论文标题
无序相互作用系统中流动边缘的稳定性
Stability of mobility edges in disordered interacting systems
论文作者
论文摘要
多体定位提供了一种避免在孤立相互作用量子系统中进行热化的机制。当所谓的多体迁移率边缘分离频谱的局部和离域部分时，当多体谱中的所有特征状态都变得本地化或部分时，热量的分解可能是完整的。以前，de Roeck \ textit {等} [arxiv：1506.01505]提出了能量密度的多体迁移率边缘的不稳定性。所谓的“气泡”的局部ergodic区域会引起整个系统的共鸣，从而导致离域。为了研究这种不稳定性机制，在这项工作中，我们设计了一个模型，具有\ emph {粒子密度}中的多体迁移率边缘}：小粒子密度的状态是局部的，同时增加颗粒的密度会导致定位。使用基质产物状态的数值模拟，我们证明了MBL在大型稀释系统中用于实验相关时间表的小气泡的稳定性。此外，我们证明了气泡扩展比导致谐音隧道的过程的过程，这表明观察到的多体迁移率边缘的稳定性背后可能是一种可能的机制。我们通过提出实验来探测Bose-Hubbard模型中的粒子密度迁移率边缘的结论。
Many-body localization provides a mechanism to avoid thermalization in isolated interacting quantum systems. The breakdown of thermalization may be complete, when all eigenstates in the many-body spectrum become localized, or partial, when the so-called many-body mobility edge separates localized and delocalized parts of the spectrum. Previously, De Roeck \textit{et al.}[arXiv:1506.01505] suggested a possible instability of the many-body mobility edge in energy density. The local ergodic regions -- so called "bubbles" -- resonantly spread throughout the system, leading to delocalization. In order to study such instability mechanism, in this work we design a model featuring many-body mobility edge in \emph{particle density}: the states at small particle density are localized, while increasing the density of particles leads to delocalization. Using numerical simulations with matrix product states we demonstrate the stability of MBL with respect to small bubbles in large dilute systems for experimentally relevant timescales. In addition, we demonstrate that processes where the bubble spreads are favored over processes that lead to resonant tunneling, suggesting a possible mechanism behind the observed stability of many-body mobility edge. We conclude by proposing experiments to probe particle density mobility edge in Bose-Hubbard model.
