Strong Dipole-Dipole Interactions via Enhanced Light-Matter Coupling in Composite Nanofiber Waveguides

TL;DR

This paper explores enhanced light-matter interactions in composite nanofiber waveguides, demonstrating improved emitter coupling, increased entanglement potential, and robustness, with implications for quantum communication technologies.

Contribution

It introduces a comprehensive analysis of emitter interactions in dual-fiber waveguides, revealing significantly improved coupling efficiencies and entanglement capabilities over single-fiber systems.

Findings

Coupling efficiencies and Purcell factors are greatly enhanced.

Entanglement can be generated even when absent in single-fiber systems.

Composite waveguides show robustness across various configurations.

Abstract

We study the interaction of emitters with a composite waveguide formed from two parallel optical nanofibers in currently unexplored regimes of experimental importance for atomic gases or solid-state emitters. Using the exact dyadic Green's function we comprehensively investigate the coupling efficiency and the fiber-induced Lamb shift accounting for variations in emitter positions and fiber configurations. This reveals coupling efficiencies and Purcell factors that are enhanced considerably beyond those using a single fiber waveguide, and robustness in the figures of merit. We finally investigate resonant dipole-dipole interactions and the generation of entanglement between two emitters mediated through the composite waveguide under excitation. We show that the concurrence can be enhanced for two fiber systems, such that entanglement may be present even in cases where it is zero for a single fiber. All-fiber systems are simple in construction and benefit from a wealth of existing telecommunications technologies, whilst enjoying strong couplings to emitters and offering novel light-matter functionalities specific to slot waveguides.