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

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 subradiant 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 subradiant 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.

Control of Localized Multiple Excitation Dark States in Waveguide QED

“…In most cases, studies and experiments on subradiance focus on manipulating only a single excitation, i.e., they limit their scope to the lowest of the so-called Dicke manifold [9][10][11][12][13][14][15][16][17][18][19][20][21]. Many-body subradiant states have attracted more interest only recently, but in general the preparation and manipulation of such states remains challenging as they are typically very delocalized.…”