Quench Dynamics in Interacting one-dimensional systems
28.06.2011 at 10:00
Due to experiments in cold-atomic gases, the problem of
quench dynamics which is the unitary time evolution of interacting quantum systems arising due to
sudden change in system parameters has become a topic of great current interest.
Fundamental questions such as whether systems thermalize at long times after a quench,
what is the time-scale associated with thermalization, and the role played by integrability and system size
are still largely open and a frontier of current research.
In this talk I will present results for the time-evolution of some 1-dimensional models and first show how
non-thermal steady states can arise at long times, at least for exactly solvable models such as the XX
spin-chain and the Luttinger liquid. Next I will address the issue of how stable these
steady-states are to non-trivial interactions or mode-coupling. Employing analytic approaches such as
renormalization group and random-phase-approximation, I will show that even infinitesimally weak
interactions or mode-coupling generate a dissipation (and hence a finite lifetime for the modes), and also
However the notion of the "temperature" even with interactions is only approximate, and the
fluctuation-dissipation theorem is in general not obeyed.
A318 Theresienstrasse 37