Magnetic and superconducting phase diagram of the half-Heusler topological semimetal HoPdBi

Abstract

We report a study of the magnetic and electronic properties of the non-centrosymmetric half-Heusler antiferromagnet HoPdBi ( K). Magnetotransport measurements show HoPdBi has a semimetallic behavior with a carrier concentration extracted from the Shubnikov–de Haas effect. The magnetic phase diagram in the field-temperature plane has been determined by transport, magnetization, and thermal expansion measurements: magnetic order is suppressed at T for . Superconductivity with K is found in the antiferromagnetic phase. Ac-susceptibility measurements provide solid evidence for bulk superconductivity below K with a screening signal close to a volume fraction of 100%. The upper critical field shows an unusual linear temperature variation with T. We also report electronic structure calculations that classify HoPdBi as a new topological semimetal, with a non-trivial band inversion of 0.25 eV.