标题： 从交叉帽态出发的纠缠淬火动力学 显示英文标题

标题： Quench dynamics of entanglement from crosscap states

摘要： 在来自具有短程关联状态的淬火后，纠缠的线性增长是多体动力学的一个普遍特征。它已被证明出现在可积和混沌系统中，这些系统经历哈密顿、弗洛凯或电路动力学，并且也在实验中被观察到。从长程关联态中产生的纠缠动力学研究得远少于前者，尽管现代量子模拟实验同样可行。在本工作中，我们研究了初始状态的双部分纠缠熵和互信息的动力学，这些初始状态具有长程纠缠，并且在有限且周期性系统的对径点之间存在关联。从这些交叉帽态出发，我们研究了砖墙量子电路和哈密顿动力学，并发现根据动力学类型以及系统是否可积或混沌，表现出不同的行为模式。具体来说，我们研究了双单位量子电路和随机单位量子电路，以及自由和相互作用费米子哈密顿量。对于可积系统，我们发现经过一段时间延迟后，纠缠会随时间线性减少，然后出现一系列复兴；而相比之下，混沌系统表现出恒定的纠缠熵。另一方面，两种系统都会立即随时间线性减少互信息。在混沌系统中，这随后消失，而在可积系统中则出现一系列复兴。我们展示了纠缠动力学的准粒子和膜图像如何修改以描述这种行为，并明确推导了自由费米子模型中的准粒子图像，然后将其扩展到所有可积系统。 显示英文摘要

摘要： The linear growth of entanglement after a quench from a state with short-range correlations is a universal feature of many body dynamics. It has been shown to occur in integrable and chaotic systems undergoing either Hamiltonian, Floquet or circuit dynamics and has also been observed in experiments. The entanglement dynamics emerging from long-range correlated states is far less studied, although no less viable using modern quantum simulation experiments. In this work, we investigate the dynamics of the bipartite entanglement entropy and mutual information from initial states which have long-range entanglement with correlation between antipodal points of a finite and periodic system. Starting from these crosscap states, we study both brickwork quantum circuits and Hamiltonian dynamics and find distinct patterns of behaviour depending on the type of dynamics and whether the system is integrable or chaotic. Specifically, we study both dual unitary and random unitary quantum circuits as well as free and interacting fermion Hamiltonians. For integrable systems, we find that after a time delay the entanglement experiences a linear in time decrease followed by a series of revivals, while, in contrast, chaotic systems exhibit constant entanglement entropy. On the other hand, both types of systems experience an immediate linear decrease of the mutual information in time. In chaotic systems this then vanishes, whereas integrable systems instead experience a series of revivals. We show how the quasiparticle and membrane pictures of entanglement dynamics can be modified to describe this behaviour, and derive explicitly the quasiparticle picture in the case of free fermion models which we then extend to all integrable systems.