Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Screening of a charged impurity in graphene in a magnetic field   The electron states in the field of a charged impurity in graphene in a
magnetic field are studied numerically. It is shown that a charged impurity
removes the degeneracy of Landau levels converting them into bandlike
structures. As the charge of impurity grows, the repulsion of sublevels of
different Landau levels with the same value of orbital momentum takes place
leading to the redistribution of the wave function profiles of these sublevels
near the impurity. By studying the polarization effects, it is shown in
agreement with the recent experiments that the effective charge of impurity can
be very effectively tuned by chemical potential. If the chemical potential is
situated inside a Landau level, then the charge of impurity is strongly
diminished. In addition, the polarization function in this case has a peak at
zero momentum, which leads to the sign-changing oscillations of the screened
potential as a function of distance. If the chemical potential lies between the
Landau levels, then the screened potential does not change sign, the screening
is minimal, and the charged impurity can strongly affect the electron spectrum.

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The categories of this paper are: physics
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
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The categories of this paper are: math
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol