Electronic localization in twisted bilayer MoS$_2$ with small rotation angle

TL;DR

This study models electronic states in twisted bilayer MoS₂ across all rotation angles, revealing the emergence of flatbands at small angles, which could influence future semiconductor applications.

Contribution

A revised Slater-Koster tight-binding model enabling systematic analysis of electronic localization in twisted bilayer MoS₂ for all rotation angles.

Findings

Isolated low-energy bands appear at angles less than 5-6 degrees.

Flatbands with zero average velocity occur at angles below 2 degrees.

Model provides a reliable tool for studying moiré-induced electronic states.

Abstract

Moir\'e patterns are known to confine electronic states in transition metal dichalcogenide bilayers, thus generalizing the notion of magic angles discovered in twisted bilayer graphene to semiconductors. Here, we present a revised Slater-Koster tight-binding model that facilitates the first reliable and systematic studies of such states in twisted bilayer MoS$_2$ for the whole range of rotation angles $\theta$. We show that isolated bands appear at low energy for $\theta \lesssim 5 - 6^\circ$. Moreover, these bands become "flatbands", characterized by a vanishing average velocity, for the smallest angles $\theta \lesssim 2^\circ$.