Quantum systems that undergo quantum phase transitions exhibit divergent susceptibility and can be exploited as probes to estimate physical parameters. We generalize the dynamic framework for criticality-enhanced quantum sensing by the quantum Rabi model (QRM) to its anisotropic counterpart and derive the correspondingly analytical expressions for the quantum Fisher information (QFI). We find that the contributions of the rotating-wave and counterrotating-wave interaction terms are symmetric at the limit of the infinite ratio of qubit frequency to field frequency, with the QFI reaching a maximum for the isotropic quantum Rabi model. At finite frequency scaling, we analytically derive the inverted variance of higher-order correction and find that it is more affected by the rotating-wave coupling than by the counterrotating-wave coupling.

翻译：经历量子相变的量子系统会表现出发散性磁化率，可作为探针用于物理参数估计。我们将临界增强量子传感的动态框架从量子拉比模型推广到其各向异性对应模型，并推导了对应的量子Fisher信息的解析表达式。研究发现，在量子比特频率与场频率之比趋于无穷的极限条件下，旋转波项与反旋转波项的贡献呈对称性，且各向同性量子拉比模型中的量子Fisher信息达到最大值。在有限频率标度下，我们解析推导了高阶修正的反向方差，发现旋转波耦合对其影响程度大于反旋转波耦合。