We report the observation of an extreme magnetoresistance (XMR) in HoBi with
a large magnetic moment from Ho f-electrons. Neutron scattering is used to
determine the magnetic wave vectors across several metamagnetic (MM)
transitions on the phase diagram of HoBi. Unlike other magnetic rare-earth
monopnictides, the field dependence of resistivity in HoBi is non-monotonic and
reveals clear signatures of every metamagnetic transition in the
low-temperature and low-field regime, at T < 2 K and H < 2.3 T. The XMR appears
at H > 2.3 T after all the metamagnetic transitions are complete and the system
is spin-polarized by the external magnetic field. The existence of an onset
field for XMR and the intimate connection between magnetism and transport in
HoBi are unprecedented among the magnetic rare-earth monopnictides. Therefore,
HoBi provides a unique opportunity to understand the electrical transport in
magnetic XMR semimetals.
Authors
Yang H-Y; Gaudet J; Aczel AA; Graf DE; Blaha P; Gaulin BD; Tafti F