Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unusual thermal Hall effect in a Kitaev spin liquid candidate
  $\alpha$-RuCl$_3$   The Kitaev quantum spin liquid displays the fractionalization of quantum
spins into Majorana fermions. The emergent Majorana edge current is predicted
to manifest itself in the form of a finite thermal Hall effect, a feature
commonly discussed in topological superconductors. Here we report on thermal
Hall conductivity $\kappa_{xy}$ measurements in $\alpha$-RuCl$_3$, a candidate
Kitaev magnet with the two-dimensional honeycomb lattice. In a spin-liquid
(Kitaev paramagnetic) state below the temperature characterized by the Kitaev
interaction $J_K/k_B \sim 80$ K, positive $\kappa_{xy}$ develops gradually upon
cooling, demonstrating the presence of highly unusual itinerant excitations.
Although the zero-temperature property is masked by the magnetic ordering at
$T_N=7$ K, the sign, magnitude, and $T$-dependence of $\kappa_{xy}/T$ at
intermediate temperatures follows the predicted trend of the itinerant Majorana
excitations.

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The categories of this paper are: nlin
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: plasm-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an