Wang Qian, Pérez-Bernal Francisco
Department of Physics, Zhejiang Normal University, Jinhua 321004, China and CAMTP-Center for Applied Mathematics and Theoretical Physics, University of Maribor, Mladinska 3, SI-2000 Maribor, Slovenia.
Departamento de Ciencias Integradas y Centro de Estudios Avanzados en Física, Matemáticas y Computación, Universidad de Huelva, Huelva 21071, Spain and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, Granada 18071, Spain.
Phys Rev E. 2021 Mar;103(3-1):032109. doi: 10.1103/PhysRevE.103.032109.
Using the diagonal entropy, we analyze the dynamical signatures of the Lipkin-Meshkov-Glick model excited-state quantum phase transition (ESQPT). We first show that the time evolution of the diagonal entropy behaves as an efficient indicator of the presence of an ESQPT. We also compute the probability distribution of the diagonal entropy values over a certain time interval and we find that the resulting distribution provides a clear distinction between the different phases of ESQPT. Moreover, we observe that the probability distribution of the diagonal entropy at the ESQPT critical point has a universal form, well described by a beta distribution, and that a reliable detection of the ESQPT can be obtained from the diagonal entropy central moments.
利用对角熵，我们分析了Lipkin-Meshkov-Glick模型激发态量子相变（ESQPT）的动力学特征。我们首先表明，对角熵的时间演化可作为ESQPT存在的有效指标。我们还计算了在特定时间间隔内对角熵值的概率分布，发现所得分布能清晰区分ESQPT的不同相。此外，我们观察到ESQPT临界点处对角熵的概率分布具有一种通用形式，可用贝塔分布很好地描述，并且从对角熵中心矩可获得对ESQPT的可靠检测。
