中国物理B ›› 2012, Vol. 21 ›› Issue (11): 110304-110304.doi: 10.1088/1674-1056/21/11/110304

• GENERAL • 上一篇    下一篇

Comparison and control of the robustness between quantum entanglement and quantum correlation in open quantum system

嵇英华a b, 胡菊菊a c, 胡燕a   

  1. a Department of Physics, Jiangxi Normal University, Nanchang 330022, China;
    b Key Laboratory of Photoelectronics and Telecommunication of Jiangxi Province, Nanchang 330022, China
  • 收稿日期:2012-03-29 修回日期:2012-04-30 出版日期:2012-10-01 发布日期:2012-10-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11164009).

Comparison and control of the robustness between quantum entanglement and quantum correlation in open quantum system

Ji Ying-Hua (嵇英华)a b, Hu Ju-Ju (胡菊菊)a c, Hu Yan (胡燕 )a   

  1. a Department of Physics, Jiangxi Normal University, Nanchang 330022, China;
    b Key Laboratory of Photoelectronics and Telecommunication of Jiangxi Province, Nanchang 330022, China
  • Received:2012-03-29 Revised:2012-04-30 Online:2012-10-01 Published:2012-10-01
  • Contact: Ji Ying-Hua E-mail:ahmxhxtt@yahoo.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11164009).

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摘要： We investigate the influence of environmental decoherence on the dynamics of coupled qubit system and quantum correlation. We analyse the relationship between concurrence and the degree of initial entanglement or the purity of initial quantum state, and also their relationship with quantum discord. The results show that the decrease of the purity of initial quantum state can induce the attenuation of concurrence or quantum discord, but the attenuation of quantum discord is obviously slower than concurrence's, correspondingly the survival time of quantum discord is longer. Further investigation reveals that the robustness of quantum discord and concurrence relies on the entanglement degree of initial quantum state. The higher the degree of entanglement, the more robust the quantum discord is than concurrence. And the reverse is equally true. The birth and death happen to quantum discord periodically and a newborn quantum discord comes into being under a certain condition, so does the concurrence.

关键词: coupled qubits, non-Markovian process, entanglement, quantum discord

Abstract: We investigate the influence of environmental decoherence on the dynamics of coupled qubit system and quantum correlation. We analyse the relationship between concurrence and the degree of initial entanglement or the purity of initial quantum state, and also their relationship with quantum discord. The results show that the decrease of the purity of initial quantum state can induce the attenuation of concurrence or quantum discord, but the attenuation of quantum discord is obviously slower than concurrence's, correspondingly the survival time of quantum discord is longer. Further investigation reveals that the robustness of quantum discord and concurrence relies on the entanglement degree of initial quantum state. The higher the degree of entanglement, the more robust the quantum discord is than concurrence. And the reverse is equally true. The birth and death happen to quantum discord periodically and a newborn quantum discord comes into being under a certain condition, so does the concurrence.

Key words: coupled qubits, non-Markovian process, entanglement, quantum discord

中图分类号:  (Foundations of quantum mechanics; measurement theory)

  • 03.65.Ta
03.65.Ud (Entanglement and quantum nonlocality) 03.67.-a (Quantum information)