Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optically Induced Topological Phase Transition in two dimensional Square
  Lattice Antiferromagnet   The two dimensional square lattice antiferromagnet with spin-orbit coupling
and nonsymmorphic symmetry is recently found to be topological insulator (TI).
We theoretically studied the Floquet states of the antiferromagnetic crystal
with optical irradiation, which could be applicable in opto-spintronic. An
optical irradiation with circular polarization induces topological phase
transition into quantum Anomalous Hall (QAH) phase with varying Chern number.
At the phase boundaries, the Floquet systems could be semimetal with one, two
or three band valleys. A linear polarized optical field induces effective
antiferromagnetic exchange field, which change the phase regime of the TI. At
the intersection of two phase boundaries, the bulk band structure is nearly
flat along one of the high symmetry line in the first Brillouin zone, which
result in large density of states near to the Fermi energy in bulk and
nanoribbons.

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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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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: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: q-bio
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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an