非旋波近似下有外加驱动场时二态量子系统的退相干性

J4 ›› 2011, Vol. 28 ›› Issue (6): 705-709.

非旋波近似下有外加驱动场时二态量子系统的退相干性

张成强¹, 姬长建¹, 刘萌¹, 谭霞², 李华¹

1 齐鲁师范学院物理系, 山东济南 250200；
2 潍坊学院物理与电子科学学院, 山东潍坊 261061

收稿日期:2011-01-10 修回日期:2011-05-05 出版日期:2011-11-28 发布日期:2011-11-14
通讯作者: 张成强（1980—）山东济南人，讲师，主要从事量子光学与量子信息研究。 E-mail:hengiang@163.com

Decoherence in two-state quantun systems through an external controllable driving field without rotating wave approximation

ZHANG Cheng-qiang¹, JI Chang-jian¹, LIU Meng¹, TAN Xia², LI Hua¹

1 Department of Physics, Qilu Normal University, Jinan 250200, China;
2 College of Physics and Electronics, Weifang University, Weifang 261061, China

Received:2011-01-10 Revised:2011-05-05 Published:2011-11-28 Online:2011-11-14

摘要/Abstract

摘要：

采用非旋波近似，讨论了热库中二态量子系统在外加驱动场作用下的退相干性。利用系统的演化酉算符，计算出了二态量子系统的约化密度矩阵非对角矩阵元。结果表明：二态量子系统的量子相干性与其初始状态、热库和外加驱动场的频率、二态量子系统与热库和驱动场的耦合强度等因素有关。确定了外加驱动场与退相干性之间的关系，并得到了外加驱动场的时间演化满足特定条件时，可保持系统的相干性。

关键词: 量子光学, 退相干, 非旋波近似, 二态量子系统, 外加驱动场

Abstract:

The problem of the decoherence of two-state quantum systems interacting with a bath through an external controllable driving field without rotating wave approximation is discussed. The off-diagonal elements of the density operator in two-state quantum systems are obtained. The result reflects that the decoherence of the two-state quantum systems has something to do with its original state, frequency of the bath and frequency of the external controllable driving field. The relation between the decoherence and external controllable driving field is studied. Properties of an external controllable driving field are obtained when the two-state quantum systems of coherence is maintained.

Key words: quantum optics, decoherence, without rotating wave approximation, two-state quantum systems, external controllable driving field

中图分类号:

O431.2

张成强姬长建刘萌谭霞李华. 非旋波近似下有外加驱动场时二态量子系统的退相干性[J]. J4, 2011, 28(6): 705-709.

ZHANG Cheng-qiang, JI Chang-jian, LIU Meng, TAN Xia, LI Hua. Decoherence in two-state quantun systems through an external controllable driving field without rotating wave approximation[J]. J4, 2011, 28(6): 705-709.

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