Journal of Jilin University(Science Edition)

Evolution of Atomic Population in System of Two-mode Entangled Coherent Field Interacting with Atoms in Bell States in Kerr Medium

Zhuo‐Liang Cao

Published Jan 1, 2007• 0 citations

Abstract

The time evolution of atomic population of the system, where the two identical two-level atoms in Bell states interact with two-mode entangled coherent field in a cavity filled with the Kerr medium, was investigated by means of quantum theory and numerical method. The effects of the atomic initial state, mean photon numbers of field, the degree of the entanglement for the entangled coherent field, and the coupling strength between the Kerr medium and field on the atom’s population are discussed via numerical calculations. The results show that the atomic population is time-independent provided that the atoms are in β11〉 state. For the other three Bell states, there will appear the periodical collapse-revival of atomic population if the initial mean photon number reaches some special values. With the increase of the initial mean photon number, the oscillation frequency of the time-evolution of atomic population increases correspondingly, and the amplitude decreases. The degree of the entanglement of the two-mode entangled coherent field has no effect on the frequency of the Rabi oscillation, but has an obvious effect on the amplitude of Rabi oscillation. When the coupling strength between the Kerr medium and field reaches some special values, it has the obvious effects on the cycle of collapse-revival of atomic population, the frequency and the amplitude of Rabi oscillation.

Related papers

The Time-evolution of the Atomic Population in the System of Atoms in Bell States Interacting with Two-mode Entangled Coherent Field

Zhuo‐Liang Cao

The time-evolution of atomic population of a light-atoms interaction system,two atoms in Bell states Interacting with two-mode entangled coherent field,are investigated by means of quantum thoery and numerical method.The effect of the atomic initial state,mean photon numbers of field,the degree of the entanglment for the entangled coherent fields,and the coupling strength of dipole-dipole interaction between atoms on the atom's population are discussed by numerical calculation.The results show that the atomic population is time-independent provided that the atom is in |β11〉 state.For the other three Bell states,there will appear the periodical collapse-revival of the atomic population if the initial mean photon number reaches some special value.With the increase of the initial mean photon number,the oscillation frequency of the time-evolution of atomic population increases correspondingly,and the amplitude decreases.The revival period of the atomic population for the initial states |β00〉 and |β10〉 is twice of that for the initial state |β01〉.The degree of entanglement of the two-mode entangled coherent field and the intensity of two dipole-dipole interaction between atoms have no effects on the frequency of the Rabi oscillation,but have obvious effects on the amplitude of the oscillation.

Acta Sinica Quantum OpticaJan 1, 20070 citations

Time-evolution of the Atom's Occupancy of Atoms in Bell States Interacting with the Two-mode Entangled Coherent Field via Two-photon Process

Yongping Li

The time-evolution of the atom′s occupancy in the system of two-mode entangled coherent fields interacting with two atoms in Bell states via two-photon process is investigated by means of quantum theory.The results show that the atom′s occupancy is zero if the two atoms are initially in Bell state |β11.If the two atoms are initially in the other three Bell states,the oscillation frequency of the atom′s occupancy accelerates and the amplitude decreases apparently with the increase of mean photon numbers of field.The degree of the entanglement for the entangled coherent fields can′t influence the oscillation frequency and the position of the atom′s occupancy curve.If the two atoms are initially in Bell state |β01,the Rabi oscillation frequency of the atom′s occupancy accelerates apparently with the increase of the coupling strength of interaction between atoms.While the two atoms are initially in Bell state |β10 or |β00,the collapse-revival phenomenon of the atom′s occupancy disappears gradually.

Acta Sinica Quantum OpticaJan 1, 20080 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

Dipole squeezing in the system of the two-mode entangled coherent field interacting with atoms in Bell states in Kerr medium

Lin Ji-Cheng, Zheng Xiao-hu, Zhuo‐Liang Cao +1 more

The atomic dipole squeezing effect in the system of two identical two-level atoms in the Bell state interacting with the two-mode entangled coherent state field in Kerr medium are investigated by means of solving the Schrdinger equation and numerical calculations. The effects on the atomic dipole squeezing effect produced by the atomic initial state, mean photon number of light field, the degree of the entanglement of the entangled coherent field, the coupling strength of the Kerr medium with the light field and the coupling strength of dipole-dipole interaction between atoms are discussed. The results show that the dipole squeezing effect does not appear for the Bell state |β11>, while there can be dipole squeezing effect under certain conditions for the Bell states |β00> or |β01> or |β10>. In the latter case, the dipole squeezing effect depends on the coupling strength of the Kerr medium with the light field, the mean photon number and the degree of entanglement of the two-mode entangled coherent field.

Acta Physica SinicaJan 1, 20075 citations

Statistic properties of photon in the system of a two-mode odd-even entangled coherent states field interacting with atom in Kerr medium

Fang Shu-dong, Zhuo‐Liang Cao

The statistic properties of photon in the system of a two-mode odd-even entangled coherent states field interacting with a V-type three-level atom in Kerr medium are investi- gated by solving Schr dinger equation and numerical calculations.The effects on the statistic properties of photon induced by the degree of entanglement of the two-mode odd-even en- tangled coherent states field,the coupling strength of the Kerr medium with the light field, the mean photon numbers and the ground state probability amplitude of atomic initial state are analyzed.The results indicate that the influence of the degree of entanglement of the two-mode odd-even entangled coherent states fields on the statistic properties of photon isn't noticeable.But the enhancing of Kerr effect,the decreasing of mean photon numbers and the increasing of the ground state probability amplitude of atomic initial state cause the time evolution curves to move up or down distinctly.The enhancing of Kerr effect results in the increase of the oscillating frequency of the curve and the decrease of the oscillating amplitude of the curve.When the mean photon numbers of the mode 1 remain unchanged and the mean photon numbers of the mode 2 are decreased,the oscillating amplitude of the curve is increased.

Chinese Journal of Quantum ElectronicsJan 1, 20070 citations

Statistic properties of photon in the system of two coupling atoms interacting with two-mode squeezed vacuum field in Kerr medium

Fang Jia-Yuan, Huang Chun-Jia, Huang Zu-hong +2 more

The statistic properties of photons in the system of two-mode squeezing vacuum field interacting with two coupling atoms in Kerr medium are studied by means of quantum theory.The influences of coupling constant χ, initial squeezed parameter r and the atomic initial state are discussed. The results obtained by means of numerical method show that the photon bunching and anti-bunching appear alternately, and the correlation of the two modes of light is both positive and non-classical. The periodical collapse-revival phenomenon of the time evolution of the second-order coherence degree of the two-mode field appears due to the influence of the Kerr effect. The periods of the collapse-revival become short up to disappearance with increasing Kerr effect.

Acta Physica SinicaJan 1, 20040 citations