Possible magnetic-field-induced Lifshitz transition in Ce_1−xLa_xBiPt

Usually the electronic band structure is a rather robust property of the metallic state, especially when applying magnetic fields. For the half-Heusler compounds Ce1−xLaxBiPt, however, we observe magnetic-field-induced band-structure changes in strong magnetic fields. This is evidenced by Shubnikov-de Haas (SdH) and Hall-effect measurements performed in pulsed magnetic fields up to 70 Tesla. Above sample-dependent threshold fields, both in CeBiPt as well as in Ce0.95La0.05BiPt single crystals, the SdH signals vanish and the Hall coefficients change drastically. Such kind of effects are absent in the non-4f compound LaBiPt. Electronic-band-structure calculations can well explain the observed behavior by a 4f-polarization-induced Fermi-surface modification, i.e., a fieldinduced
Lifshitz transition.1,2

1 N. Kozlova et al., Phys. Rev. Lett. 95, 086403 (2005).
2 J. Wosnitza et al., New J. Phys. 8, 174 (2006).