Super-correlated radiance in nonlinear photonic waveguides

TL;DR

This paper investigates how nonlinear photonic waveguides induce a super-correlated decay process in multiple emitters, revealing new collective effects driven by photon interactions and correlations.

Contribution

It introduces an effective Markovian theory for collective decay in nonlinear waveguides, uncovering a novel super-correlated decay phenomenon beyond traditional super- and subradiance.

Findings

Identification of super-correlated decay where all emitters are simultaneously excited or ground

Derivation of an effective theory modeling complex decay dynamics in nonlinear environments

Potential for experimental observation in state-of-the-art waveguide QED setups

Abstract

We study the collective decay of two-level emitters coupled to a nonlinear waveguide, for example, a nanophotonic lattice or a superconducting resonator array with strong photon-photon interactions. Under these conditions a new decay channel into bound photon pairs emerges, through which spatial correlations between emitters are established by regular interference as well as interactions between the photons. We derive an effective Markovian theory to model the resulting decay dynamics of an arbitrary distribution of emitters and identify collective effects beyond the usual phenomena of super- and subradiance. Specifically, in the limit of many close-by emitters, we find that the system undergoes a super-correlated decay process where either all the emitters are in the excited state or in the ground state, but not in any of the intermediate states. The predicted effects can be probed in state-of-the-art waveguide QED experiments and provide a striking example of how the dynamics of open quantum systems can be modified by many-body effects in a non-harmonic environment.