Dark state semilocalization of quantum emitters in a cavity

We study a disordered ensemble of quantum emitters collectively coupled to a lossless cavity mode. The latter is found to modify the localization properties of the "dark" eigenstates, which exhibit a character of being localized on multiple, noncontiguous sites. We denote such states as semi-localized and characterize them by means of standard localization measures. We show that those states can very efficiently contribute to coherent energy transport. Our paper underlines the important role of dark states in systems with strong light-matter coupling.