title: Energy dependence of quasiparticle relaxation in a disordered fermi liquid.
abstract: A spectroscopic method is applied to measure the inelastic quasiparticle relaxation rate in a disordered Fermi liquid. The quasiparticle relaxation rate gamma is deduced from the magnitude of fluctuations in the local density of states, which are probed using resonant tunneling through a localized impurity state. We study its dependence on the excitation energy E measured from the Fermi level. In a disordered metal (heavily doped GaAs) we find that gamma~E3/2 within the experimentally accessible energy interval, in agreement with the Altshuler-Aronov theory for electron-electron interactions in diffusive conductors.
authors.affiliation: Institut für Festköperphysik, Universität Hannover, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Schmidt
authors.forename: P
authors.initials: P
authors.lastname: König
authors.forename: E
authors.initials: E
authors.lastname: McCann
authors.forename: V I
authors.initials: VI
authors.lastname: Fal'ko
authors.forename: R J
authors.initials: RJ
authors.lastname: Haug