Chin. Phys. B ›› 2013, Vol. 22 ›› Issue (4): 40308-040308.doi: 10.1088/1674-1056/22/4/040308

• GENERAL • 上一篇    下一篇

Non-Markovian dynamics of two non-coupled qubits interacting with two separate reservoirs with different spectral densities

王小云, 丁邦福, 赵鹤平   

  1. College of Physics and Mechanical & Electrical Engineering, Jishou University, Jishou 416000, China
  • 收稿日期:2012-06-08 修回日期:2012-09-16 出版日期:2013-03-01 发布日期:2013-03-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11264011 and 11104113), the Natural Science Foundation of Hunan Province, China (Grant Nos. 09JJ6011 and 11JJ6007), and the Natural Science Foundation of Education Department of Hunan Province, China (Grant No. 11C1057).

Non-Markovian dynamics of two non-coupled qubits interacting with two separate reservoirs with different spectral densities

Wang Xiao-Yun (王小云), Ding Bang-Fu (丁邦福), Zhao He-Ping (赵鹤平)   

  1. College of Physics and Mechanical & Electrical Engineering, Jishou University, Jishou 416000, China
  • Received:2012-06-08 Revised:2012-09-16 Online:2013-03-01 Published:2013-03-01
  • Contact: Wang Xiao-Yun, Ding Bang-Fu E-mail:wxyyun@163.com; dbf1982@126.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11264011 and 11104113), the Natural Science Foundation of Hunan Province, China (Grant Nos. 09JJ6011 and 11JJ6007), and the Natural Science Foundation of Education Department of Hunan Province, China (Grant No. 11C1057).

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摘要： The dynamics of two non-coupled qubits independently interacting with their reservoirs is solved by the time convolutionless projection operator method. We study two-qubit quantum correlation dynamics for two different types of spectral densities, which are a Lorentzian distribution and an Ohmic spectral density with a Lorentzian-Drude cutoff function. For two qubits initially prepared in the initial Bell state, quantum discord can keep longer time and reach larger values in non-Markovian reservoirs for the first spectral distribution or by reducing the cutoff frequency for the second case. For the initial Bell-like state, the dynamic behaviors of quantum discord and entanglement are compared. The results show that a long time of quantum correlation can be obtained by adjusting some parameters in experiment and further confirm that the discord can capture quantum correlation in addition to entanglement.

关键词: Lorentzian and Ohmic spectral densities, the time convolution-less projection operator method, non-Markovian and Markovian regime, quantum discord and entanglement

Abstract: The dynamics of two non-coupled qubits independently interacting with their reservoirs is solved by the time convolutionless projection operator method. We study two-qubit quantum correlation dynamics for two different types of spectral densities, which are a Lorentzian distribution and an Ohmic spectral density with a Lorentzian-Drude cutoff function. For two qubits initially prepared in the initial Bell state, quantum discord can keep longer time and reach larger values in non-Markovian reservoirs for the first spectral distribution or by reducing the cutoff frequency for the second case. For the initial Bell-like state, the dynamic behaviors of quantum discord and entanglement are compared. The results show that a long time of quantum correlation can be obtained by adjusting some parameters in experiment and further confirm that the discord can capture quantum correlation in addition to entanglement.

Key words: Lorentzian and Ohmic spectral densities, the time convolution-less projection operator method, non-Markovian and Markovian regime, quantum discord and entanglement

中图分类号:  (Entanglement measures, witnesses, and other characterizations)

  • 03.67.Mn
03.65.Yz (Decoherence; open systems; quantum statistical methods) 42.50.Lc (Quantum fluctuations, quantum noise, and quantum jumps)