Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model of charge and magnetic order formation in itinerant electron
  systems   We propose a simple model of charge and/or magnetic order formation in
systems containing both localized and itinerant electrons coupled by the
on-site, spin-dependent interaction that represents Coulomb repulsion and
Hund's rule (a generalized Falicov-Kimball model). Ground state properties of
the model are analyzed on the square lattice on a basis of the phase diagrams
that have been constructed rigorously, but in a restricted configurational
space. For intermediate values of the coupling constants there are considerable
ranges of itinerant electron densities where phases with complex charge and
magnetic structures of the localized electrons have lower energy than the
simplest antiferro- and ferromagnetic ones. A strong tendency towards the
antiferromagnetic coupling between spins of localized electrons has been
observed close to half-filling for any density of localized electrons,
including situations where the magnetic ions are diluted. For small band
fillings the ferromagnetic coupling between localized spins is predominant.

17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci