中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3595-3600.doi: 10.1088/1009-1963/16/12/007

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Entanglement in a generalized Jaynes--Cummings model

张国锋, 刘 佳   

  1. Department of Physics, School of Sciences, Beijing University of Aeronauticsand Astronautics, Beijing 100083, China
  • 出版日期:2007-12-20 发布日期:2007-12-20
  • 基金资助:
    Project supported by the National Nature Science Foundation of China (Grant No 10604053).

Entanglement in a generalized Jaynes--Cummings model

Zhang Guo-Feng(张国锋)† and Liu Jia(刘佳)   

  1. Department of Physics, School of Sciences, Beijing University of Aeronauticsand Astronautics, Beijing 100083, China
  • Online:2007-12-20 Published:2007-12-20
  • Supported by:
    Project supported by the National Nature Science Foundation of China (Grant No 10604053).

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摘要： We investigate the pairwise entanglement and global entanglement in a generalized Jaynes--Cummings model, which can be used to realize Greenberger--Horne--Zeilinger (GHZ) entangled state (Zheng S B 2001 {\it Phys. Rev. Lett.} {\bf 87} 230404). Our results show that the W-type entangled states cannot be generated based on the model. The dependences of entanglement on Rabi frequency $\lambda$ and dipole--dipole coupling strength ${\it \Omega}$ are given. It is found that there exists the quantum phase transition when $\lambda={\it \Omega}$. For typical experimental data, the critical temperature for pairwise entanglement is on the order of $10^{-6}$\,K. Based on these results, two strategies that overcome decoherence are proposed.

关键词: thermal entanglement, dipole--dipole coupling strength, decoherence

Abstract: We investigate the pairwise entanglement and global entanglement in a generalized Jaynes--Cummings model, which can be used to realize Greenberger--Horne--Zeilinger (GHZ) entangled state (Zheng S B 2001 Phys. Rev. Lett. 87 230404). Our results show that the W-type entangled states cannot be generated based on the model. The dependences of entanglement on Rabi frequency $\lambda$ and dipole--dipole coupling strength ${\it \Omega}$ are given. It is found that there exists the quantum phase transition when $\lambda={\it \Omega}$. For typical experimental data, the critical temperature for pairwise entanglement is on the order of $10^{-6}$ K. Based on these results, two strategies that overcome decoherence are proposed.

Key words: thermal entanglement, dipole--dipole coupling strength, decoherence

中图分类号:  (Quantum state engineering and measurements)

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