Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effect of a Zeeman field on the superconductor-ferromagnet transition in
  metallic grains   We investigate the competition between pairing correlations and
ferromagnetism in small metallic grains in the presence of a Zeeman field. Our
analysis is based on the universal Hamiltonian, valid in the limit of large
Thouless conductance. We show that the coexistence regime of superconducting
and ferromagnetic correlations can be made experimentally accessible by tuning
an external Zeeman field. We compare the exact solution of the model with a
mean-field theory and find that the latter cannot describe pairing correlations
in the intermediate regime. We also study the occurrence of spin jumps across
the phase boundary separating the superconducting and coexistence regimes.

1
The categories of this paper are: cs
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: physics
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con