Superconductivity in the topological semimetal YPtBi

The noncentrosymmetric half Heusler compound YPtBi exhibits superconductivity below a critical temperature Tc=0.77 K with a zero-temperature upper critical field Hc2(0)=1.5 T. Magnetoresistance and Hall measurements support theoretical predictions that this material is a topologically nontrivial semimetal having a surprisingly low positive charge-carrier density of 2×10¹⁸ cm^-3. Unconventional linear magnetoresistance and beating in Shubnikov--de Haas oscillations point to spin-orbit split Fermi surfaces. The sensitivity of magnetoresistance to surface roughness suggests a possible contribution from surface states. The combination of noncentrosymmetry and strong spin-orbit coupling in YPtBi presents a promising platform for the investigation of topological superconductivity.