论文标题
动力学转变的机理：复杂的时间生存幅度
Mechanism of dynamical phase transitions: The complex-time survival amplitude
论文作者
论文摘要
动态相变是通过在某些关键时期的非平衡时间发展状态的生存概率的非分析性来定义的。它们来自相应生存幅度的零。通过将时间变量扩展到复杂域，我们制定了复杂的时间存活幅度。在时间轴附近的该数量的复杂零在无限尺寸的极限中对应于生存概率突然消失的非分析点。我们的结果在数字上被示例在完全连接的横向场模型中，该模型显示了由激发状态量子相变界定的对称性折叠相。当提出了平衡方案变化的特征时，对复杂时间存活幅度的行为进行了详细研究。激发状态量子相变的影响也被置于上下文中。
Dynamical phase transitions are defined through non-analyticities of the survival probability of an out-of-equilibrium time-evolving state at certain critical times. They ensue from zeros of the corresponding survival amplitude. By extending the time variable onto the complex domain, we formulate the complex-time survival amplitude. The complex zeros of this quantity near the time axis correspond, in the infinite-size limit, to non-analytical points where the survival probability abruptly vanishes. Our results are numerically exemplified in the fully-connected transverse-field Ising model, which displays a symmetry-broken phase delimited by an excited-state quantum phase transition. A detailed study of the behavior of the complex-time survival amplitude when the characteristics of the out-of-equilibrium protocol changes is presented. The influence of the excited-state quantum phase transition is also put into context.
