Quasiparticle properties of a simple metal at high electron temperatures

We compute the real and imaginary parts of the quasiparticle self-energy Sigma due to the electron-electron interaction for electrons and holes in jellium and crystalline Al at electron temperatures approaching the Fermi temperature T-F. Re Sigma and Im Sigma are computed using a finite temperature generalization of the GW approximation. We find a decrease in the electron lifetime and an increase in the valence and conduction bandwidths as T is increased. Calculation of the spectral function A(k,E) reveals that the total weight in the quasiparticle peak is a very weak function of T, and that the basic peak structure remains for Tsimilar tofewx0.1T(F). These predictions suggest that at these electron temperatures, the prominent peak in the absorption spectrum of Al at similar to1.5 eV should be washed out due to lifetime broadening, even if the ions remain in their crystalline positions.