title: Zeeman-driven Lifshitz transition: a model for the experimentally observed Fermi-surface reconstruction in YbRh2Si2.
abstract: The heavy-fermion metal YbRh(2)Si(2) displays a field-driven quantum phase transition where signatures of a Fermi-surface reconstruction have been identified, often interpreted as a breakdown of the Kondo effect. We argue that instead many properties of the material can be consistently described by assuming a Zeeman-driven Lifshitz transition of narrow heavy-fermion bands. Using a suitable quasiparticle model, we find a smeared jump in the Hall constant and lines of maxima in susceptibility and specific heat, very similar to experimental data. An intermediate non-Fermi-liquid regime emerges due to the small effective Fermi energy near the transition. Further experiments to discriminate the different scenarios are proposed.
authors.affiliation: Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hackl
authors.forename: Matthias
authors.initials: M
authors.lastname: Vojta