Engineering topological exciton structures in two-dimensional semiconductors by a periodic electrostatic potential

TL;DR

This paper demonstrates how to engineer topological exciton structures in 2D semiconductors using a periodic electrostatic potential, revealing topological phases and edge states with potential for quantum applications.

Contribution

It introduces a method to create topological exciton bands in layered transition metal dichalcogenides via remote electrostatic patterning, a novel approach in the field.

Findings

Topological phase diagrams depend on potential strength and wavelength.

Interlayer excitons can have topologically nontrivial bands with small bandwidth.

Monolayer excitons exhibit topological bands and helical edge states near 2p energy levels.

Abstract

We propose to engineer topological exciton structures in layered transition metal dichalcogenides through hybridizing different Rydberg states, which can be induced by a periodic electrostatic potential remotely imprinted from charge distributions in adjacent layers. Topological phase diagrams are obtained for potentials with various strengths and wavelengths. We find the lowest band of the interlayer exciton can become topologically nontrivial, which exhibits a small bandwidth as well as quantum geometries well suited for realizing the bosonic fractional Chern insulator. For monolayer excitons, topological bands and in-gap helical edge states can emerge near the energy of 2p states.