Study on Quantum Entanglement Between Mesoscopic Circuit and Environment at Coherent State

作     者：JI Ying-Hua 

作者机构：College of Physics and Communication Electronics Jiangxi Normal University Nanchang 330022 China Key Laboratory of Optoelectronic ＆ Telecommunication of Jiangxi Nanchang 330022 China 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2008年第50卷第10期

页      面：897-902页

核心收录：

学科分类：080805[工学-电工理论与新技术] 080904[工学-电磁场与微波技术] 0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：the Natural Science Foundation of Jiangxi Province of China under Grant No.2007GZW0187 

主　　题：quantum state purity entanglement mesoscopic circuit environment 

摘      要：Taking into account the interaction between electrons and phonons, in the case without-rotating-wave aproximation, we study the entangling property between the mesoscopic circuit and environment at coherent state or equilibrium state. The result indicates that, in long time limit t →∞, the averages of charge and current in the circuit only depend on the average of the system at the initial state when the environment is initially at thermal equilibrimn. However, when the environment is initially at coherent state, the average of charge and current in the circuit is determined by the specific coherent state ensemble. Generally speaking, the entanglement between the circuit and environment will lead to the quantum state purity declining of the circuit, then the circuit emerges decoherent phenomenon, and so a mixed *** appears. Purity changes are related to the initial quantum state of environment and circuit. With the further evolution of time, coherence will be gradually restored, but cannot return to 1.