Xie Ming, Hafezi Mohammad, Das Sarma Sankar
Condensed Matter Theory Center, Department of Physics, <a href="https://ror.org/047s2c258">University of Maryland</a>, College Park, Maryland 20742, USA.
<a href="https://ror.org/04xz38214">Joint Quantum Institute</a>, Department of Physics, <a href="https://ror.org/047s2c258">University of Maryland</a>, College Park, Maryland 20742, USA.
Phys Rev Lett. 2024 Sep 27;133(13):136403. doi: 10.1103/PhysRevLett.133.136403.
Moiré superlattices based on two-dimensional transition metal dichalcogenides (TMDs) have emerged as a highly versatile and fruitful platform for exploring correlated topological electronic phases. One of the most remarkable examples is the recently discovered fractional quantum anomalous Hall effect (FQAHE) under zero magnetic field. Here, we propose a minimal structure that hosts long-lived excitons-a ubiquitous bosonic excitation in TMD semiconductors-with narrow topological bosonic bands. The nontrivial exciton topology originates from hybridization of moiré interlayer excitons and is tunable by controlling twist angle and electric field. At small twist angle, the lowest exciton bands are isolated from higher energy bands and provide a solid-state realization of the bosonic Kane-Mele model with topological flatbands, which could potentially support the bosonic version of FQAHE.
基于二维过渡金属二硫族化合物（TMDs）的莫尔超晶格已成为探索相关拓扑电子相的一个高度通用且富有成果的平台。最显著的例子之一是最近在零磁场下发现的分数量子反常霍尔效应（FQAHE）。在此，我们提出一种具有窄拓扑玻色子能带的最小结构，该结构能容纳长寿命激子——TMD半导体中普遍存在的玻色子激发。非平凡的激子拓扑源于莫尔层间激子的杂化，并且可以通过控制扭转角和电场来调节。在小扭转角下，最低激子能带与高能带隔离，并提供了具有拓扑平带的玻色子凯恩 - 梅勒模型的固态实现，这可能潜在地支持FQAHE的玻色子版本。
