时变耦合对含相位阻尼J-C模型线性熵的影响  

Effect of time-dependent coupling on linear entropies of the Jaynes-Cummings model with phase damping

作　　者：周青春[1] 张先寒[1] 刘生[1] 

机构地区：[1]江苏科技大学数理学院,江苏镇江212003

出　　处：《江苏科技大学学报（自然科学版）》2009年第2期179-182,共4页Journal of Jiangsu University of Science and Technology:Natural Science Edition

基　　金：江苏省高校"青蓝工程"基金资助项目(2005SL002J)

摘　　要：在腔场为相干态场,原子处于等概率叠加态的初始条件下,采用色散近似方法,研究了存在相位耗散且含与时间成正比变化的场-原子耦合的Jaynes-Cummings模型的线性熵演化特征.数值计算结果表明,与常系数耦合相比较,时变耦合不改变原子和腔场复合系统的线性熵的时间演化,但破坏原子线性熵及场线性熵的振荡周期性.在系统演化初期,时变耦合抑制并延迟原子和场相干性的丢失.耦合系数突变会显著提高子系统线性熵的振荡频率.Under the initial condition that the cavity field is in a coherent state and the atom is in the equal probability superposition of the excited and ground states, time-evolution properties of linear entropies for the Jaynes- Cummings model with time-dependent atom-field coupling proportional to interaction time in the presence of phase damping were investigated in the dispersive approximation. Numerical results indicate that compared with the constant atom-field coupling, time-dependent coupling destroys periodicity of oscillations of the atomic and the field linear entropies, but does not affect the linear entropy of the ＇ atom ＋ field＇ compound system. The time-dependent coupling suppresses and delays the coherence loss of the atom and the field during initial evolution stage of the system. Sudden jump coupling markedly increases the oscillation frequency of linear entropies of the subsystems.

关 键 词：线性熵 耗散 量子相干性 

分 类 号：O431[机械工程—光学工程]