Thermal transport in two-dimensional disordered electron systems at intermediate temperatures*

Theoretical studies of transport properties of two-dimensional electron gases often focus on two limiting cases: (i) The diffusive regime that occurs at low temperatures where inelastic electron-electron scattering is substantially weaker than scattering by disorder. (ii) The hydrodynamic limit characterized by strong electron-electron scattering which requires relatively high temperatures. The latter has been widely studied in the context of strongly correlated electron systems and graphene. Here, we report a study of electron transport in an intermediate regime where both electron-electron scattering and scattering on impurities are equally important. To address this regime, we first analyzed a simplified kinetic equation which we supplemented by a more detailed analysis of the elastic and inelastic scattering terms. In particular, we derived the thermal conductivity of a degenerate electron system at intermediate temperatures.