Superconductivity and Shubnikov–de Haas oscillations in the noncentrosymmetric half-Heusler compound YPtBi

Recent findings of possible topological superconductivity in YPtBi motivated us to grow and investigate single crystals of this material. The compound was studied by means of ac magnetic susceptibility, electrical resistivity, Hall resistivity, and heat capacity measurements, performed in wide ranges of temperature and magnetic field. The superconductivity below the critical temperature Tc=0.970.28em0exK was clearly reflected in the magnetic and electronic transport data. The upper critical field Bc2 was estimated at 1.84 T. However, no obvious anomaly near Tc was found in the temperature dependence of the heat capacity. In the normal state YPtBi appears semimetallic but its electrical conductance can be described by two components corresponding to parallel channels: metallic and semiconducting, with the latter becoming negligible at temperatures below 40 K. Shubnikov--de Haas oscillations were observed at temperatures below 10 K. Nontrivial Berry phase together with weak antilocalization effect strongly support the presence of Dirac fermions in YPtBi.