Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconductivity phenomenon induced by external in-plane magnetic field
  in (2+1)-dimensional Gross--Neveu type model   Phase structure of the (2+1)-dimensional model with four-fermion interaction
of spin-1/2 quasiparticles (electrons) both in the fermion-antifermion (or
chiral) and fermion-fermion (or superconducting) channels is considered at
nonzero chemical potential $\mu$ and under the influence of an in-plane, i.e.
parallel to a system sheet, external magnetic field $\vec B_\parallel$. It is
shown that at sufficiently large values of $\mu$ and/or $\vec B_\parallel$ the
Cooper pairing (or superconducting) phase appears in the system at arbitrary
relation between coupling constants, provided that there is an (arbitrary
small) attractive interaction in the superconducting channel. In particular, at
sufficiently weak attractive interaction in the chiral channel, the Cooper
pairing occurs even at infinitesimal values of $\mu$ and/or $\vec B_\parallel$.
The superconducting phase of the model is always a paramagnetic one.

9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg