Condensed Matter Physics Seminar

The time dependent fermionic Hubbard model represents a paradigm for the description of correlated electrons in nonequilibrium. Performing a small interaction quench allows to observe different relaxation timescales for the kinetic energy and the momentum distribution, known as prethermalization, already by means of a perturbative calculation. The time scales for the thermalization of both observables relate to the buildup and the subsequent relaxation of a nonequilibrium quasiparticle picture. Their separation may open a time window to observe elusive nonequilibrium transient phenomena (e.g. nonequilibrium BCS physics) and is interesting from its own right. Moreover, time scale separation motivates the development of composite tools to study the transient dynamics of excited many-particle systems. For the initial time regime perturbative or self-consistent mean field approaches are suitable. Subsequent relaxation can be modeled by linking the early evolution to an effective quantum Boltzmann description.