# Non-invasive control of excitons in two-dimensional materials

## TL;DR

This paper explores how structured dielectric environments can non-invasively manipulate excitons in 2D semiconductors, enabling potential trapping and guiding of higher excitonic states on nanometer scales.

## Contribution

It introduces a model describing how dielectric structuring influences exciton energy landscapes in 2D materials, revealing a novel inverted potential effect.

## Key findings

- Higher excitons are attracted to high dielectric regions.
- Energy variations occur on nanometer length scales.
- Potential for exciton trapping and guiding using dielectric patterning.

## Abstract

We investigate how external screening shapes excitons in two-dimensional (2d) semiconductors embedded in laterally structured dielectric environments. An atomic scale view of these elementary excitations is developed using models which apply to a variety of materials including transition metal dichalcogenides (TMDCs). We find that structured dielectrics imprint a peculiar potential energy landscape on excitons in these systems: While the ground-state exciton is least influenced, higher excitations are attracted towards regions with high dielectric constant of the environment. This landscape is "inverted" in the sense that low energy excitons are less strongly affected than their higher energy counterparts. Corresponding energy variations emerge on length scales of the order of a few unit cells. This opens the prospect of trapping and guiding of higher excitons by means of tailor-made dielectric substrates on ultimately small spatial scales.