Electron-hole compensation effect between topologically trivial electrons and nontrivial holes in NbAs

Via angular Shubnikov-de Haas (SdH) quantum oscillations measurements, we determine the Fermi surface topology of NbAs, a Weyl semimetal candidate. The SdH oscillations consist of two frequencies corresponding to two Fermi surface extrema: 20.8 T ( alpha pocket) and 15.6 T ( beta pocket). The analysis, including a Landau fan plot, shows that the beta pocket has a Berry phase of [Pi] and a small effective mass of ~0.033m0, indicative of a nontrivial topology in momentum space, whereas the alpha pocket has a trivial Berry phase of 0 and a heavier effective mass of ~0.066m0. From the effective mass and the beta -pocket frequency, we determine that the Weyl node is 110.5 meV from the chemical potential. An electron-hole compensation effect is discussed in this system, and its impact on magnetotransport properties is addressed. The difference between NbAs and other monopnictide Weyl semimetals is also discussed.