Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Impurity states of electrons on the surface of a nanotube in a magnetic
  field   The localization of electrons in the field of isolated nonmagnetic impurity
atoms on the surface of a nanotube in a magnetic field is considered. A model
of a Gaussian separable impurity potential capable of localizing an electron at
any intensity is used. The positions of the local level are found in the regime
of strong and weak localizations. The positions of the resonances are found,
their widths are estimated. They experience Aharonov-Bohm oscillations when the
magnetic flux in the tube changes. It is shown that the positions of the
resonances experience oscillations similar to the de Haas-van Alphen
oscillations, which are not associated with a magnetic field.

17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga