Vendredi 26 avril 2013 à 14h15

Auditoire Stueckelberg, Ecole de Physique

### Trajectory phase transitions in quantum non-equilibrium

**Juan P. Garrahan**, University of Nottingham, UK

###### It is often assumed that if one understands the static or thermodynamic properties of a physical system then its dynamical behaviour is easy to anticipate. But this is not true in general: the dynamics of many-body systems can be much richer than what one would infer from their statics. This dynamical richness is revealed by considering strictly dynamical observables. The full statistical characteristics of such quantities encode the dynamical properties of the system at hand. This observation has led to the emergence of the field of "full counting statistics", through parallel developments in stochastic systems and in mesoscopics. In effect, by considering the large-deviations of the FCS of dynamical observables it is possible to derive a "statistical mechanics of trajectories", which is to trajectories of the dynamics what equilibrium statistical mechanics is to configurations of the statics. In this talk I will describe this approach and how it can be applied to the study of quantum non-equilibrium systems, both for systems which are open (i.e. which interacting with an environment) and systems which are closed. I will show how this method allows to reveal unexpected complexity in the dynamical phase structure of many-body systems, and will discuss how in principle the predicted trajectory phase transitions could be probed experimentally.