title: Evolution of the Kondo state of YbRh2Si2 probed by high-field ESR.
abstract: An electron spin resonance (ESR) study of the heavy fermion compound YbRh2Si2 for fields up to approximately 8 T reveals a strongly anisotropic signal in the Kondo state below approximately 25 K. A similarity between the T dependence of the ESR parameters and that of the specific heat and the 29Si nuclear magnetic resonance data gives evidence that the ESR response is given by heavy fermions. Tuning the Kondo effect on the 4f states with magnetic fields approximately 2-8 T and temperature 2-25 K yields a gradual change of the ESR g factor and linewidth which reflects the evolution of the Kondo state in this Kondo lattice system.
authors.affiliation: IFW Dresden, Institute for Solid State Research, Post Office Box 270116, D-01171 Dresden, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Schaufuss
authors.forename: V
authors.initials: V
authors.lastname: Kataev
authors.forename: A A
authors.initials: AA
authors.lastname: Zvyagin
authors.forename: B
authors.initials: B
authors.lastname: Büchner
authors.forename: J
authors.initials: J
authors.lastname: Sichelschmidt
authors.forename: J
authors.initials: J
authors.lastname: Wykhoff
authors.forename: C
authors.initials: C
authors.lastname: Krellner
authors.forename: C
authors.initials: C
authors.lastname: Geibel
authors.forename: F
authors.initials: F
authors.lastname: Steglich