Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin waves and revised crystal structure of honeycomb iridate Na2IrO3   We report inelastic neutron scattering measurements on Na2IrO3, a candidate
for the Kitaev spin model on the honeycomb lattice. We observe spin-wave
excitations below 5 meV with a dispersion that can be accounted for by
including substantial further-neighbor exchanges that stabilize zig-zag
magnetic order. The onset of long-range magnetic order below 15.3 K is
confirmed via the observation of oscillations in zero-field muon-spin rotation
experiments. Combining single-crystal diffraction and density functional
calculations we propose a revised crystal structure model with significant
departures from the ideal 90 deg Ir-O-Ir bonds required for dominant Kitaev
exchange.

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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: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys