Condensed Matter Theory Seminar - Filip Marijanovic - ETH Zurich

Picosecond current transport in dirty superconductors

Recent picosecond current pulse experiments enable the study of non-perturbative ultra-fast response of superconductors. Motivated by these experiments, we develop a theoretical analysis of non-equilibrium dynamics of the superconducting order parameter on picosecond timescale. Within the Keldysh two-time framework, we model the response of the system, focusing on the case of dirty superconductors, described by the Usadel equation. Our results show an asymmetric response of the gap, where the gap suppression happens much quicker than gap recovery. We also show that the current pulse transmitivity strongly depends on the interplay between gap, pulse time and quasi-particle relaxation time.

Host: Leonid Glazman