Magnetotransport properties of the triply degenerate node topological semimetal tungsten carbide

摘要

We report the magnetoresistance (MR), Hall effect, and de Haas-van Alphen(dHvA) effect studies of the single crystals of tungsten carbide, WC, which ispredicted to be a new type of topological semimetal with triply degeneratenodes. With the magnetic field rotated in the plane perpendicular to thecurrent, WC shows field induced metal to insulator like transition and largenonsaturating quadratic MR at low temperature. As the magnetic field parallelto the current, a pronounced negative longitudinal MR only can be observed whenthe current flows along the certain direction. Hall effect indicates WC is aperfect compensated semimetal, which may be related to the large nonsaturatingquadratic MR. The analysis of dHvA oscillations reveals that WC is a multibandsystem with small cross-sectional areas of Fermi surface and light cyclotroneffective masses. Our results indicate that WC is an ideal platform to studythe recently proposed New Fermions with triply degenerate crossing points.