title: Verification of the Wiedemann-Franz law in YbRh2Si2 at a quantum critical point.
abstract: The thermal conductivity measurements are performed on the heavy-fermion compound YbRh(2)Si(2) down to 0.04 K and under magnetic fields through a quantum critical point (QCP) at B(c)=0.66  T∥c axis. In the limit as T→0, we find that the Wiedemann-Franz law is satisfied within experimental error at the QCP despite the destruction of the standard signature of Fermi liquid. Our results place strong constraints on models that attempt to describe the nature of the unconventional quantum criticality of YbRh(2)Si(2).
authors.affiliation: Department of Physics, Tokyo Institute of Technology, Meguro 152-8551, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Machida
authors.affiliation: Department of Physics, Tokyo Institute of Technology, Meguro 152-8551, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tomokuni
authors.affiliation: Department of Physics, Tokyo Institute of Technology, Meguro 152-8551, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Izawa
authors.affiliation: SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble, F-38054, France.
authors.forename: G
authors.initials: G
authors.lastname: Lapertot
authors.affiliation: SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble, F-38054, France.
authors.forename: G
authors.initials: G
authors.lastname: Knebel
authors.affiliation: SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble, F-38054, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Brison
authors.affiliation: SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble, F-38054, France.
authors.forename: J
authors.initials: J
authors.lastname: Flouquet