# Exciton routing in the heterostructure of TMD and paraelectrics

## TL;DR

This paper introduces a method to control and route excitons in TMD monolayers by exploiting the temperature-sensitive dielectric properties of a paraelectric substrate, enabling spatial energy modulation and exciton flow.

## Contribution

It presents a novel approach for exciton routing using substrate dielectric permittivity changes induced by temperature variations in TMD heterostructures.

## Key findings

- Substrate temperature significantly affects TMD exciton properties.
- Localized heating creates exciton energy gradients and directs exciton flow.
- Large dielectric screening in SrTiO₃ enhances exciton energy modulation.

## Abstract

We propose a scheme for the spatial exciton energy control and exciton routing in a transition metal dichalcogenide (TMD) monolayer which lies on a quantum paraelectric substrate. It relies on the ultrasensitive response of the substrate dielectric permittivity to temperature changes, allowing for spatially inhomogeneous screening of Coulomb interaction in a monolayer. As an example, we consider the heterostructure of TMD and strontium titanate oxide SrTiO$_3$, where large dielectric screening can be attained. We study the impact of substrate temperature on the characteristic electronic features of TMD monolayers such as the particle bandgap and exciton binding energy, Bohr radius and nonlinearity (an exciton-exciton interaction). The combination of particle bandgap and exciton binding energy modulation results in the shift of the exciton resonance energy. Applying local heating, we create spatial patterns with varying exciton resonant energy and an exciton flow towards the energetically lower region of the sample.