title: Magnetic-field induced quantum critical point in YbRh(2)Si(2).
abstract: We report low-temperature calorimetric, magnetic, and resistivity measurements on the antiferromagnetic (AF) heavy-fermion metal YbRh(2)Si(2) ( T(N)=70 mK) as a function of magnetic field B. While for fields exceeding the critical value B(c0) at which T(N)-->0 the low-temperature resistivity shows an AT2 dependence, a 1/(B-B(c0)) divergence of A(B) upon reducing B to B(c0) suggests singular scattering at the whole Fermi surface and a divergence of the heavy quasiparticle mass. The observations are interpreted in terms of a new type of quantum critical point separating a weakly AF ordered from a weakly polarized heavy Landau-Fermi liquid state.
authors.affiliation: Max-Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Gegenwart
authors.forename: J
authors.initials: J
authors.lastname: Custers
authors.forename: C
authors.initials: C
authors.lastname: Geibel
authors.forename: K
authors.initials: K
authors.lastname: Neumaier
authors.forename: T
authors.initials: T
authors.lastname: Tayama
authors.forename: K
authors.initials: K
authors.lastname: Tenya
authors.forename: O
authors.initials: O
authors.lastname: Trovarelli
authors.forename: F
authors.initials: F
authors.lastname: Steglich