Sub-radiant states for imperfect quantum emitters coupled by a nanophotonic waveguide

TL;DR

This paper explores how two quantum emitters coupled via a nanophotonic waveguide can form sub-radiant states even with dephasing, providing insights for quantum technology applications in solid-state environments.

Contribution

It demonstrates the creation and detection of sub-radiant states in solid-state quantum emitters mediated by realistic nanophotonic waveguides, considering dephasing effects.

Findings

Sub-radiant signatures diminish in intensity with increased dephasing.

Photon correlation measurements reveal sub-radiance despite dephasing.

Separate pumping enhances sub-radiant state population.

Abstract

Coherent interactions between quantum emitters in tailored photonic structures is a fundamental building block for future quantum technologies, but remains challenging to observe in complex solid-state environments, where the role of decoherence must be considered. Here, we investigate the optical interaction between two quantum emitters mediated by one-dimensional waveguides in a realistic solid-state environment, focusing on the creation, population and detection of a sub-radiant state, in the presence of dephasing. We show that as dephasing increases, the signatures of sub-radiance quickly vanish in intensity measurements yet remain pronounced in photon correlation measurements, particularly when the two emitters are pumped separately so as to populate the sub-radiant state efficiently. The applied Green's tensor approach is used to model a photonic crystal waveguide, including the dependence on the spatial position of the integrated emitter. The work lays out a route to the experimental realization of sub-radiant states in nanophotonic waveguides containing solid-state emitters.