Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spontaneous trimerization in a bilinear-biquadratic S=1 zig-zag chain   Recent theoretical studies raised the possibility of a realization of spin
nematic states in the S=1 triangular lattice compound NiGa_2S_4. We study the
bilinear-biquadratic spin 1 chain in a zig-zag geometry by means of the density
matrix renormalization group method and exact diagonalization. We present the
phase diagram focusing on antiferromagnetic interactions. Adjacent to the known
Haldane-double Haldane and the extended critical phase with dominant spin
nematic correlations we find a trimerized phase with a nonvanishing energy gap.
We discuss results for different order parameters, energy gaps, correlation
functions, and the central charge, and make connection to field theoretical
predictions for the phase diagram.

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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph