  The noncentrosymmetric Half Heusler compound YPtBi exhibits superconductivity
below a critical temperature T_c = 0.77 K with a zero-temperature upper
critical field H_c2(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 x
10^18 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.
