耦合量子比特退纠缠的研究

J4 ›› 2012, Vol. 29 ›› Issue (6): 701-707.

耦合量子比特退纠缠的研究

冯斌斌¹，邹雄¹，嵇英华^1，2

1 江西师范大学物理与通信电子学院，江西南昌 330022；
2 江西省光电子与通信重点实验室，江西南昌 330022

收稿日期:2012-01-16 修回日期:2012-03-06 出版日期:2012-11-28 发布日期:2014-03-20
通讯作者: 嵇英华(1960-)江西临川人，教授，主要研究方向为量子信息。 E-mail:jxsdjyh@yahoo.com
作者简介:冯斌斌 (1985-)江西都昌人，研究生，主要从事量子计算与量子信息的研究。E-mail: fbb317@163.com
基金资助:
国家自然科学基金（11164009）资助项目

Disentanglement of coupled qubits

FENG Bin-bin¹，ZOU Xiong¹，JI Ying-hua^1，2

1 College of Physics and Communication Electronics, Jiangxi Normal University, Nanchang 330022,China ;
2 Key Laboratory of Optoelectronic and Telecommunication of Jiangxi, Nanchang 330022, China

Received:2012-01-16 Revised:2012-03-06 Published:2012-11-28 Online:2014-03-20

摘要/Abstract

摘要：

在马尔科夫环境下，利用共生纠缠度，研究了耗散环境中耦合量子比特纠缠态及纠缠突然死亡的性质。研究结果表明：(1）纠缠动力学演化与系统的温度、初始纠缠度及初始量子态密切相关；（2）在一般情形下，由于环境的影响，纠缠突然死亡总会发生；通过数值模拟，发现存在一个特定的区域，在这区域内系统的纠缠度衰减的很慢。在零温度近似下，给出了具体的纠缠突然死亡条件和计算纠缠突然死亡时间的表达式。

关键词: 量子光学, 纠缠, 耦合量子比特, 马尔科夫环境, 共生纠缠度

Abstract:

In Markovian environment, the nature of entanglement dynamics and entanglement sudden death (ESD) of coupling qubits in the dissipative environment is investigated in detail using concurrence function. The results show:(1) the dynamic evolution of entanglement is closely related with temperature of the system , the initial entanglement and the initial quantum state.(2) Under normal circumstances,entanglement sudden death always occurs due to environmental effect;A specific area is found through numerical simulation,and the decay of entanglement is very slow in this region.Under the zero-temperature approximation, the specific conditions of entanglement sudden death and the equation for calculating the time of entanglement sudden death are both given.

Key words: quantum optics, entanglement, coupled qubits, Markovian environment, concurrence

中图分类号:

0431.2

冯斌斌，邹雄，嵇英华. 耦合量子比特退纠缠的研究[J]. J4, 2012, 29(6): 701-707.

FENG Bin-bin，ZOU Xiong，JI Ying-hua. Disentanglement of coupled qubits[J]. J4, 2012, 29(6): 701-707.

参考文献

[1] Benatti F,Floreanini R.Entangling oscillators through environment noise[J].J. Phys.A,2006,39(11): 2689-2699.
[2] Cong Shuang, Lou Yuesheng.Decoherence and control strategies in open qutanum systems[J].Chinese Journal of Quantum Electronics（量子电子学报）, 2008,25(6):665-669(in Chinese).
[3] Ji Yinghua, Xu Lin. Entanglement decoherence of coupled superconductor qubits entangled states in non-Markovian environment [J]. Chinese Journal of Quantum Electronics（量子电子学报）, 2011, 28(1): 58-64(in Chinese).
[4] Zhang J,Li C W,Wu R B,Tarn T J,and Liu X S .Maximal suppression of decoherence in Markovian quantum systems [J]. Phys.A：Math.Gen, 2005, 38: 6587.
[5] Yu T,Eberly J H .Finite-time disentanglement vis spontaneous emission [J]. Phys. Rev.Lett, 2004, 93(14):140404.
[6] Yu T, Eberly J H.Sudden death of entanglement [J].Science, 2009, 323(5914):598-601.
[7] Ji Y H, Hu J J. Entanglement and decoherence of coupled superconductor qubits in a non-Markovian environment [J] .2010 ,Chin. Phys. B ,19:060304.
[8] Le Hur K, Doucet-Beaupre P, Hofstetter W. Entanglement and criticality in quantum impurity systems [J]. Phys. Rev. Lett., 2007, 99(12): 126801.
[9] Ji Y H, Liu Y M, Wang Z S. Avoiding the decay of entanglement for coupling two-qubit system interacting with a non-Markov environment [J]. Chin. Phys. B, 2011, 20: 070304.
[10] Ikram M, Li F L,and Zubairy M S.Disentanglement in a two-qubit system subjected to dissipation environments [J]. Phys .Rev .A, 2007，75(6): 062336.
[11] Cui W,Xi Z R and Pan Y.The entanglement dynamics of bipartite quantum system:Toward entanglement sudden death [J]. Phys.Rev .A, 2008, 77: 032117.
[12] Du Ming-di,Liu Xiang. Sudden death of entanglement between two atoms in two detuning cavities[J]. Chinese Journal of Quantum Electronics（量子电子学报）, 2009, 26(2): 218-222(in Chinese).
[13] Zou Yan.Entanglement properties in the system of atoms in Bell states interacting with the two-mode odd-even entangled coherent field [J]. Chinese Journal of Quantum Electronics（量子电子学报）2009,26(1):69-75(in Chinese).
[14] Yu T, Eberly J H. Sudden Death of Entanglement: Classical Noise Effects [J].Phys. Opt.Comm, 2006, 264(2):393-397.
[15] Villares Ferrer A,and Morais Smith C .Dynamical localization of a particle coupled to a two-level system thermal reservoir [J].Phys.Rev.B ,2007,76:214304.