Photon-mediated interactions near a Dirac photonic crystal slab

TL;DR

This paper develops a semi-analytical model to study photon-mediated interactions near Dirac points in realistic photonic crystal slabs, revealing optimal emitter positions and the nature of collective interactions, guiding future experiments.

Contribution

It introduces a semi-analytical theory for dipole radiation near Dirac points in realistic photonic structures, enabling detailed analysis of emitter interactions across the entire unit cell.

Findings

Identifies emitter positions that maximize interaction strength and range.

Discovers positions where interactions switch from coherent to dissipative.

Provides insights for designing Dirac light-matter interfaces.

Abstract

Dirac energy-dispersions are responsible of the extraordinary transport properties of graphene. This motivated the quest for engineering such energy dispersions also in photonics, where they have been predicted to lead to many exciting phenomena. One paradigmatic example is the possibility of obtaining power-law, decoherence-free, photon-mediated interactions between quantum emitters when they interact with such photonic baths. This prediction, however, has been obtained either by using toy-model baths, which neglect polarization effects, or by restricting the emitter position to high-symmetry points of the unit cell in the case of realistic structures. Here, we develop a semi-analytical theory of dipole radiation near photonic Dirac points in realistic structures that allows us to compute the effective photon-mediated interactions along the whole unit cell. Using this theory, we are able to find the positions that maximize the emitter interactions and their range, finding a trade-off between them. Besides, using the polarization degree of freedom, we also find positions where the nature of the collective interactions change from being coherent to dissipative ones. Thus, our results significantly improve the knowledge of Dirac light-matter interfaces, and can serve as a guidance for future experimental designs.