Condensed Matter Seminar: "Non-equilibrium quasi-particles in disordered superconductors"

Experimentally, the concentration of quasi-particles in gapped superconductors always largely exceeds the equilibrium one at low temperatures. Since these quasiparticles are detrimental for many applications, it is important to understand the origin of the excess. We demonstrate that the dynamics of quasiparticles localized at spatial fluctuations of the gap edge becomes exponentially slow. This may give rise to the observed excess quasiparticles in the presence of a vanishingly weak non-equilibrium agent.