Finding a theoretical framework to explain how phenomenological transport laws on macroscopic scales emerge from microscopic deterministic dynamics poses one of the most significant challenges of condensed matter physics. In recent years, the advent of the generalized hydrodynamics in integrable quantum systems and more recent studies of quantum chaos and its relation to transport, reinvigorated the field of nonequilibrium physics in spin chains. Numerous results were found: lower bounds to diffusion constants, exact expressions for diffusion coefficients and remarkable anomalous features of transport in quantum and classical chains, deeply related to the Kardar-Parisi-Zhang dynamical universality class.
I will present an overview of such results with a particular focus on anomalous transport and its relation to non-linear hydrodynamics.
Refs: arXiv:1812.00767, arXiv:1911.01995, arXiv:2001.06432.