精确求解级联型三能级原子与单模相干态光场场熵的演化特性  

An exact solution of evolution of the field entropy in a system of three-level cascade type atom interacting with single-mode coherent field

作　　者：丛红璐[1] 任学藻[1] 姜道来[1] 廖旭[1] 

机构地区：[1]西南科技大学理学院,绵阳621010

出　　处：《物理学报》2010年第5期3221-3226,共6页Acta Physica Sinica

基　　金：四川省自然科学基金(批准号:2006C028)资助的课题~~

摘　　要：本文利用全量子理论,在非旋波近似下对单模相干态光场与级联型三能级原子相互作用过程中场熵随时间的演化进行了精确求解.数值计算的结果表明:随着初始时刻平均光子数■以及光场与原子的耦合强度u,v的增大,场熵的平均值先增大后减小,因此纠缠度也同样先增大后减小;随着失谐量Δ的增大,场熵的平均值逐渐减小,因此纠缠度也逐渐减小.In this paper,the evolution of field entropy in the system of single-mode coherent light field interacting with a three-level cascade type atom is calculated exactly in the frame of complete quantum theory and without rotating wave approximation. The numerical results indicate that with the increases of the initial mean photon number  and the atom-field coupling strengths u and v the mean value of the field entropy increases at first and then decreases. Therefore,the degrees of entanglement also increase at first and then decrease. The mean value of the entropy of the field decreases with the enlarging of the detuning Δ,which leads to the decrease of the degrees of entanglement.

关 键 词：相干态正交化展开 非旋波近似 场熵 

分 类 号：O431.2[机械工程—光学工程]