Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Josephson Current through a correlated quantum level: Andreev states and
  Pi-junction behavior   The Josephson transport and the electronic properties of a quantum dot
characterized by a single level coupled to superconducting leads is analyzed.
Different approximations are used and compared: the mean field approximation,
the second order perturbation theory in the Coulomb interaction and the exact
diagonalization in the zero band-width limit. The system exhibits a rich
behavior as a function of the relevant parameters. We discuss in detail the
conditions for the observation of Pi-junction behavior and the effect of
Coulomb interactions on the Andreev states.

29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin