Foundation of statistical mechanics under experimentally realistic conditions

Phys Rev Lett. 2008 Nov 7;101(19):190403. doi: 10.1103/PhysRevLett.101.190403. Epub 2008 Nov 7.


We demonstrate the equilibration of isolated macroscopic quantum systems, prepared in nonequilibrium mixed states with a significant population of many energy levels, and observed by instruments with a reasonably bound working range compared to the resolution limit. Both properties are satisfied under many, if not all, experimentally realistic conditions. At equilibrium, the predictions and limitations of statistical mechanics are recovered.