state.The quantum field-entropy evolution can display the phenomena of entanglement and disentanglement while they are periodically under the condition of intensity field(n_01). Meanwhile the phenomena of quantum interference is also discovered.The periodicity of the quantum field-entropy anomalous oscillation decreases gradually with the increasing of g values.When g_a is an especial constant,it is shown that the phenomena of period collapse-reversion can present.

Journal of Shaanxi Normal UniversityJan 1, 20060 citations

Properties of Evolution of Quantum Field Entropy in a Single-mode Vacuum Field-Coupled Two-level Atoms′ System

Yuying An

The properties of quantum field entropy evolution in a single-mode vacuum field-coupled two-level atoms′ system were by the complete quantum theory.The numerical results indicate that the quantum field entropy in the system is periodic oscillation with two peaks′ or many peaks′ structures;The quantum entanglement between the atoms decreases with the increase of the dipole-dipole interaction strength between them;The amplitude of the field quantum entropy decreases with the increase of the probability of the two atoms stayed simultaneously in their ground states;Especially when the two atoms both stayed in their ground states,the field and the atoms are both disentangled for a long time;The coupling strength between the field and the atoms has important influences on the periodicity of the field quantum entropy,namely,the periodicity mentioned above becomes shorter with the strengther of the coupling.

Journal of Optoelectronics·laserJan 1, 20070 citations

The quantum field entropy in the system of a squeezed coherent states field interacting with two coupled two-level atoms

Xiaowei Han

The properties of quantum field entropy evolution in the system of a single-mode squeezed coherent states field interacting with a pair of identical coupled two-level atoms is studied by utilizing of the complete quantum theory,and the influences of the field squeezing parameter,the coupling strength between the field and the atoms and the coupling strength between the two identical two-level atoms on properties of evolution of quantum field entropy are discussed.The results obtained from the numerical results indicate that the field squeezing parameter influences the amplitude of vibration of the field quantum entropy evolution,the coupling strength between the field and the atoms affects the periodicity of the evolution of the field quantum entropy,while the coupling strength between the two identical two-level atoms influences not only the amplitude of the oscillation of the field quantum entropy evolution but also its periodicity.

Journal of Shaanxi Normal UniversityJan 1, 20080 citations