Inelastic lifetimes of hot electrons in real metals

We report a first-principles description of inelastic lifetimes of excited electrons in real Cu and Al, which we compute, within the GW approximation of many-body theory, from the knowledge of the self-energy of the excited q uasiparticle. Our full band-structure calculations indicate that actual lif etimes are the result of a delicate balance between localization, density o f states, screening, and Fermi-surface topology. A major contribution from d electrons participating in the screening of electron-electron interaction s yields lifetimes of excited electrons in copper that are larger than thes e of electrons in a free-electron gas with the electron density equal to th at of valence (4s(l)) electrons. In aluminum, a simple metal with no d band s, splitting of the band structure over the Fermi level results in electron lifetimes that are smaller than those of electrons in a free-electron gas.