论文标题
测量引起的对称随机量子电路中的拓扑纠缠过渡
Measurement-induced topological entanglement transitions in symmetric random quantum circuits
论文作者
论文摘要
我们研究了一类（1+1）D对称随机量子电路，除了随机统一动力学外，还使用两种相互竞争的测量类型。该电路具有富含对称性保护的拓扑（SPT），微不足道和体积定律纠缠相位的丰富相图，在该阶段中，过渡被隐藏到操作员的期望值，并且只能通过量子轨迹上的纠缠熵访问。在没有统一动力学的情况下，我们发现纯粹的测量诱导的临界点具有纠缠熵的对数缩放率，我们将其精确地映射到经典2D渗透问题的两个副本。我们执行数值模拟，表明这种过渡是一个三级点点，在存在任意稀疏的单一动力学的情况下，与中间的体积定律纠缠相位。我们的结果表明，仅测量值足以诱导关键性和对数纠缠缩放，以及在存在快速但竞争性的测量的情况下，任意稀疏的统一动力学足以稳定体积定律纠缠相位。
We study a class of (1+1)D symmetric random quantum circuits with two competing types of measurements in addition to random unitary dynamics. The circuit exhibits a rich phase diagram involving robust symmetry-protected topological (SPT), trivial, and volume law entangled phases, where the transitions are hidden to expectation values of operators and can only be accessed through the entanglement entropy averaged over quantum trajectories. In the absence of unitary dynamics, we find a purely measurement-induced critical point with logarithmic scaling of the entanglement entropy, which we map exactly to two copies of a classical 2D percolation problem. We perform numerical simulations that indicate this transition is a tricritical point that splits into two critical lines in the presence of arbitrarily sparse unitary dynamics with an intervening volume law entangled phase. Our results show how measurements alone are sufficient to induce criticality and logarithmic entanglement scaling, and how arbitrarily sparse unitary dynamics can be sufficient to stabilize volume law entangled phases in the presence of rapid yet competing measurements.
