含互感耦合的超导磁通量子比特消相干的研究  

Investigation on Decoherence of Superconducting Flux Qubit with Mutual Inductance Coupling

作　　者：肖珊[1] 王丽华[2] 

机构地区：[1]江西医学院上饶分院 [2]江西科技师范学院

出　　处：《江西科学》2008年第6期891-895,共5页Jiangxi Science

摘　　要：在Born-Markov近似下,根据Bloch-Redfield方程,给出了一种计算超导量子比特能量弛豫时T1与消相干时间T2的方法。在此基础上,研究了一个含互感耦合的超导磁通量子比特的消相干现象,并给出了该超导量子比特能量弛豫时间T1与消相干时间T2。结果表明:对于研究的磁通量子比特,在其他条件不变时且环境热库等效为一个纯电阻时,则去相位时间T,由高能级|j〉向低能级|i〉的能量弛豫时间T1和量子系统的消相干时间T2都与耗散成正比。In Born-Markov approximation, according to Bloch-Redfield equation, the method to calculate the relaxation time T1 and decoherence time T2 of superconducting qubit is given. Based on this, the decoherence phenomenon of superconducting flux qubit with mutual inductance coupling is investigated. The energy relaxation time T1 and decoherence time T2 of this superconducting qubit is also obtained. The results show that for the flux qubit under investigation, the dephasing time Tφ, the energy relaxation time T1 from high level ｜j〉 to low level ｜i〉 ,and the decoherence time T2 of the quantum system are all proportional to dissipation when other conditions are invariant and the environment thermal bath is equivalent to a pure resistance.

关 键 词：磁通量子比特 消相干 耦合 Born—Markov近似 

分 类 号：O413[理学—理论物理]