Nonequilibrium dynamics of strongly coupled phonon-mediated superconductors
CFEL Theory Seminar
- Datum: 05.07.2016
- Uhrzeit: 14:00 - 15:00
- Vortragende(r): Yuta Murakami
- Fribourg University
- Ort: CFEL (Bldg. 99)
- Raum: Seminar Room III, EG.080
- Gastgeber: Martin Eckstein

In this talk we discuss our recent work on the dynamics of
strongly-coupled phonon-mediated superconductors. Our studies are based
on the nonequilibrium Migdal approximation (the GW approximation for
electron-phonon systems) implemented in the framework of dynamical
mean-filed theory, which enables us to study the phonon dynamics as well
as the electron dynamics. Based on an analysis of weak excitations, we
discuss the energy scale and the lifetime of the amplitude Higgs mode
beyond the conventional BCS regime, and explain the effects of the
phonon dynamics on the Higgs mode. We also predict a new type of
amplitude oscillation in the strong-coupling regime. In the case far
from equilibrium, we show that there exists an additional critical point
other than the thermal one, which controls the relaxation dynamics.