论文标题
狂犬病模型以有限频率比的量子关键性
Quantum criticality of the Rabi-Stark model at finite frequency ratios
论文作者
论文摘要
在本文中，我们根据能隙，顺序参数以及保真度以有限的比率分析了狂犬病模型的量子关键性，如果鲜明的耦合强度与空腔频率相同。关键指数是通过分析得出的。能量差距和长度临界指数与量子兔模型和DICKE模型中的能量差距不同。还进行了订单参数的有限尺寸缩放分析和保真度易感性。展示了通用缩放行为，然后可以提取几个有限尺寸的指数。此外，还可以根据骨器希尔伯特空间截断数量建立普遍的临界行为，并发现相应的临界缩放指数。有趣的是，在狂犬病模型和量子兔模型中，临界相关长度指数以及等效的长度尺度在不同的有效长度尺度方面有所不同，这表明它们属于不同的普遍性类别。相比之下，二阶量子相变在有限的频率比下以有限的频率比进行了令人信服的证实，它仅在原始量子狂犬模型中以无限频率比出现，而无需鲜明的耦合。
In this paper, we analyze the quantum criticality of the Rabi-Stark model at finite ratios of the qubit and cavity frequencies in terms of the energy gap, the order parameter, as well as the fidelity, if the Stark coupling strength is the same as the cavity frequency. The critical exponents are derived analytically. The energy gap and the length critical exponents are different from those in the quantum Rabi model and the Dicke model. The finite size scaling analysis for the order parameter and the fidelity susceptibility is also performed. The universal scaling behaviors are demonstrated and several finite size exponents can be then extracted. Furthermore, universal critical behavior can be also established in terms of the bosonic Hilbert space truncation number, and the corresponding critical scaling exponents are found. Interestingly, the critical correlation length exponents in terms of the photonic truncation number as well as the equivalently effective length scales are different in the Rabi-Stark model and the quantum Rabi model, suggesting they belong to different universality classes. The second-order quantum phase transition is convincingly corroborated in the Rabi-Stark model at finite frequency ratios, by contrast, it only emerges at the infinite frequency ratio in the original quantum Rabi model without the Stark coupling.
