Weyl Nodes Close to the Fermi Energy in NbAs

The noncentrosymmetric transition metal monopnictides NbP, TaP, NbAs and TaAs are a family of Weyl semimetals in which pairs protected linear crossings spin-resolved bands occur. These so-called nodes characterized by integer topological charges opposite sign associated with singular points Berry curvature momentum space. In such system anomalous magnetoelectric responses predicted, should only occur if the crossing close to Fermi level enclosed surface pockets penetrated an flux curvature, dubbed pockets. was shown possess whereas TaP NbP have trivial enclosing zero net curvature. Here, via measurements magnetic torque, resistivity magnetisation, we present comprehensive quantum oscillation study NbAs, last member this where precise shape nature is still unknown. We detect six distinct frequency branches, two not been observed before. A comparison density functional theory calculations suggests that largest topologically trivial, low frequencies might stem from tiny within few meV energy.