Influence of Atomic Relaxations on the Moire Flat Band Wave Functions in Antiparallel Twisted Bilayer WS2

被引：5

作者：

Molino, Laurent ^{[1
]}

Aggarwal, Leena ^{[1
]}

Maity, Indrajit ^{[2
]}

Plumadore, Ryan ^{[1
]}

Lischner, Johannes ^{[2
,3
]}

Luican-Mayer, Adina ^{[1
]}

机构：

[1] Univ Ottawa, Dept Phys, Ottawa, ON K1N 6X3, Canada

[2] Imperial Coll London, Dept Mat, London SW7 2AZ, England

[3] Thomas Young Ctr Theory & Simulat Mat, London SW7 2BP, England

来源：

NANO LETTERS | 2023年 / 23卷 / 24期

基金：

英国工程与自然科学研究理事会; 加拿大自然科学与工程研究理事会; 欧盟地平线“2020”;

关键词：

moire pattern; scanning tunnelingmicroscopy; density functional theory; transitionmetal dichalcogenides; MOS2/WS2;

D O I：

10.1021/acs.nanolett.3c03735

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Twisting bilayers of transition metal dichalcogenides gives rise to a moir & eacute; potential resulting in flat bands with localized wave functions and enhanced correlation effects. In this work, scanning tunneling microscopy is used to image a WS2 bilayer twisted approximately 3 degrees off the antiparallel alignment. Scanning tunneling spectroscopy reveals localized states in the vicinity of the valence band onset, which is observed to occur first in regions with S-on-S Bernal stacking. In contrast, density functional theory calculations on twisted bilayers that have been relaxed in vacuum predict the highest-lying flat valence band to be localized in regions of AA ' stacking. However, agreement with experiment is recovered when the calculations are performed on bilayers in which the atomic displacements from the unrelaxed positions have been reduced, reflecting the influence of the substrate and finite temperature. This demonstrates the delicate interplay of atomic relaxations and the electronic structure of twisted bilayer materials.

引用

页码：11778 / 11784

页数：7

共 42 条

[1] Interaction effects and superconductivity signatures in twisted double-bilayer WSe2 [J].