Bulk Fermi surface of the Weyl type-II semimetallic candidate NbIrTe₄

Recently, a new group of layered transition-metal tetra-chalcogenides was proposed via first-principles calculations to correspond to a new family of Weyl type-II semimetals with promising topological properties in the bulk as well as in the monolayer limit. In this paper, we present measurements of the Shubnikov-de Haas (SdH) and de Haas-van Alphen effects under high magnetic fields for the type-II Weyl semimetallic candidate NbIrTe₄.We find that the angular dependence of the observed Fermi surface extremal cross-sectional areas agree well with our density functional theory (DFT) calculations supporting the existence ofWeyl type-II points in this material. Although we observe a large and nonsaturating magnetoresistivity in NbIrTe₄ under fields all the way up to 35 T, Hall-effect measurements indicate that NbIrTe₄ is not a compensated semimetal. The transverse magnetoresistivity displays a fourfold angular dependence akin to the so-called butterfly magnetoresistivity observed in nodal line semimetals. Finally, we conclude that the magnetoresistivity and its unconventional angular dependence are governed by the topography of the Fermi surface and the resulting anisotropy in effective masses and in carrier mobilities.