论文标题
部分可观测时空混沌系统的无模型预测
Entanglement entropy distinguishes PT-symmetry and topological phases in a class of non-unitary quantum walks
论文作者
论文摘要
我们计算在非自由量子步行中硬币和沃克自由度之间的混合纠缠熵。该模型具有关节奇偶校验和时间反向对称性或PT对称性，并在其特征状态不间断时支持拓扑阶段。长时间的渐近分析表明，即使存在增益和损失机制，量子行走也可以在不间断的对称阶段无限期地维持混合纠缠。但是，当减肥强度太大时，模型的PT对称性自发折断，纠缠消失。因此，纠缠熵是在此非自然动力学系统中构建PT对称和拓扑相图的有效参数。
We calculate the hybrid entanglement entropy between coin and walker degrees of freedom in a non-unitary quantum walk. The model possesses a joint parity and time-reversal symmetry or PT-symmetry and supports topological phases when this symmetry is unbroken by its eigenstates. An asymptotic analysis at long times reveals that the quantum walk can indefinitely sustain hybrid entanglement in the unbroken symmetry phase even when gain and loss mechanisms are present. However, when the gain-loss strength is too large, the PT-symmetry of the model is spontaneously broken and entanglement vanishes. The entanglement entropy is therefore an effective and robust parameter for constructing PT-symmetry and topological phase diagrams in this non-unitary dynamical system.
