Magnetic torque of holmium antimonide topological semimetal

The family of compounds AX, where A = Lanthanides or Actinides and X = pnictides, have drawn a great scientific interest recently due to their unusual magneto-transport properties and potential non-trivial nature of the topological ground state. HoSb in one of the candidates of this family that shows antiferromagnetic transition at 5.7 K. Our recent magneto-transport and ARPES studies indicate the presence of the Rashba-type surface-states and non-trivial semimetallic characteristics in this material. In non-trivial magnetic semimetals it is important to understand the interplay between topology and magnetism. In HoSb, however, this behavior is still not well-understood. In order to account for this issue, we have initiated detailed studies of magnetic torque of HoSb along the three crystallographic directions, and in the antiferromagnetic and paramagnetic phases. We show that in this cubic system the torque exhibits large magnetic anisotropy in antiferromagnetic phase and an angle dependence indicates the presence of complex magnetic structure below the Neel temperature. We will discuss implications of these studies in the context of the presence of non-trivial topological state in this material.