CMT Seminar Romain Vasseur (University of California, Berkeley) "Symmetry constraints and topological phases far from equilibrium"

In this talk, I will describe some general constraints on the existence of many-body localized (MBL) phases in the presence of global symmetries.  Based only on representation theory, I will derive some general Mermin-Wagner-type principles governing the possible fates of non-equilibrium dynamics in isolated, disordered quantum systems.  In particular, I will show that MBL cannot exist in the presence of non-Abelian symmetries.  Consequences for the classification of MBL protected topological phases (and Floquet phases) will be discussed.