Lieb polariton topological insulators

TL;DR

This paper predicts the emergence of robust, unidirectional topological edge states in Lieb lattice microcavities due to spin-orbit coupling and Zeeman effects, enabling stable edge solitons in exciton-polariton systems.

Contribution

It introduces a novel topological insulator model based on Lieb lattices in microcavities, highlighting the formation of nonlinear, robust edge states and solitons.

Findings

Unidirectional linear topological edge states are predicted in Lieb lattices.

Periodic nonlinear edge states emerge from linear ones and are highly localized.

Robustness of these states enables stable dark solitons moving along the edge.

Abstract

We predict that the interplay between the spin-orbit coupling, stemming from the TE-TM energy splitting, and the Zeeman effect in semiconductor microcavities supporting exci- ton-polariton quasi-particles results in the appearance of unidirectional linear topological edge states when the top microcavity mirror is patterned to form a truncated dislocated Lieb lattice of cylindrical pillars. Periodic nonlinear edge states are found to emerge from the linear ones. They are strongly localized across the interface and they are remarkably robust in comparison to their counterparts in hexagonal lattices. Such robustness makes possible the existence of nested unidirectional dark solitons that move steadily along the lattice edge.