Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Critical and multicritical behavior in the Ising-Heisenberg universality
  class   Critical behavior of three-dimensional classical frustrated antiferromagnets
with a collinear spin ordering and with an additional twofold degeneracy of the
ground state is studied. We consider two lattice models, whose continuous limit
describes a single phase transition with a symmetry class differing from the
class of non-frustrated magnets as well as from the classes of magnets with
non-collinear spin ordering. A symmetry breaking is described by a pair of
independent order parameters, which are similar to order parameters of the
Ising and O(N) models correspondingly. Using the renormalization group method,
it is shown that a transition is of first order for non-Ising spins. For Ising
spins, a second order phase transition from the universality class of the O(2)
model may be observed. The lattice models are considered by Monte Carlo
simulations based on the Wang-Landau algorithm. The models are a ferromagnet on
a body-centered cubic lattice with the additional antiferromagnetic exchange
interaction between next-nearest-neighbor spins and an antiferromagnet on a
simple cubic lattice with the additional interaction in layers. We consider the
cases N=1,2,3 and in all of them find a first-order transition. For the N=1
case we exclude possibilities of the second order or pseudo-first order of a
transition. An almost second order transition for large N is also discussed.

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The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th