量子反馈控制下不同环境双原子系统的关联演化

Correlation evolution of two atoms in different reservoirs with quantum feedback control

为了研究抑制双原子在不同环境系统中量子关联演化的退纠缠问题,在设定的初态条件下利用数学方法得到系统的时间演化密度矩阵,利用赝模理论和基于量子跃迁的量子反馈控制给出系统主方程的形式,并选取单一热库和耦合热库2个模型,采用Concurrence和量子失谐度量了系统纠缠与关联的演化规律.结果表明:在单一热库模型中,初始状态参数反馈控制的强度可以有效提高系统的稳态纠缠和关联.此外,为了进一步研究3个不同初态的关联演化,绘制出演化曲线,并给出相应的物理解释.结果表明受单一热库影响的双原子系统的量子纠缠和量子关联在最初一段时间内会发生衰减,随着时间的延长,系统的态复生最终达到稳态.与单一热库相比,耦合热库模型中,反馈控制强度对抑制系统退纠缠现象的作用不明显.

In order to study how to suppress the disentanglement problem of quantum correlation evolution of two atoms in dif-ferent environments,the time evolution of density matrix of the system was obtained by mathematical method for the given initial states.The form of the main equation of the system was presented in virtue of the pseudo-mode theory and quantum feedback control based on quantum transition,and the evolution regulation of system entanglement and correlation was measured using Concurrence and quantum discord while two models of single thermal reservoir and coupled thermal reservoirs were selected.The results show that the steady-state entanglement and quantum correlation of the system can be enhanced by the feedback control intensity in the single thermal reservoir model.Furthermore,the evolutionary curves were drawn and the corresponding physical explanations were given in order to study the correlation evolution of three different initial states.It is concluded that the quantum entanglement and quantum correlation of two atoms system influenced by the single thermal reservoir should be de-cay in initial period of time,and the steady state will finally achieve as time extends.Compared with the case of single thermal reservoir,the effect of feedback control on the suppression of disentanglement is not obvious in the coupled thermal reservoirs model.