论文标题
动态量子相变的解剖结构
Anatomy of Dynamical Quantum Phase Transitions
论文作者
论文摘要
量子多体模型的全局淬火会导致直接连接到Landau Order参数（OP）的零的周期性动力学量子相变（DQPTS）。相关的动力学已被认为与两级系统的Rabi振荡特征非常相似。在这里，我们解决了这种DQPT行为是否仅仅是有效的两级系统限制的表现，还是作为更复杂的动态的一部分出现的问题。我们专注于量子多体疤痕作为有用的玩具模型，使我们能够自然研究原本混乱的系统中的状态转移。我们发现，DQPT表示对退化初始状态歧管中波函数的主要贡献的变化，仅在均匀退化歧管的中点发生的特殊情况下与OP零的直接关系。我们的工作概括了先前的结果，并揭示了一般而言，定期DQPTS从根本上构成了复杂的多体动力学，而不是两层系统。
Global quenches of quantum many-body models can give rise to periodic dynamical quantum phase transitions (DQPTs) directly connected to the zeros of a Landau order parameter (OP). The associated dynamics has been argued to bear close resemblance to Rabi oscillations characteristic of two-level systems. Here, we address the question of whether this DQPT behavior is merely a manifestation of the limit of an effective two-level system or if it can arise as part of a more complex dynamics. We focus on quantum many-body scarring as a useful toy model allowing us to naturally study state transfer in an otherwise chaotic system. We find that a DQPT signals a change in the dominant contribution to the wave function in the degenerate initial-state manifold, with a direct relation to an OP zero only in the special case of occurring at the midpoint of an evenly degenerate manifold. Our work generalizes previous results and reveals that, in general, periodic DQPTs comprise complex many-body dynamics fundamentally beyond that of two-level systems.
