Photonic Chern insulators from two-dimensional atomic lattices interacting with a single surface plasmon polariton

TL;DR

This paper investigates how two-dimensional atomic lattices coupled with surface plasmon polaritons can host topological photonic states with potential applications in unidirectional photon transport.

Contribution

It introduces a computational approach to model topological polaritonic bands in atomic lattices interacting with surface plasmons, highlighting the emergence of robust edge states.

Findings

Topological gaps with various Chern numbers can be realized.

Design of topologically protected edge states for unidirectional photon emission.

Challenges identified in achieving higher Chern number bands.

Abstract

We study the polaritonic bandstructure of two-dimensional atomic lattices coupled to a single excitation of a surface plasmon polariton mode. We show the possibility of realizing topological gaps with different Chern numbers by having resonant atomic transitions to excited states with different angular momentum. We employ a computational method based on the recently proposed Dirichlet-to-Neumann (DtN) map technique which accurately models non-Markovian dynamics as well as interactions involving higher-order electric and magnetic multipole transitions. We design topologically robust edge states which are used to achieve unidirectional emission and non-reciprocal transmission of single photons. We also point out the challenges in realizing bands with higher Chern numbers in such systems.