Spatial filtering of interlayer exciton ground state in WSe2/MoS2 heterobilayer

TL;DR

This paper demonstrates spatial filtering of the interlayer exciton ground state in WSe2/MoS2 heterobilayers, enabling better control and study of excitonic states for high-temperature quantum phenomena.

Contribution

It introduces a method to spatially filter the IX ground state based on its spatial profile, aiding in the exploration of correlated excitonic states.

Findings

Successful spatial separation of IX ground state from other states.

Identification of moire IX modes by energy and spatial distribution.

Validation of the rate-diffusion model for cascading emission.

Abstract

Long-life interlayer excitons (IXs) in transition metal dichalcogenide (TMD) heterostructure are promising for realizing excitonic condensates at high temperatures. Critical to this objective is to separate the IX ground state (the lowest energy of IX state) emission from other states emissions. Filtering the IX ground state is also essential in uncovering the dynamics of correlated excitonic states, such as the excitonic Mott insulator. Here, we show that the IX ground state in WSe2/MoS2 heterobilayer can be separated from other states by its spatial profile. The emissions from different moire IX modes are identified by their different energies and spatial distributions, which fits well with the rate-diffusion model for cascading emission. Our results show spatial filtering of the ground state mode and enrich the toolbox to realize correlated states at elevated temperatures.