Quantum correlations and multiatom excitation dynamics in an atom-waveguide interface

The atom-waveguide interface mediates strong and long-range light-matter interactions through guided modes. In this one-dimensional system, we theoretically investigate the excitation localization of multiple atomic excitations under strong position disorder and collective subradiant decays of multiply excited atoms bound in space. Deep in the localization side, we obtain the time evolutions of quantum correlations via Kubo cumulant expansions, which arise initially and become finite and leveled afterward, overtaking those without disorder. In this interface, we also analyze their average density-density and modified third-order correlations, which can arise, and finite correlations can be sustained for long time. The time-evolved quantum correlations can give insights into the studies of few-body localization phenomenon and nonequilibrium dynamics in open quantum systems.