J4 ›› 2012, Vol. 29 ›› Issue (5): 547-554.

• 量子光学 • 上一篇    下一篇

考虑DM相互作用的Ising系统中量子失协的含时演化

郭战营1,2, 肖瑞华1, 方建兴1   

  1. 1苏州大学物理科学与技术学院,江苏 苏州 215006; 
    2 焦作师范高等专科学校物理系,河南 焦作 454001
  • 收稿日期:2011-07-04 修回日期:2011-09-16 出版日期:2012-09-28 发布日期:2012-09-02
  • 通讯作者: 方建兴(1963-),博士生导师,教授,主要研究方向为量子信息学。 E-mail:fangjx@suda.edu.cn
  • 作者简介:郭战营(1970-),硕士,副教授,主要研究量子失协及纠缠。E-mail:guo7011@126.com
  • 基金资助:

    国家自然科学基金资助项目(11074184),河南省高校青年骨干教师资助计划项目(2009GGJS-163)

Dynamics of quantum discord for Ising system with Dzialoshinskii-Moriya interaction

GUO Zhan-ying1,2, XIAO Rui-hua1, FANG Jian-xing1?   

  1. 1 School of Physical Science and Technology, Soochow University, Suzhou 215006, China; 
    2 Department of Physics, Jiaozuo Normal College, Jiaozuo 454001, China
  • Received:2011-07-04 Revised:2011-09-16 Published:2012-09-28 Online:2012-09-02

摘要:

研究了处在非均匀磁场中的两粒子Ising系统,在考虑DM相互作用情况下,其量子失协(QD)随时间演化问题。对于初始处于Werner态的系统,详细分析了在随时间演化过程中DM相互作用、不均匀磁场的不均匀度、初态的纯度等因素对量子失协和量子纠缠的影响。通过比较可以发现,两者在很大程度上保持着相似的变化规律,最明显的不同在于演化过程中,在有限的时间内量子失协并不会消失,但是量子纠缠却会出现突然死亡现象(ESD)。这一明显不同的特征表明量子失协比量子纠缠具有更大的应用空间,通过控制外部条件,可以很好的控制量子失协随时间的演化过程。

关键词: 量子光学, 量子失协, 含时演化, Ising 系统, DM相互作用

Abstract:

The dynamics of quantum discord (QD) is investigated in the two-qubit Ising system in an inhomogeneous magnetic field with the Dzialoshinskii-Moriya (DM) interaction. The system is initially prepared in the Werner state,and the effects of the DM interaction, the degree of inhomogeneous magnetic field and the purity of the initial state on QD and the entanglement in the evolution process are analyzed in detail. By a comparison, it is found that both the quantum discord and the entanglement take similar behaviors to a large extent, and QD does not vanish in the finite time, but the phenomenon of the entanglement sudden death (ESD) appears during the evolution process. This is an interesting difference, which shows that the quantum discord is more practical than the entanglement to evaluate the quantum correlation. These effects also indicate that one can control the quantum discord of the system by some exterior conditions.

Key words: quantum optics, quantum discord, dynamics, Ising system, DM interaction

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