Foundation of Statistical Mechanics under experimentally realistic conditions

Peter Reimann, Condensed Matter Theory, Bielefeld

We demonstrate the equilibration of isolated macroscopic quantum systems, prepared in non-equilibrium mixed states with significant population of many energy levels, and observed by instruments with a reasonably bound working range compared to the resolution limit. Both properties are fulfilled under many, if not all, experimentally realistic conditions. At equilibrium, the predictions and limitations of Statistical Mechanics are recovered. Finally, the imitation of statistical ensembles in and out of equilibrium by pure (zero entropy) states is discussed.