ELECTRON-ELECTRON SCATTERING IN SIMPLE METALS

The interaction between two-electron quasiparticles is approximated in terms of the dielectric and vertex functions of the uniform electron gas. These functions must satisfy the compressibility sum rule, and this fact makes the interaction at metallic densities much stronger than the Thomas-Fermi screened Coulomb interaction. A problem arises in applying this theory to real metals because the compressibility of the electron gas at densities appropriate to rubidium and cesium is negative. This anomaly is removed by taking into account the real metal effect of core polarization. The effective interaction is used to calculate the electron-electron scattering rate and its contribution to the thermal resistivity. The result is consistent with the single experimental measurement presently available on sodium (new results on potassium, rubidium, and cesium became available after this paper was completed; these are reported in Table III), whereas the Thomas-Fermi interaction predicts a thermal resistivity that is too small by a factor of 7. The scattering rates and thermal resistivities of all the alkali metals are calculated to enable comparison with future experimental values. © 1979 The American Physical Society.