Cavity Quantum Enhancement of Superconductivity*

Standard superconductors are known to exhibit a number of fascinating and potentially useful phenomena when driven away from thermal equilibrium by coherent classical electromagnetic radiation. These non-equilibrium effects can often lead to an enhancement in the strength of the superconducting gap and its manifestations. We aim to understand what happens when the classical electromagnetic field is replaced by a fluctuating quantum electromagnetic field, as may be found in a microwave cavity resonator. We show that in the lossy regime non-equilibrium cavity photons can rid the superconductor of deleterious quasiparticles, thereby enhancing the superconducting gap strength. This proposed quantum enhancement of superconductivity opens the door to the study of more exotic phenomena which may arise when superconductors are subjected to cavity quantum electrodynamic environments.