Optical signature of cascade transitions between moir\'e interlayer excitons

TL;DR

This paper investigates cascade transitions between moiré interlayer excitons in 2D heterostructures, revealing how energy levels can be manipulated for potential quantum information and laser applications through time- and energy-resolved photoluminescence.

Contribution

It demonstrates cascade transitions between moiré interlayer excitons and shows how to excite lower-energy excitons to higher-energy states, enabling population inversion.

Findings

Observation of cascade transitions between moiré interlayer excitons.

Lower-energy excitons can be excited to higher-energy states.

Potential for exciton population inversion in 2D heterostructures.

Abstract

Cascade transition between energy levels has important applications, such as in quantum information protocols and quantum cascade lasers. In two-dimensional heterostructure, the moir\'e superlattice potential can result in multiple interlayer exciton (IX) energy levels. We demonstrate the cascade transitions between such moir\'e IXs by performing time- and energy-resolved photoluminescence measurements. We show that the lower-energy moir\'e IX can be excited to higher-energy ones, facilitating IX population inversion.