双模相干场与Bell态原子多光子作用的原子布居数演化

Time-evolution of the atom's occupancy of two-mode field interacting with two atoms in Bell states via multiphoton process

应用全量子理论研究了非关联双模相干场与Bell态原子多光子相互作用过程中原子粒子布居差的时间演化规律。结果表明,当两原子初始处于(1/2^(1/2))(|+,-〉-|-,+〉)态时,原子粒子布居差恒为零；当两原子初始时刻的状态为其它三个Bell态时,原子粒子布居差的时间演化强烈依赖于原子间的偶极-偶极相互作用强度、场-原子间的耦合系数以及原子的跃迁光子数。随着原子间的偶极-偶极相互作用的增强,原子跃迁光子数的增加,原子布居差的时间演化中,Rabi振荡的频率都会明显加快,并且当原子间的偶极-偶极相互作用强度足够大时,原子布居差的崩塌-回复现象就会消失。

We investigate the time-evolution of the atom＇s occupancy in the system of twomode coherent fields interacting with two atoms in Bell states via multiphoton process. The results show that the atom＇s occupancy is zero if the two atoms are initially in Bell state 1/√2（｜＋,-〉 - ｜-,＋〉）. The atom＇s occupancy is influenced by three factors, which are the intensity of two dipole-dipole coupled atoms, the coupling constant of light and atoms and the absorbing or emitting photon number per atomic transition, if the two atoms are initially in the other three Bell states. The oscillation frequency of the atom＇s occupancy accelerates apparently with the increase of the intensity of two dipole-dipole coupled atoms or the absorbing or emitting photon number per atomic transition. The collapse-revival phenomenon of the atom＇s occupancy disappears when the intensity of two dipole-dipole coupled atoms is increased to some point.