Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum phase diagram of $J_1-J_2$ Heisenberg $S=1/2$ antiferromagnet in
  honeycomb lattice: a modified spin wave study   Using modified spin wave (MSW) method, we study the $J_1-J_2$ Heisenberg
model with first and second neighbor antiferromagnetic exchange interactions.
For symmetric $S=1/2$ model, with the same couplings for all the equivalent
neighbors, we find three phase in terms of frustration parameter
${\bar\alpha=J_2/J_1}$: (1) a commensurate collinear ordering with staggered
magnetization (N{\'e}el.I state) for $0\leq{\bar\alpha}\lesssim 0.207$ , (2) a
magnetically gapped disordered state for $0.207\lesssim{\bar\alpha}\lesssim
0.369$, preserving all the symmetries of the Hamiltonian and lattice, hence by
definition is a quantum spin liquid (QSL) state and (3) a commensurate
collinear ordering in which two out of three nearest neighbor magnetizations
are antiparallel and the remaining pair are parallel (N{\'e}el.II state), for
$0.396\lesssim{\bar\alpha}\leq 1$. We also explore the phase diagram of
distorted $J_1-J_2$ model with $S=1/2$. Distortion is introduced as an
inequality of one nearest neighbor coupling with the other two. This yields a
richer phase diagram by the appearance of a new gapped QSL, a gapless QSL and
also a valence bond crystal (VBC) phase in addition to the previously three
phases found for undistorted model.

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The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
3
The categories of this paper are: physics
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The categories of this paper are: stat
2
The categories of this paper are: math
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The categories of this paper are: econ
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The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-th