Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong anisotropy of electron-phonon interaction in NbP probed by
  magnetoacoustic quantum oscillations   In this study, we report on the observation of de Haas-van Alphen-type
quantum oscillations (QO) in the ultrasound velocity of NbP as well as `giant
QO' in the ultrasound attenuation in pulsed magnetic fields. The difference of
the QO amplitude for different acoustic modes reveals a strong anisotropy of
the effective deformation potential, which we estimate to be as high as
$9\,\mathrm{eV}$ for certain parts of the Fermi surface. Furthermore, the
natural filtering of QO frequencies and the tracing of the individual Landau
levels to the quantum limit allows for a more detailed investigation of the
Fermi surface of NbP as was previously achieved by means of analyzing QO
observed in magnetization or electrical resistivity.

29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph