Partial entropy change and entanglement in the mixed state for a Jaynes－Cummingsmodel with Kerr medium

• Published in: Chinese physics B no. 2; pp. 303 - 311
• Main Author: 张玉青 谭磊 朱中华 熊祖周 刘利伟
• Format: Journal Article
• Language: English
• Published: 2010
• Subjects: 克尔介质; 克尔非线性; 动力学方法; 局部熵; 混合状态; 熵变化; 非线性强度
• ISSN: 1674-1056; 2058-3834

By using the algebraic dynamical approach, an atom--field bipartite system in mixed state is employed to investigate the partial entropy change and the entanglement in a cavity filled with Kerr medium. The effects of different nonlinear intensities are studied. One can find that the Kerr nonlinearity can reduce the fluctuation amplitudes of the partial entropy changes and the entanglement of the two subsystems, and also influence their periodic evolution. Meanwhile, increasing the Kerr nonlinear strength can convert the anti-correlated behaviour of the partial entropy change to the positively correlated behaviour. Furthermore, the entanglement greatly depends on the temperature. When the temperature or the nonlinear intensity increases to a certain value, the entanglement can be suppressed greatly.