Energy (and spin) transport in the thermal phase of the disordered Heisenberg chain
We study energy transport at high temperature in the thermal phase of the disordered Heisenberg chain . Starting from nonequilibrium initial conditions that are either well within linear response or well outside of it, we show that a phenomenological hydrodynamic description captures the mechanism for equilibration. In particular, an energy diffusion constant is identified which vanishes in the thermal phase even before the localisation transition: the thermal phase is separated into diffusive and subdiffusive regimes. If time permits, similar results will be shown to hold for the transport of spin ; in particular a critical length scale is seen to exist below which the disorder is irrelevant.
 V. K. Varma, A. Lerose, F. Pietracaprina, J. Goold, A. Scardicchio, arxiv 1511.09144
 M. Znidaric, A. Scardicchio, V. K. Varma, arxiv 16xx.xxxx