Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet
  Cs$_2$CuBr$_4$   We report on high-field electron spin resonance (ESR) studies of magnetic
excitations in the spin-1/2 triangular-lattice antiferromagnet Cs$_2$CuBr$_4$.
Frequency-field diagrams of ESR excitations are measured for different
orientations of magnetic fields up to 25 T. We show that the substantial
zero-field energy gap, $\Delta\approx9.5$ K, observed in the low-temperature
excitation spectrum of Cs$_2$CuBr$_4$ [Zvyagin $et~al.$, Phys. Rev. Lett. 112,
077206 (2014)], is present well above $T_N$. Noticeably, the transition into
the long-range magnetically ordered phase does not significantly affect the
size of the gap, suggesting that even below $T_N$ the high-energy spin dynamics
in Cs$_2$CuBr$_4$ is determined by short-range-order spin correlations. The
experimental data are compared with results of model spin-wave-theory
calculations for spin-1/2 triangle-lattice antiferromagnet.

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The categories of this paper are: eess
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
1
The categories of this paper are: cs
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The categories of this paper are: econ
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an