Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiferroic FeTe$_2$O$_5$Br: Alternating spin chains with frustrated
  interchain interactions   A combination of density functional theory calculations, many-body model
considerations, magnetization and electron spin resonance measurements shows
that the multiferroic FeTe$_2$O$_5$Br should be described as a system of
alternating antiferromagnetic $S=5/2$ chains with strong Fe-O-Te-O-Fe bridges
weakly coupled by two-dimensional frustrated interactions, rather than the
previously reported tetramer models. The peculiar temperature dependence of the
incommensurate magnetic vector can be explained in terms of interchain exchange
striction being responsible for the emergent net electric polarization.

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The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg