Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ferroelectricity induced by ferriaxial crystal rotation and spin
  helicity in a B-site-ordered double-perovskite multiferroic In2NiMnO6   We have performed dielectric measurements and neutron diffraction experiments
on the double perovskite In2NiMnO6. A ferroelectric polarization, P ~ 30
{\mu}C/m2, is observed in a polycrystalline sample below TN = 26 K where a
magnetic phase ransition occurs. The neutron diffraction experiment
demonstrates that a complex noncollinear magnetic structure with "cycloidal"
and "proper screw" components appears below TN, which has the incommensurate
propagation vector k = (ka,0,ks; ka ~ 0.274, ks ~ -0.0893). The established
magnetic point group 21' implies that the macroscopic ferroelectric
polarization is along the monoclinic b axis. Recent theories based on the
inverse Dzyaloshinskii-Moriya effect allow us to specify two distinct
contributions to the polarization of In2NiMnO6. One of them is associated with
the cycloidal component, p1 ~ rij x (Si x Sj), and the other with the proper
screw component, p2 ~ [rij (Si x Sj )]A. The latter is explained by coupling
between spin helicity and "ferriaxial" crystal rotation with macroscopic
ferroaxial vector A, characteristic of the B-site ordered perovskite systems
with out-of-plane octahedral tilting.

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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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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: hep-ph
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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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: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg