论文标题
量子中的激发状态量子相变的签名许多身体系统：相空间分析
Signatures of excited state quantum phase transitions in quantum many body systems: Phase space analysis
论文作者
论文摘要
使用HUSIMI函数，我们研究了Lipkin和耦合顶部模型中激发态量子相变（ESQPTS）的相空间特征。我们表明，Husimi函数的时间演化在ESQPT的不同阶段和ESQPT的存在之间表现出不同的行为，这是由Husimi函数的特定动力学信号。我们还评估了长期以来的HUSIMI函数及其相关的边缘分布，并讨论如何从其性质中识别ESQPT的签名。此外，通过利用长期平均Husimi函数的第二刻和熵的熵，我们估计了ESQPTS的临界点，证明了与分析结果良好的一致性。因此，我们提供了进一步的证据表明，相空间方法是研究相变研究的有价值工具，并且还打开了一种检测ESQPTS的新方法。
Using the Husimi function, we investigate the phase space signatures of the excited state quantum phase transitions (ESQPTs) in the Lipkin and coupled top models. We show that the time evolution of the Husimi function exhibits distinct behaviors between the different phases of an ESQPT and the presence of an ESQPT is signaled by the particular dynamics of the Husimi function. We also evaluate the long time averaged Husimi function and its associated marginal distributions, and discuss how to identify the signatures of ESQPT from their properties. Moreover, by exploiting the second moment and Wherl entropy of the long-time averaged Husimi function, we estimate the critical points of ESQPTs, demonstrating a good agreement with the analytical results. We thus provide further evidence that the phase space methods is a valuable tool for the studies of phase transitions and also open a new way to detect ESQPTs.
