Acta Sinica Quantum Optica

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

Published Jan 1, 2008• 0 citations

Abstract

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.

Related papers

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

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

Chinese Journal of Quantum ElectronicsJan 1, 20050 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

Entropy properties in the system of a V type three-level atom interacting with the two-mode odd-even entangled coherent field

Yongping Li

The quantum reduced entropy evolution of a V-type three-level atom interacting with the two- mode odd-even entangled coherent field is investigated.The effects of the detuning,mean photon numbers of field,the atom's initial state and the degree of the entanglement of the two-mode odd-even entangled coherent fields on the entropy are discussed.The results show that the oscillation of the entropy presents collapses and revivals with the increasing of the detuning or the mean photon number.The mean-value of field entropy decreases with the increasing of the detuning.But it increases with the increasing of the mean photon number.The mean-values of field entropy are higher when the atom is initially in excited state or superposition state than that of in ground state.The mean-value and the amplitude of field entropy decrease with the increasing of the degree of the entanglement of the two-mode odd-even entangled coherent fields.

Chinese Journal of Quantum ElectronicsJan 1, 20080 citations

Evolution of atom entropy in a moving cascade three-level atom in a two-photon process

Zhang Jin-Fang, Lei Tan, Liu Li-Wei +2 more

The entropy evolution properties of field (atom) in a moving cascade three-level atom interacting with a single-mode field are studied through two photon transitions. When the atom is initially in coherent state, the influences of the atomic motion, the field-mode structure parameter and the initial average photon number on the evolution of the entropy are discussed. The results show that the entropy evolution period of the field is dependent of the atomic motion and the field-mode structure parameter. However, the parameter of the initial average photon number will neither lengthen nor shorten the entropy evolution period of the field, but the numerical values of maximum and sub-minimum of entropy will be affected by it.

Acta Physica SinicaJan 1, 20080 citations

Entropy evolution of the field interacting with a quasi-Λ-type four-level atom

Qingchun Zhou, Zhu Shi-Ning, (1)江苏科技大学数理系，镇江 212003;南京大学物理系，固体微结构物理国家重点实验室，南京 210093; (2)南京大学物理系，固体微结构物理国家重点实验室，南京 210093

The evolution of the field (atomic) entropy in a system of a quasi_Λ_type fourlevel atom interacting with an uncoupled two_mode coherent field is investigated. The effects of initial atomic state, the initial mean photon number and the splitting of the atomic energy levels on the entropy are discussed. The system reduces to that of a twolevel or threelevel atom interacting with a singlemode coherent field in special cases.

Acta Physica SinicaJan 1, 20055 citations

The field entropy evolution of the two level atom interacting with a single mode coherent light field

Pan Ying

The field entropy evolution of two level atom interacting with a single mode coherent light field is studied by means of the complete quantum theory.Through numerical calculation,the influence of the initial mean photon number,the coupled intensity g and the excited field intensity on the field entropy evolution is investigated.It is found that the field entropy evolution will be the phenomenon of oscillation periodicity and nonperiodicity and collapse-and-revival.The results show that the influence of the initial mean photon number and the coupled intensity g on the field entropy evolution possess nonlinear properties.

Journal of Northwest Normal UniversityJan 1, 20080 citations