Manipulating Topological Polaritons in Optomechanical Ladders

TL;DR

This paper explores how optomechanical interactions can induce and control topological phases in polaritons within coupled optical and mechanical SSH chains, revealing novel edge states and simulating higher Chern number insulators.

Contribution

It demonstrates that optomechanical coupling can generate topologically nontrivial polariton phases even when individual chains are trivial, and introduces methods to simulate higher Chern number insulators.

Findings

Topological phase diagrams divided into six regions by four boundaries.

A topologically nontrivial phase arises from optomechanical interactions.

Six edge states appear in a phase with only two nontrivial bands.

Abstract

We propose to manipulate topological polaritons in optomechanical ladders consisting of an optical Su-Schrieffer-Heeger (SSH) chain and a mechanical SSH chain connected through optomechanical (interchain) interactions. We show that the topological phase diagrams are divided into six areas by four boundaries and that there are four topological phases characterized by the Berry phases. We find that a topologically nontrivial phase of the polaritons is generated by the optomechanical interaction between the optical and mechanical SSH chains even though they are both in the topologically trivial phases. Counter-intuitively, six edge states appear in one of the topological phases with only two topological nontrivial bands, and some edge states are localized near but not at the boundaries of an open-boundary ladder. Moreover, a two-dimensional Chern insulator with higher Chern numbers is simulated by introducing proper periodical adiabatic modulations of the driving amplitude and frequency. Our work not only opens a route towards topological polaritons manipulation by optomachanical interactions, but also will exert a far-reaching influence on designing topologically protected polaritonic devices.