Hydrodynamics of charged two-dimensional Dirac systems I: thermo-electric transport

In this paper we study thermo-electric transport in interacting two-dimensional Dirac-type systems using a phenomenological Boltzmann approach. We consider a setup that can accommodate electrons, holes, and collective modes. In the first part of the paper we consider the electron-hole hydrodynamics, a model that is popular in the context of graphene, and its transport properties. In a second part, we propose a novel type of hydrodynamics. In that setup, the `fluid' consists of electrons, holes, and plasmons. We study its transport properties, especially the thermo-electric behavior. The results of this part can also be adapted to the study of a fluid consisting of electrons and phonons. This paper is accompanied by a technical paper in which we give a detailed derivation of the Boltzmann equations and the encoded conservation laws.