J4 ›› 2012, Vol. 29 ›› Issue (4): 441-447.

• Quantum Optics • Previous Articles     Next Articles

Influence of Stark shift on entropy and entanglement in J-C model with mixed states

HU Yaohua   

  1. College of Physics and Electronic Information , Luoyang Normal College, Luoyang 471022, China
  • Received:2012-02-07 Revised:2012-03-12 Published:2012-07-28 Online:2012-07-01

Abstract:

A two-level atom coupling with a single-mode thermal ?eld through two-photon processes is considered. It is studied that the reduced entropy change of the atom and the ?eld by using quantum reduced entropy, and entanglement between the atom and field measured by using Concurrence. By mean of numerical computation method, The e?ect of the Stark shift and the mean photon number in the J-C model with mixed states on the reduced entropy change and entanglement is investigated. The results show that reduced entropy changes of the atom and the ?eld decrease under the influence of the Stark shift. When the initial parameters are suitable, the complete exchange between the atomic and field reduced entropy occurs. In addition, the minimum values of the entanglement raise in the presence of the Stark shift, which means that the atom is no longer disentangled from the field.

Key words: quantum optics, entanglement, concurrence, reduced entropy, Stark shift, Jaynes-Cummings model

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