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arXiv 2104.01635cond-mat.dis-nncond-mat.str-el
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拓扑与多体局域化

Topology and many-body localization

R. N. Bhatt, Akshay Krishna

摘要:

本文讨论了量子霍尔(单朗道能级)体系中二维电子系统的局域化问题。在简要总结了非相互作用情况下安德森局域化问题的研究成果后,我们利用数值精确对角化方法和本征值间距统计方法研究了电子-电子相互作用下的无序诱导多体局域化(MBL)问题.我们提供的证据表明,MBL是无法实现在一个单一的朗道水平与短程(白噪声)的热力学极限的障碍。然后,我们研究了拓扑和本地化的相互作用,通过对比的行为,从一个单一的朗道水平在两个模型中产生的拓扑和非拓扑子带-(i)一对非常平坦的Hofstadter带与一个最佳选择的周期性的潜力,和(ii)朗道水平与分裂的非拓扑杂质带。这两个模型提供了令人信服的证据,强大的影响拓扑结构的可行性多体局域化,以及从一个非平衡态与电荷不平衡的慢动力学。

英文摘要:

We discuss the problem of localization in two dimensional electron systems in the quantum Hall (single Landau level) regime. After briefly summarizing the well-studied problem of Anderson localization in the non-interacting case, we concentrate on the problem of disorder induced many-body localization (MBL) in the presence of electron-electron interactions using numerical exact diagonalization and eigenvalue spacing statistics as a function of system size. We provide evidence showing that MBL is not attainable in a single Landau level with short range (white noise) disorder in the thermodynamic limit. We then study the interplay of topology and localization, by contrasting the behavior of topological and nontopological subbands arising from a single Landau level in two models - (i) a pair of extremely flat Hofstadter bands with an optimally chosen periodic potential, and (ii) a Landau level with a split-off nontopological impurity band. Both models provide convincing evidence for the strong effect of topology on the feasibility of many-body localization as well as slow dynamics starting from a nonequilibrium state with charge imbalance.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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