Bistable topological insulator with exciton-polaritons

TL;DR

This paper demonstrates optical bistability and controllable edge state propagation in a topological insulator made of exciton-polaritons within a honeycomb microcavity lattice, advancing topological photonics applications.

Contribution

It introduces a topological insulator platform with exciton-polaritons exhibiting bistability and tunable edge state propagation, a novel combination for photonic devices.

Findings

Observation of bistability in topological edge states

Control of edge state propagation via pump parameters

Broad dynamical stability range achieved

Abstract

Functionality of many nonlinear and quantum optical devices relies on the effect of optical bistability. Using the microcavity exciton-polaritons in a honeycomb arrangement of microcavity pillars, we report the resonance response and bistability of the topological edge states. A balance between the pump, loss and nonlinearity ensures a broad range of dynamical stability and controls the distribution of power between counter-propagating states on the opposite edges of the honeycomb lattice stripe. Tuning energy and polarization of the pump photons, while keeping their momentum constant, we demonstrate control of the propagation direction of the dominant edge state. Our results facilitate development of new applications of topological photonics in practical devices.