Nonequilibrium dynamics in isolated quantum many-body systems displays a number of intriguing features, such as many-body localization (MBL) and prethermalization. Here we investigate a simple ladder system with disorder, in which various distinct dynamical features coexist and interplay. By exact diagonalization, we demonstrate that the system exhibits the signatures of an MBL-ergodic-MBL reentrant transition, metastability, and disorder-free MBL. We give an account of these properties by introducing a quasiparticle picture and interpreting the quasivacuum energy fluctuation as an effective disorder on the quasi-particle dynamics. It is speculated that the weak perturbation behavior is a finite-size effect, but its relaxation timescale increases with the system size.

中文翻译：

---

微弱摄动的多体定位和亚稳定性的特征

孤立的量子多体系统中的非平衡动力学表现出许多有趣的特征，例如多体定位（MBL）和预热。在这里，我们研究了一个带有障碍的简单梯子系统，其中各种不同的动力学特征共存并相互作用。通过精确的对角线化，我们证明了该系统具有MBL遍历MBL折返过渡，亚稳性和无障碍MBL的特征。我们通过引入准粒子图片并解释准量子能量波动作为准粒子动力学的有效障碍来解释这些属性。据推测，弱摄动行为是有限大小的效应，但是其弛豫时间尺度随系统大小而增加。