中国物理B ›› 2010, Vol. 19 ›› Issue (6): 60303-060303.doi: 10.1088/1674-1056/19/6/060303

• GENERAL • 上一篇    下一篇

Sudden birth versus sudden death of entanglement for the extended Werner-like state in a dissipative environment

单传家, 陈涛, 刘继兵, 程维文, 刘堂昆, 黄燕霞, 李宏   

  1. College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China
  • 收稿日期:2009-08-30 出版日期:2010-06-15 发布日期:2010-06-15
  • 基金资助:
    Project supported by the National Natural Science Foundation, China (Grant No.~10904033), the Natural Science Foundation of Hubei Province, China (Grant No.~2009CDA145), the Science Foundation of the Educational Commission of Hubei Province, China (Grant

Sudden birth versus sudden death of entanglement for the extended Werner-like state in a dissipative environment

Shan Chuan-Jia(单传家)†, Chen Tao(陈涛), Liu Ji-Bing(刘继兵) Cheng Wei-Wen(程维文), Liu Tang-Kun(刘堂昆), Huang Yan-Xia(黄燕霞), and Li Hong(李宏)   

  1. College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China
  • Received:2009-08-30 Online:2010-06-15 Published:2010-06-15
  • Supported by:
    Project supported by the National Natural Science Foundation, China (Grant No.~10904033), the Natural Science Foundation of Hubei Province, China (Grant No.~2009CDA145), the Science Foundation of the Educational Commission of Hubei Province, China (Grant

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摘要： In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended Werner-like initial state. The interesting phenomenon of entanglement sudden death as well as sudden birth appears during the evolution process. We analyse in detail the effect of the purity of the initial entangled state of two qubits via Heisenberg XY interaction on the apparition time of entanglement sudden death and entanglement sudden birth. Furthermore, the conditions on the conversion of entanglement sudden death and entanglement sudden birth can be generalized when the initial entangled state is not pure. In particular, a critical purity of the initial mixed entangled state exists, above which entanglement sudden birth vanishes while entanglement sudden death appears. It is also noticed that stable entanglement, which is independent of different initial states of the qubits (pure or mixed state), occurs even in the presence of decoherence. These results arising from the combination of the extended Werner-like initial state and dissipative environments suggest an approach to control and enhance the entanglement even after purity induced sudden birth, death and revival.

Abstract: In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended Werner-like initial state. The interesting phenomenon of entanglement sudden death as well as sudden birth appears during the evolution process. We analyse in detail the effect of the purity of the initial entangled state of two qubits via Heisenberg XY interaction on the apparition time of entanglement sudden death and entanglement sudden birth. Furthermore, the conditions on the conversion of entanglement sudden death and entanglement sudden birth can be generalized when the initial entangled state is not pure. In particular, a critical purity of the initial mixed entangled state exists, above which entanglement sudden birth vanishes while entanglement sudden death appears. It is also noticed that stable entanglement, which is independent of different initial states of the qubits (pure or mixed state), occurs even in the presence of decoherence. These results arising from the combination of the extended Werner-like initial state and dissipative environments suggest an approach to control and enhance the entanglement even after purity induced sudden birth, death and revival.

Key words: entanglement sudden death (birth), extended Werner-like state, stable entanglement

中图分类号:  (Entanglement and quantum nonlocality)

  • 03.65.Ud
03.67.Mn (Entanglement measures, witnesses, and other characterizations) 03.67.Lx (Quantum computation architectures and implementations) 03.65.Yz (Decoherence; open systems; quantum statistical methods)