Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical model for the superconducting and magnetically ordered
  borocarbides   We present a theory of superconductivity in presence of a general magnetic
structure in a form suitable for the description of complex magnetic phases
encountered in borocarbides. The theory, complemented with some details of the
band structure and with the magnetic phase diagram, may explain the nearly
reentrant behaviour and the anisotropy of the upper critical field of HoNi2B2C.
The onset of the helical magnetic order depresses superconductivity via the
reduction of the interaction between phonons and electrons caused by the
formation of magnetic Bloch states. At mean field level, no additional
suppression of superconductivity is introduced by the incommensurability of the
helical phase.

8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin