Specifics of d-metals (Au) emission in case of non-equilibrium heating of electrons and lattice with femtosecond laser pulses

The paper refers to the mechanisms of emission of noble metals taking into account the specifics associated with the two-temperature state of matter. The emission is caused by the action of an ultrashort infrared laser pulse. It is shown that the two-temperature state results in two effects contributing to the radiated emission of hot electrons. The first effect is interband radiative recombination of electrons induced by thermal smearing of the Fermi distribution of conduction-band electrons. The second effect is radiation of hot conduction-band electrons in case of inelastic electron-phonon interaction. This effect is due to the fact that thermal smearing of the Fermi distribution of conduction-band electrons, taking into account the electron-phonon interaction, and in the presence of strong near fields, enables intraband radiative transitions for electrons in the sp-band.