Magnetic-Field Dependence of the YbRh2Si2 Fermi Surface
  Magnetic-field-induced changes of the Fermi surface play a central role in theories of the exotic quantum criticality of YbRh2Si2. We have carried out de Haas-van Alphen measurements in the magnetic-field range 8 T <= H <= 16 T, and directly observe field dependence of the extremal Fermi surface areas. Our data support the theory that a low-field "large" Fermi surface, including the Yb 4f quasihole, is increasingly spin split until a majority-spin branch undergoes a Lifshitz transition and disappears at H0 ~ 10 T, without requiring 4f localization at H0. 
P.M.C. Rourke (1), A. McCollam (1), G. Lapertot (2), G. Knebel (2), J.   Flouquet (2) and S.R. Julian (1) ((1) Department of...