腔QED中混态双原子系统原子布居数演化

Evolution of atom's occupancy of two-atom system at mixed state in cavity QED

运用全量子理论和数值计算方法,研究了双J-C模型中处于混态的双原子系统粒子布居差的时间演化规律,讨论了原子初态及腔内光场对粒子布居差演化的影响。计算结果表明:当两腔内的平均光子数相同时,布居差的演化只与两原子的初态纯度和光场强度有关,与两原子的初始纠缠无关;而当两光腔内的平均光子数不同时,粒子布居差演化不仅与两原子初态纯度和腔内光场有关,而且还强烈地依赖于两原子的初始纠缠。

The time evolution of atom’s occupation in a double Jaynes-Cummings model,where two atoms are in mixed state,was investigated by full quantum theory and numerical method,and the influences of atomic initial state and mean photon number in cavity on atom’s occupancy are discussed.The results show when the two cavities have the same photon number,evolution of atom’s occupation is only related to the purity r of atomic initial state and field intensity,but not influenced by initial entanglement.If the mean photon number in cavities is not equal,the evolution of atom’s occupation is not only related to the purity r and field intensity,but also strongly influenced by the initial entanglement.