Dynamics of highly excited many-body states — diffusion and localization at finite entropy
Tuesday, February 12, 2013 – 3:15pm – 4:30pm
College of Staten Island of the City College of New York
I will survey some recent ideas and results on transport and dynamics of strongly excited interacting systems with and without intrinsic disorder. While in some cases existence of macroscopic diffusion can be verified, in other cases, e.g. in the presence of localization on microscopic scales, emergence of diffusion may be thwarted. The existence of such many-body localized phases and phase transitions separating them from the diffusive phase appears to crucially depend on the quantum mechanical nature of particles’ dynamics and a locally bound spectrum. The phenomenon is otherwise rather generic, provided the disorder is strong and interactions are sufficiently short ranged. While strongly localized, these many-body systems possess an extended set of exact conservation laws which we will construct explicitly and use to derive the effective Hamiltonian and the dephasing rates.