Manipulating Moiré Excitons in Two-Dimensional Quantum Systems via Optical Microcavities

Abstract

Moiré-trapped interlayer excitons within two-dimensional (2D) moiré superlattices offer a remarkably versatile and adaptable platform, enabling an extensive exploration of dipole interactions and many-body correlations in the realm of 2D quantum systems. Conversely, optical microcavities, capable of confining photons within a confined space, profoundly amplify the interplay between light and matter, ushering in a new era of possibilities for photonics research. However, the intricate synergy between moiré potential and optical microcavities remains shrouded in uncertainty. Here, we present a precise integration of a twisted WSe2/WSe2 homobilayer with an optical microcavity, forging a cooperative alliance between moiré excitons and microcavity photons. Our investigation unveils highly localized moiré-enhanced emission in the suspended WSe2/WSe2 homobilayer, distinguished by remarkably sharp emission lines with peak widths reduced by a factor of three, alongside distinctive valleytronic attributes. Notably, our pioneering work uncovers a profound transformation in the nature of moiré exciton-dipole interactions within the suspended twist-angle WSe2/WSe2 homobilayer. This transformation triggers an unprecedented shift from repulsive to attractive interactions, culminating in the emergence of a robust moiré biexciton phase—an occurrence previously confined to theoretical predictions. Our findings provide essential insights into the cooperative interplay between moiré excitons and optical microcavities, illuminating the underlying physics and charting a course for future research and technological advancements in this captivating realm.