ACTA PHOTONICA SINICA

Study on Quantum Entropy of Field Interacting with Two Identical Entangled Atoms in Bell States

Xiaodong Zeng

Published Jan 1, 2008• 0 citations

Abstract

The evolution properties of quantum entropy of the field in the Fock state interacting resonantly with a pair of identical two-level entangled atoms in Bell states are studied by utilizing of the complete quantum theory and by the numerical method.The evolution periodicity of quantum field entropy is π/g2(2n+1)～1/2when the two atoms are initially in the first kind of Bell state.The quantum entanglement between the field and the atoms decreases with the increase of the initial field intensity,and the field is completely disentangled from the atoms when the time is a whole-number multiple of the evolution peridicity.The quantum field entropy isn't change with the time and always remains at zero when the two atoms are initially in the second kind of Bell state.The evolution curves of quantum field entropy periodically oscillates with unequal amplitude when the two atoms are initially in the third and the fourth kind of Bell state respectively,and the periodicity of the oscillation of the quantum field entropy increases with the increases of the initial photon number,while the amplitude of the oscillation decreases.The Bell states composed of a pair of identical two-level atoms can be partially distinguished based on the evolution properties of quantum field entropy above.

Related papers

Dynamical properties in the system of two identical two-level entangled atoms interacting with coherent state

Song Jun, Zhuo‐Liang Cao

In this article,the time evolution properties of the field entropy in the system of the two identical two-level entangled atoms interacting with the single-mode coherent light field are studied by means of full quantum theory.The influences of the initial states and the degree of entanglement of two identical two-level entangled atoms and the intensity of the light field on the field entropy are discussed by numerical calculations.The results show that the average value and the oscillation frequency of the field entropy increases with the increasing of the mean photon number,the oscillation of the field entropy presents stated periods in the weak light field and presents collapses and revivals in the increased light field,the amplitudes of field entropy increase with increasing initial degree of entanglement of two entangled atoms.

Chinese journal of atomic and molecular physicsJan 1, 20040 citations

Entropy properties in the system of atoms in Bell states interacting with the two-mode entangled coherent field

Zou Yan

The field entropy time evolution in Bell state|β_(01) and |β_(11) interacting with the two-mode entangled coherent field is investigated by means of full quantum theory. The effects of the atoms initial state,mean photon numbers of field,the degree of the entanglement for the entangled coherent fields,and the coupling strength of interaction between atoms on the entropy evolution properties of the field are discussed. The results shows that the entropy will forever be zero when the initial state is |β_(11) . For the state |β(01) the oscillation of the field entropy presents periodicity with the increasing of the mean photon number. And the coupling strength of interaction between atoms plays a major role in the entropy evolution properties.

Journal of Atomic and Molecular PhysicsJan 1, 20090 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

Entanglement in the System of Atoms in Bell States Interacting with the Two-mode Entangled Coherent Field Via Two-photon Process

Yongping Li

The entanglement time evolution of atoms in Bell states |β and |β interacting with the two-mode entangled coherent field is investigated by means of full quantum theory and numerical calculations.The effects of the atoms′ initial state,mean photon numbers of field,the degree of the entanglement for the entangled coherent fields,and the coupling strength of interaction between atoms on the entanglement are discussed.The results show that the entropy time evolutions appear regular with the increase of the mean photon numbers of field.The frequency and amplitude of the oscillation decrease with the increase of the coupling strength of interaction between atoms.But when the degree of the entanglement for the entangled coherent fields changes,the frequency and amplitude of the entropy oscillation won′t change.

Acta Sinica Quantum OpticaJan 1, 20080 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