Trapping Interlayer Excitons in van der Waals Heterostructures by Potential Arrays

TL;DR

This paper presents a model for trapping interlayer excitons in van der Waals heterostructures, highlighting the role of dipole interactions and how they can be mitigated with specific trap designs.

Contribution

A discrete random-walk model incorporating interactions was developed to simulate and analyze IX trapping in various trap configurations.

Findings

Dipole-dipole interactions significantly influence IX trapping.

Small, deep traps effectively mitigate dipole interaction effects.

Atomic defects and moire potentials can realize such traps.

Abstract

Transition metal dichalcogenide heterostructures can host interlayer excitons (IXs), which consist of electrons and holes spatially separated in different layers. IXs possess permanent dipoles and have proven to offer a wealth of novel physics. We develop a discrete, random-walk model which includes annihilation and repulsion interactions among IXs. Using this model, we simulate the trapping of IXs in traps of different depths, densities, and shapes. Our results show that dipole-dipole interactions play an important role in regulating IX trapping. The effects of dipole interactions can be mitigated with small, deep traps which are realizable with atomic defects and moire potentials.