Quasi-Chiral Interactions between Quantum Emitters at the Nanoscale

TL;DR

This paper explores tunable quasi-chiral interactions between quantum emitters near a metal surface, revealing regimes with sharp spectral features and strong photon correlations driven by subradiant states.

Contribution

It introduces a combined classical and quantum electrodynamics framework to analyze and demonstrate quasi-chiral coupling in a highly tunable nanoscale system.

Findings

Identification of nonreciprocal emitter interactions

Discovery of a quasi-chiral regime with subradiant states

Observation of sharp spectral features and photon correlations

Abstract

We present a combined classical and quantum electrodynamics description of the coupling between two circularly-polarized quantum emitters held above a metal surface supporting surface plasmons. Depending on their position and their natural frequency, the emitter-emitter interactions evolve from being reciprocal to nonreciprocal, which makes the system a highly tunable platform for chiral coupling at the nanoscale. By relaxing the stringent material and geometrical constraints for chirality, we explore the interplay between coherent and dissipative coupling mechanisms in the system. Thus, we reveal a quasi-chiral regime in which its quantum optical properties are governed by its subradiant state, giving rise to extremely sharp spectral features and strong photon correlations.