Chin. Phys. B ›› 2013, Vol. 22 ›› Issue (2): 20305-020305.doi: 10.1088/1674-1056/22/2/020305

• GENERAL • 上一篇    下一篇

Investigations on quantum correlation of coupled qubits in squeezed vacuum reservoir

嵇英华a c, 刘咏梅b   

  1. a Department of Physics, Jiangxi Normal University, Nanchang 330022, China;
    b College of Mathematics and Information Science, Jiangxi Normal University, Nanchang 330022, China;
    c Key Laboratory of Photoelectronics and Telecommunication of Jiangxi Province, Nanchang 330022, China
  • 收稿日期:2012-04-20 修回日期:2012-07-10 出版日期:2013-01-01 发布日期:2013-01-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11164009).

Investigations on quantum correlation of coupled qubits in squeezed vacuum reservoir

Ji Ying-Hua (嵇英华)a c, Liu Yong-Mei (刘咏梅)b   

  1. a Department of Physics, Jiangxi Normal University, Nanchang 330022, China;
    b College of Mathematics and Information Science, Jiangxi Normal University, Nanchang 330022, China;
    c Key Laboratory of Photoelectronics and Telecommunication of Jiangxi Province, Nanchang 330022, China
  • Received:2012-04-20 Revised:2012-07-10 Online:2013-01-01 Published:2013-01-01
  • 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： In this paper, we investigate the quantum correlation of coupled qubits which are initially in maximally entangled mixed states in squeezed vacuum reservoir. We compare and analyse the effects of squeezed parameters on quantum discord and quantum concurrence. The results show that in squeezed vacuum reservoir, the quantum discord and quantum concurrence perform completely opposite behaviors to the change of squeezed parameters. Quantum discord survives longer with the increase of squeezed amplitude parameter, but entanglement death turns faster on the contrary. The results also indicate that the classical correlation of the system is smaller than quantum discord in vacuum reservoir, while it is bigger than quantum discord in squeezed vacuum reservoir. The quantum discord and classical correlation are more robust than quantum concurrence in the two reservoir environments, which indicates that the entanglement actually is easily affected by decoherence and quantum discord has stronger ability to avoid decoherence in squeezed vacuum reservoir.

关键词: quantum correlation, coupled qubits, quantum discord, concurrence

Abstract: In this paper, we investigate the quantum correlation of coupled qubits which are initially in maximally entangled mixed states in squeezed vacuum reservoir. We compare and analyse the effects of squeezed parameters on quantum discord and quantum concurrence. The results show that in squeezed vacuum reservoir, the quantum discord and quantum concurrence perform completely opposite behaviors to the change of squeezed parameters. Quantum discord survives longer with the increase of squeezed amplitude parameter, but entanglement death turns faster on the contrary. The results also indicate that the classical correlation of the system is smaller than quantum discord in vacuum reservoir, while it is bigger than quantum discord in squeezed vacuum reservoir. The quantum discord and classical correlation are more robust than quantum concurrence in the two reservoir environments, which indicates that the entanglement actually is easily affected by decoherence and quantum discord has stronger ability to avoid decoherence in squeezed vacuum reservoir.

Key words: quantum correlation, coupled qubits, quantum discord, concurrence

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)