Kagome Flatbands for Coherent Exciton-Polariton Lasing

TL;DR

This paper demonstrates the realization and control of flatband exciton-polariton condensates in Kagome lattices, revealing enhanced coherence properties and showcasing their potential for studying flatband physics and microlaser applications.

Contribution

It introduces a coupled microcavity implementation of Kagome lattices with controllable flatbands and investigates the coherence properties of polariton condensates within these flatbands.

Findings

Enhanced coherence time due to flatband localization

Selective condensation into flatbands achieved

Potential for flatband-based microlaser arrays

Abstract

Kagome lattices supporting Dirac cone and flatband dispersions are well known as a highly frustrated, two-dimensional lattice system. Particularly the flatbands therein are attracting continuous interest based on their link to topological order, correlations and frustration. In this work, we realize coupled microcavity implementations of Kagome lattices hosting exciton-polariton quantum fluids of light. We demonstrate precise control over the dispersiveness of the flatband as well as selective condensation of exciton-polaritons into the flatband. Subsequently, we focus on the spatial and temporal coherence properties of the laser-like emission from these polariton condensates that are closely connected to the flatband nature of the system. Notably, we find a drastic increase in coherence time due to the localization of flatband condensates. Our work illustrates the outstanding suitability of the exciton-polariton system for detailed studies of flatband states as a platform for microlaser arrays in compact localized states, including strong interactions, topology and non-linearity.