Quantum materials as a possible host for new kinds of hydrodynamics

The past decade has seen a huge wave of interest in the possibility of hydrodynamic transport of electrons and/or phonons in quantum materials.  There are now dozens of experiments that are approaching consensus on a weakly viscous hydrodynamic regime in e.g. monolayer graphene.  In this talk, I will point out that other materials could have much more interesting hydrodynamic phenomena of electrons and/or phonons, due to one or both of the following features: (1) the possibility of strong electron-phonon coupling leading to a hybrid electron-phonon fluid with highly unusual transport properties; (2) small crystalline point groups leading to anisotropic hydrodynamic transport coefficients, many of which have (as far as I know) never been seen before.   I will very quickly sketch how these claims can be understood using quantum kinetic theory.