Electron-electron scattering limits thermal conductivity of metals underextremely high electron temperatures

We report on the thermal transport properties of noble metals (gold, silver and copper) under conditions of extremely high electron temperatures (that are on the order of the Fermi energy). We perform parameter-free density functional theory calculations of the electron temperature-dependent electron-phonon coupling, electronic heat capacities, and thermal conductivities to elucidate the strong role played by the excitation of the low lying