论文标题
部分可观测时空混沌系统的无模型预测
Entanglement evolution after a global quench across a conformal defect
论文作者
论文摘要
我们研究了具有局部杂质的一维量子系统中全球淬火后纠缠的演变。对于由保形场理论描述的系统，两个区域之间被缺陷隔开的区域之间的纠缠熵在及时线性增长。引入边界扭转场的概念，我们展示了这种生长的斜率如何与缺陷存在下在地面熵研究中出现的有效中心电荷有关。另一方面，我们还考虑了具有保形缺陷的自由屈服链中淬火的特殊晶格实现。从凹陷的初始状态开始，我们通过准粒子Ansatz获得斜率，并观察到野外理论和晶格结果之间的差异很小，即使在消失的缝隙的极限下，它们仍然存在。
We study the evolution of entanglement after a global quench in a one-dimensional quantum system with a localized impurity. For systems described by a conformal field theory, the entanglement entropy between the two regions separated by the defect grows linearly in time. Introducing the notion of boundary twist fields, we show how the slope of this growth can be related to the effective central charge that emerges in the study of ground-state entropy in the presence of the defect. On the other hand, we also consider a particular lattice realization of the quench in a free-fermion chain with a conformal defect. Starting from a gapped initial state, we obtain the slope via a quasiparticle ansatz and observe small discrepancies between the field theory and lattice results, which persist even in the limit of a vanishing gap.
