Acta Physica Sinica

ENTROPY PROPETIES AND SCHRODINGER-CAT STATES OF THE FIELD INTERACTING WITH A Ξ TYPE THREE-LEVEL ATOM

LIU XIANG, Mao-Fa Fang, LIU AN-LING, (1)长沙电力学院，长沙 41007; (2)湖南师范大学物理系，长沙 410081

Published Jan 1, 2000• 0 citations

Abstract

In this paper, we study the entropy properties of the field interacting with a Ξ type three-level atom, derive the calculating formula of the field(atomic)ent ropy, and discuss the influence of the initial atomic state and the one-photon d etuning on the field(atomic)entropy. With the help of Q function of the field(qu asiprobability distribution), the statistical properties of the field states are discussed. It is shown that the field is in the Schrodinger-Cat state at t=12TR when the atom is initially in the middle-level.

DOI: 10.7498/aps.49.1706

Related papers

The Entropy Squeezing Properties in a System of Single-mode FieldInteracting with Ξ Type Three-level Atom

HE Jin-yu

The field entropy squeezing properties in a system of vacuum of field interacting with Ξ type three-level atom are studied. The influence of the initial state of atoms and atom-field coupling constants on the field entropy squeezing is also discussed.

Acta Sinica Quantum OpticaJan 1, 20020 citations

ENTANGLEMENT OF A GENERAL FORMALISM Ξ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

A.‐S. F. Obada, A. A. Eied, G. M. Abd Al-Kader

We investigate the evolution of the atomic quantum entropy and the atom-field entanglement in a system of a Ξ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium and the intensity-dependent coupling functional on the entropy are analyzed.

International Journal of Modern Physics BApr 10, 20094 citations

Entropy evolvement properties in a system of Schrödinger cat state light field interacting with two entangled atoms

Tang-Kun Liu

The field entropy can be regarded as a measurement of the degree of entanglement between the light field and the atoms of a system which is composed of two-level atoms initially in an entangled state interacting with the Schrödinger cat state. The influences of the strength of light field and the phase angle between the two coherent states on the field entropy are discussed by using numerical calculations. The result shows that when the strength of light field is large enough the field entropy is not zero and the degrees of entanglement between the atoms and the three different states of the light fields are equal. When the strength of the light field is small, the degree of entanglement is maximum in a system of the two entangled atoms interacting with an odd coherent state; it is intermediate for a system of the two entangled atoms interacting with the Yurke–Stoler coherent state and it is minimum in a system of the two entangled atoms interacting with an even coherent state.

Chinese PhysicsMar 1, 200611 citations

Evolution of Entropy in the Interaction of a Cascade-type Three-level Atom and Optical Field with a Time-dependent Atom-field Coupling

Zeng Xiao-xiang

Under on-resonance condition and with a time-dependent atom-field coupling,the entropy properties of the optics field interacting with a Cascade three-level atom is studied,derive the field(atomic) entropy formula and discuss the effects of the atom-field coupling coefficient and the different initial field on the field(atom) entropy at length.The result show that the different Statistical properties of the initial field will lead to the change of the field(atom) entropy.When the atom-field coupling coefficient changes slowly,the speed of atom entering the statistical state is slowed;when the atom-field coupling coefficient changes rapidly,the oscillating frequency of the evolution of entropy speed up.

Science Technology and EngineeringJan 1, 20080 citations

ENTROPY PROPERTIES OF THE FIELD OR THE ATOM IN THE INTERACTING SYSTEM OF TWO-MOD E FIELD WITH THE V-TYPE THREE-LEVEL ATOM IN A KERR-LIKE MEDIUM

Lai Zhen-jiang, Liu Zi-xin, 河南师范大学物理系，新乡 453002

Using the method of the systematic state vector we formulate the entropy of the V-type three-level atom interacting with initially uncorrelated two-mode coheren t states of arbitrary detunings in a cavity filled with Kerr-like medium. It is shown by numerical calculation that the behavior of the entropy is strongly affe cted by the Kerr medium. Weak Kerr medium improves the quantum correlation. Stro nger Kerr medium induces strongly periodic fluctuation of the quantum correlatio n between the atom and the fields.

Acta Physica SinicaJan 1, 20000 citations

Evolution of entropy in the interaction of a V-type three-level atom and single-model field with a time-dependent atom-field coupling

Tang Jing-wu

Under on-resonance condition and with a time-dependent atom-field coupling, we study the entropy properties of the field interacting with a V-type three-level atom,and discuss the effects of the atom-field coupling coefficient and the different initial field on the field (atom) entropy at length. The results show that the different statistical properties of the initial field will lead to the change of the field (atom) entropy. When the atom-field coupling coefficient changes slowly, the speed of atom entering the statistical state is slowed; When the atom-field coupling coefficient changes rapidly, the oscillating frequency of the evolution of entropy speed up.

Chinese Journal of Quantum ElectronicsJan 1, 20060 citations