自旋-玻色系统中纠缠态的量子Fisher信息量演化  

Quantum Fisher information evolution of entangled states in spin-Boson system

作　　者：严凯[1] 谢燕青[1] 黄雨梦 郝翔[1] 

机构地区：[1]苏州科技大学数理学院,江苏省微纳热流技术与能源应用重点实验室,江苏苏州215009

出　　处：《量子电子学报》2018年第1期42-48,共7页Chinese Journal of Quantum Electronics

基　　金：江苏省研究生培养创新工程项目,JGLX15-150,苏州科技大学研究生科研创新项目,SKYCX16-015

摘　　要：基于典型的自旋-玻色模型,研究了具有类欧姆频谱的玻色场环境对量子参数估计精度的影响。原子受外场驱动时,采用二阶含时量子主方程和超算符方法得到了N个独立原子系统量子Fisher信息量的演化结果。计算结果表明:随着纠缠的原子数目增多,量子Fisher信息量增大,量子Fisher信息量的衰减也大大加快。在某些特征时间内,可以获得比标准量子极限更好的测量精度。在频谱幂指数较大的超欧姆玻色环境中,量子纠缠态Fisher信息量的衰减可以在一定程度上被抑制。Effects of Bose field environment with an Ohmic spectrum on estimation accuracy of the quantum parameters are investigated bused on the typical spin-Boson model. Evolution results of quantum Fisher information of N independent atom systems are obtained by using the two order time-dependent quantum master equation and super operator method. Calculation results show that as the number of entangled atoms increases, the quantum Fisher information increases, and the attenuation of quantum Fisher information is also greatly accelerated. Better measurement accuracy than the standard quantum limit can be obtained in some characteristic period. In the super-Ohmic Bosonic environment with a larger spectral power exponent, the attenuation of Fisher information of quantum entangled state can be suppressed to a certain extent.

关 键 词：量子光学 自旋-玻色模型 含时量子主方程 量子Fisher信息量 量子纠缠态 

分 类 号：O413.2[理学—理论物理]