论文标题
在随机电路中吸收状态相变的纠缠
Controlling entanglement at absorbing state phase transitions in random circuits
论文作者
论文摘要
散布重复测量的多体统一动力学表现出以测量引起的相变为标志的丰富现象学。我们采用将动力学转向吸收状态的反馈控制操作，我们研究了吸收状态相变的纠缠熵行为。对于短距离控制操作，我们观察到具有纠缠熵不同的范围尺度不同的阶段之间的过渡。相比之下，该系统进行了长期反馈操作之间的体积法和区域律阶段之间的过渡。纠缠熵的波动和吸收状态过渡的顺序参数完全耦合，以充分强烈纠缠反馈操作。在这种情况下，纠缠熵继承了吸收状态过渡的普遍动态。但是，这并不是任意控制操作的情况，而且两个过渡通常是不同的。我们通过引入基于具有经典标志标签的稳定器电路的框架来定量支持我们的结果。我们的结果为测量引起的相变的可观察性问题提供了新的启示。
Many-body unitary dynamics interspersed with repeated measurements display a rich phenomenology hallmarked by measurement-induced phase transitions. Employing feedback-control operations that steer the dynamics toward an absorbing state, we study the entanglement entropy behavior at the absorbing state phase transition. For short-range control operations, we observe a transition between phases with distinct sub-extensive scalings of entanglement entropy. In contrast, the system undergoes a transition between volume-law and area-law phases for long-range feedback operations. The fluctuations of entanglement entropy and of the order parameter of the absorbing state transition are fully coupled for sufficiently strongly entangling feedback operations. In that case, entanglement entropy inherits the universal dynamics of the absorbing state transition. This is, however, not the case for arbitrary control operations, and the two transitions are generally distinct. We quantitatively support our results by introducing a framework based on stabilizer circuits with classical flag labels. Our results shed new light on the problem of observability of measurement-induced phase transitions.
