腔中Λ型原子与光场Raman相互作用体系的熵特性  

Entropy Properties of Atom-Field System with Raman Coupling In a Cavity

作　　者：赖振讲[1] 韩哲[1] 赖小伟[2] 常俊巍[1] 

机构地区：[1]河南师范大学物理与信息工程学院,河南新乡453007 [2]河南师范大学新联学院,河南新乡453007

出　　处：《河南师范大学学报（自然科学版）》2011年第6期39-43,共5页Journal of Henan Normal University(Natural Science Edition)

基　　金：河南省自然科学基金(082300410030);河南省教育厅自然科学基金项目(2011A140011)

摘　　要：利用描述环境作用的超算符方法对耗散腔中型三能级原子与光场Raman相互作用体系的主方程进行了精确求解;计算了原子、光场以及系统的线性熵,讨论了光场强度、腔的耗散系数以及原子两能级的Stark位移对线性熵的影响.结果发现:光场越强,光场与其它子系统进行熵交换的时间越长;腔耗散系数阻滞子系统间的熵交换;使系统的熵不可逆的增加,相干信息量减少;并使光场与环境发生熵交换,最后趋于零.两能级之间的Stark位移增强原子和场之间的耦合,当系统的耗散系数不变时,使系统的熵交换加快和稳态值变小.当腔的耗散系数为零时,原子与光相互作用时出现崩塌与复原特性,线性熵表现为饱和与退饱和现象.随着原子数的增加,在饱和与退饱和时段熵演化特性变得越来越复杂.Using the method of super-operator that describes the dissipative effects, the study has obtained exact solution of the master equation that represents a Raman interaction between three-level atoms and cavity-field. The linear entropy of the system, along with atoms and cavity-field in the system is formulated. The influences of the Stark shift between two atomic levels, intensity of the cavity-field and the dissipative coefficient of the cavity on the linear entropy are discussed. It is found that the more intense the cavity-field, the longer the persistent time of the exchange of entropy between the cavity field and atoms. Because the cavity field leaks, the cavity dissipation blocks entropy exchange between the subsystems; to make the entropy of the system and subsystem increase irreversibly and reduce the amount of the coherent information, and so that it is finally to zero. When the Stark shifts between the atomic levels changes and the cavity dissipation coefficient remain has unchanged, the coupling between atom and cavity field enhances, the entropy exchange of the system speed up and the steady-state values become smaller. When the dissipation of the cavity is absent, the entropy of the light field and the atoms follow the same evolutionary regularity and reversible, show saturated and retreat saturated natures corresponding to the collapse and restoration of the atomic levels, respectively. Along with the increase of atomic number in saturated and retreat saturated time the entropy evolution characteristics is becoming more and more complicated.

关 键 词：Λ型三能级原子 线性熵 幅值耗散腔 STARK位移 

分 类 号：O431.2[机械工程—光学工程]