Dissipation and noise in strongly driven Josephson junctions

In circuit quantum electrodynamics systems, the quasiparticle-related losses in Josephson junctions are suppressed due to the gap in the superconducting density of states which is much higher than the typical energy of a microwave photon. In this work, we show that a strong drive even at frequency lower than the double superconducting gap enables dissipation in the junctions due to photon-assisted breaking of the Cooper pairs. Both the decay rate and noise strength associated with the losses are sensitive to the dc phase bias of the junction and can be tuned in a broad range by the amplitude and the frequency of the external driving field, making the suggested mechanism potentially attractive for designing tunable dissipative elements. Furthermore, pronounced memory effects in the driven Josephson junctions render them perspective for both theoretical and experimental study of non-Markovian physics in superconducting quantum circuits. We illustrate our theoretical findings by studying the spectral properties and the steady state population of a low impedance resonator coupled to the driven Josephson junction.