Excitonic transport driven by repulsive dipolar interaction in a van der Waals heterostructure

TL;DR

This paper investigates how repulsive dipolar interactions influence exciton transport in van der Waals heterostructures, revealing enhanced diffusion and potential for excitonic device applications.

Contribution

It demonstrates the impact of repulsive dipolar interactions on exciton dynamics in van der Waals heterostructures using spatial and time-resolved photoluminescence imaging.

Findings

Dipolar interactions modify exciton diffusion and induce drift.

Diffusion coefficient increases by an order of magnitude due to interactions.

Electrical control combined with interactions offers new device possibilities.

Abstract

Dipolar bosonic gases are currently the focus of intensive research due to their interesting many-body physics in the quantum regime. Their experimental embodiments range from Rydberg atoms to GaAs double quantum wells and van der Waals heterostructures built from transition metal dichalcogenides. Although quantum gases are very dilute, mutual interactions between particles could lead to exotic many-body phenomena such as Bose-Einstein condensation and high-temperature superfluidity. Here, we report the effect of repulsive dipolar interactions on the dynamics of interlayer excitons in the dilute regime. By using spatial and time-resolved photoluminescence imaging, we observe the dynamics of exciton transport, enabling a direct estimation of the exciton mobility. The presence of interactions significantly modifies the diffusive transport of excitons, effectively acting as a source of drift force and enhancing the diffusion coefficient by one order of magnitude. The repulsive dipolar interactions combined with the electrical control of interlayer excitons opens up appealing new perspectives for excitonic devices.