Non-Hermitian topological exciton-polariton corner modes

TL;DR

This paper predicts non-Hermitian topological corner modes in 2D exciton-polariton lattices under non-resonant pumping, revealing unique localization and propagation properties that differ from traditional topological systems.

Contribution

It introduces a higher-dimensional non-Hermitian topological phase in exciton-polariton systems, expanding the understanding of topological effects beyond existing models.

Findings

Eigenstates localized at system corners

Propagation of signals around defects in the bulk

Enhanced measurement accuracy of polariton interactions

Abstract

We theoretically study two-dimensional exciton-polariton lattices and predict that non-Hermitian topological corner modes can be formed under non-resonant pumping. As a generalization of the non-Hermitian skin effect, all eigenstates are localized at the two corners in our model. This is also a higher dimensional topology compared to other proposals in exciton-polariton systems and we find that it allows propagating signals in the bulk of the system to travel around defects, which is not possible in one-dimensional topological lattices or two-dimensional lattices with Hermitian edge states. Furthermore, as all polariton states are localized away from an excitation spot, the system offers an opportunity for more accurate measurement of the polariton-polariton interaction strength as the pump-induced exciton-reservoir is spatially separated from all polariton states.