Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microscopic Theory of Magnetic Phase Transitions in HoNi_2B_2C   We present a microscopic theory for the low temperature metamagnetic phase
diagram of HoNi_2B_2C that agrees well with experiments.For the same model we
determined the zero field ground state as a function of temperature and find
the $c$-axis commensurate to incommensurate transition in the expected
temperature range. The complex behaviour of the system originates from the
competition between the crystalline electric field and the
Ruderman-Kittel-Kasuya-Yosida interaction, whose effective form is obtained. No
essential influence of superconductivity has to be invoked to understand the
magnetic phase diagram of this material.

31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas