Incommensurate many-body localization in the presence of long-range hopping and single-particle mobility edge

作者：Ke Huang, DinhDuy Vu, Xiao Li, S. Das Sarma · 发表于：Physical review. B./Physical review. B · 年份：2023 · DOI：10.1103/physrevb.107.035129 · 被引用次数：19 · 研究领域：Quantum many-body systems、Physics of Superconductivity and Magnetism、Quantum and electron transport phenomena

We study many-body localization (MBL) in the quasiperiodic ${t}_{1}\text{\ensuremath{-}}{t}_{2}$ model, focusing on the role of next-nearest-neighbor (NNN) hopping ${t}_{2}$, which introduces a single-particle mobility edge. The calculated phase diagram can be divided into three distinct regimes, depending on the strength of the short-range interaction $U$. For weak interactions ($U\ensuremath{\ll}{t}_{1}$), this model is always nonthermal. For intermediate interactions ($U\ensuremath{\sim}{t}_{1}$), the thermal-MBL phase transition in this model is qualitatively the same as that of the Aubry-Andre (AA) model, which is consistent with existing experimental observations. For strong interactions $(U\ensuremath{\gg}{t}_{1})$, the NNN hopping produces qualitatively new physics because it breaks down the Hilbert space fragmentation present in the AA model. The NNN hopping is thus irrelevant when the interaction is intermediate but relevant for strong interactions.