Unusual magnetotransport and surface Dirac-cone state in single-crystalline Pt 3 Te 4 : a new candidate of Dirac semimetal

Abstract Exotic magnetotransport and magnetization properties of Pt3Te4 single crystals were investigated to probe the topological properties of the Pt3Te4 semimetal. Pt3Te4 reveals a strongly correlated electronic feature as well as a non-trivial magnetoresistance (MR) characteristic. The signature of helical spin texture from the topological surface state and the chiral anomaly associated with a linear-like energy dispersion of electronic states were detected. At low temperatures, the negative longitudinal magnetoresistance in the low-field region could be explained with the transport formula containing the chiral-anomaly effect as well as the weak antilocalization transport. Moreover, the high-field transverse magnetoresistance at temperatures below 60 K showed a non-saturating linear-like behavior, which was examined with the theory of Abrikosov’s quantum MR, indicating a Dirac-cone-like dispersion in Pt3Te4 at low temperatures. This work reveals the drastic impact of the concept that the magnetotransport in Pt3Te4 can be dominated by the surface electrons in a Dirac fermion state, thus inferring that Pt3Te4 is a new candidate of Dirac semimetal.