Topological Insulator in Twisted Transition Metal Dichalcogenide Heterotrilayers

Fuente: arXiv
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Main Authors: He, Hao, Gong, Zhao, Tong, Qing-Jun, Zhai, Dawei, Yao, Wang, An, Xing-Tao
Format: Preprint
Published: 2024
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author He, Hao
Gong, Zhao
Tong, Qing-Jun
Zhai, Dawei
Yao, Wang
An, Xing-Tao
author_facet He, Hao
Gong, Zhao
Tong, Qing-Jun
Zhai, Dawei
Yao, Wang
An, Xing-Tao
contents The quantum spin Hall effect has been predicted in twisted homobilayer transition metal dichalcogenides (TMDs) owing to the layer-pseudospin magnetic field. Recently, experimental observations have also confirmed such topological states of matter. However, the topological electronic properties in multilayer moiré superlattices remain to be further explored. In twisted TMDs heterotrilayers, the realization of moiré potential with various symmetries becomes feasible. Here, we demonstrate that twisted trilayer TMDs can enter a topological insulator phase under the influence of moiré potential with ${C_6}$ symmetry. Specifically, we built two types of trilayer heterostructures, where the low-energy valence band electrons are contributed by the middle layer. In the AA-stacked moiré WS$_2$/WSe$_2$/MoS$_2$ heterotrilayers where only the middle layer is twisted, the maxima of the moiré potential exhibits an approximate ${C_6}$ symmetry. The $C_6$ symmetry effectively compensates for the spatial inversion symmetry breaking in the WSe$_2$ layer, leading to a twist-angle-dependent topological phase transition. Leveraging a Green's function approach, we calculate the local state density of edge states at topological minigaps, confirming their nature as moiré edge states. In the helical twisted AA-stacked moiré MoS$_2$/WSe$_2$/MoS$_2$ heterotrilayers, we observed a mosaic pattern of topological and trivial insulators. The emergence of topological mosaic is attributed to the maxima of the local moiré potential possessing $C_6$ symmetry. The results provide a new way for the experimental realization of topological phases in TMDs heterojunctions.
format Preprint
id arxiv_https___arxiv_org_abs_2410_05197
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological Insulator in Twisted Transition Metal Dichalcogenide Heterotrilayers
He, Hao
Gong, Zhao
Tong, Qing-Jun
Zhai, Dawei
Yao, Wang
An, Xing-Tao
Mesoscale and Nanoscale Physics
The quantum spin Hall effect has been predicted in twisted homobilayer transition metal dichalcogenides (TMDs) owing to the layer-pseudospin magnetic field. Recently, experimental observations have also confirmed such topological states of matter. However, the topological electronic properties in multilayer moiré superlattices remain to be further explored. In twisted TMDs heterotrilayers, the realization of moiré potential with various symmetries becomes feasible. Here, we demonstrate that twisted trilayer TMDs can enter a topological insulator phase under the influence of moiré potential with ${C_6}$ symmetry. Specifically, we built two types of trilayer heterostructures, where the low-energy valence band electrons are contributed by the middle layer. In the AA-stacked moiré WS$_2$/WSe$_2$/MoS$_2$ heterotrilayers where only the middle layer is twisted, the maxima of the moiré potential exhibits an approximate ${C_6}$ symmetry. The $C_6$ symmetry effectively compensates for the spatial inversion symmetry breaking in the WSe$_2$ layer, leading to a twist-angle-dependent topological phase transition. Leveraging a Green's function approach, we calculate the local state density of edge states at topological minigaps, confirming their nature as moiré edge states. In the helical twisted AA-stacked moiré MoS$_2$/WSe$_2$/MoS$_2$ heterotrilayers, we observed a mosaic pattern of topological and trivial insulators. The emergence of topological mosaic is attributed to the maxima of the local moiré potential possessing $C_6$ symmetry. The results provide a new way for the experimental realization of topological phases in TMDs heterojunctions.
title Topological Insulator in Twisted Transition Metal Dichalcogenide Heterotrilayers
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2410.05197