Magnetotransport signatures of chiral magnetic anomaly in the half-Heusler phase ScPtBi

Study of the magnetotransport properties of ScPtBi revealed simultaneously (i) a negative contribution to the longitudinal magnetoresistance, (ii) the planar Hall effect, and (iii) distinct angular narrowing of the longitudinal magnetoresistance---three hallmarks of chiral magnetic anomaly (pumping of axial charge between Weyl nodes), a distinct property of topological semimetals. Electronic structure calculations show that structural defects, such as antisites and vacancies, bring a substantial density of states at the Fermi level of ScPtBi, indicating that it is a semimetal, not a zero-gap semiconductor, as predicted earlier. This is in accord with electrical resistivity in ScPtBi, showing no characteristics of a semiconductor. Moreover, below 0.7 K we observed an onset of a superconducting transition, with the resistivity disappearing completely below 0.23 K.