Density response to short-pulse excitation in gold

We investigate the dynamics of band occupation in gold after excitation with short laser pulses. Strong non‐equilibrium distributions can be created by intra‐ and inter‐band transitions driven by the absorption of photons with different wavelengths. First, we briefly discuss how photons can be used as a probe and how electrons with non‐Fermi distributions can be described. Then we focus on the relaxation stage where a temperature has been established but the occupation numbers in the different bands are not yet in equilibrium with this newly established elevated temperature. We describe the relaxation towards a system with a common chemical potential with rate equations that also include the energy transfer to the lattice or ions. Finally, we give an outlook on the optical response of the relaxing electron system to a probe pulse of radiation