Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase transitions in a frustrated biquadratic Heisenberg model with
  coupled orbital degree of freedom for iron-based superconductors   In this work, we study a biquadratic Heisenberg model with coupled orbital
degree of freedom using Monte Carlo simulation in order to investigate the
phase transitions in iron-based superconductors. The antiferro-quadrupolar
state, which may be related to the magnetism of FeSe [Phys. Rev. Lett. 115,
116401 (2015)], is stabilized by the anisotropic biquadratic interaction
induced by a ferro-orbital-ordered state. It is revealed that the orbital and
nematic transitions occur at the same temperature for all the cases, supporting
the mechanism of the orbital-driven nematicity as revealed in most recent
experiments [Nat. Mater. 14, 210 (2015)]. In addition, it is suggested that the
orbital interaction may lead to the separation of the structural and magnetic
phase transitions as observed in many families of iron pnictides.

11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph