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

22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an