title: Quasiparticle relaxation dynamics in heavy fermion compounds.
abstract: We present the first femtosecond studies of electron-phonon (e-ph) thermalization in heavy-fermion compounds. The e-ph thermalization time tau(ep) increases below the Kondo temperature by more than 2 orders of magnitude as T=0 K is approached. Analysis using the two-temperature model and numerical simulations based on Boltzmann's equations suggest that this anomalous slowing down of the e-ph thermalization derives from the large electronic specific heat and the suppression of scattering between heavy electrons and phonons.
authors.affiliation: Los Alamos National Laboratory, Mail Stop K764, Los Alamos, New Mexico 87545, USA.
authors.forename: J
authors.initials: J
authors.lastname: Demsar
authors.forename: R D
authors.initials: RD
authors.lastname: Averitt
authors.forename: K H
authors.initials: KH
authors.lastname: Ahn
authors.forename: M J
authors.initials: MJ
authors.lastname: Graf
authors.forename: S A
authors.initials: SA
authors.lastname: Trugman
authors.forename: V V
authors.initials: VV
authors.lastname: Kabanov
authors.forename: J L
authors.initials: JL
authors.lastname: Sarrao
authors.forename: A J
authors.initials: AJ
authors.lastname: Taylor