论文标题
超阶相关性和浮力动力学量子相变
Out-of-time-order correlations and Floquet dynamical quantum phase transition
论文作者
论文摘要
超阶相关器（OTOC）逐渐在不同的物理领域，尤其是在非平衡量子多体系统中起重要作用。在本文中，我们表明可以使用OTOC来探究Floquet动力学量子相变（FDQPTS）。我们研究了两个准确可溶解的浮子自旋模型的OTOC，即：Floquet XY链和同步Floquet XY模型。我们表明，驱动频率范围的边界在该频率范围内显示了Floquet XY模型在该频率范围内显示FDQPT，这是通过无限温度时间的全局最小值的信号平均。此外，我们的结果表明，长期以来，OTOCS衰减代数，为此，FDQPT区域中的衰减指数与系统未显示FDQPT的区域不同。另外，对于同步的Floquet XY模型，FDQPT在任何驱动频率下发生，具体取决于无限或有限温度下的初始条件，每当系统显示FDQPT时，OTOC的假想部分就会为零。
Out-of-time-order correlators (OTOCs) progressively play an important role in different fields of physics, particularly in the non-equilibrium quantum many-body systems. In this paper, we show that OTOCs can be used to prob the Floquet dynamical quantum phase transitions (FDQPTs). We investigate the OTOCs of two exactly solvable Floquet spin models, namely: Floquet XY chain and synchronized Floquet XY model. We show that the border of driven frequency range, over which the Floquet XY model shows FDQPT, signals by the global minimum of the infinite-temperature time averaged OTOC. Moreover, our results manifest that OTOCs decay algebraically in the long time, for which the decay exponent in the FDQPT region is different from that of in the region where the system does not show FDQPTs. In addition, for the synchronized Floquet XY model, where FDQPT occurs at any driven frequency depending on the initial condition at infinite or finite temperature, the imaginary part of the OTOCs become zero whenever the system shows FDQPT.
