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 based 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.