Cavity induced many-body localization

In this paper, we explore the feasibility of achieving many-body localization in the context of cavity quantum electrodynamics at strong coupling. Working with a spinless electronic Hubbard chain sitting coupled to a single-mode cavity, we show that the global coupling between electrons and photons---which generally would be expected to delocalize the fermionic excitations---can instead favor the appearance of localization. This is supported by a high-frequency expansion that correctly accounts for electron-photon interaction at strong coupling, as well as numerical calculations in both single-particle and many-body regimes. We find evidence that many-body localization may survive strong quantum fluctuations of the photon number by exploring energy dependence, seeing signatures of localization down to photon numbers as small as $n\ensuremath{\sim}2$.