Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Twisted Magnon Frequency Comb and Penrose Superradiance   Quantization effects of the nonlinear magnon-vortex interaction in
ferromagnetic nanodisks are studied. We show that the circular geometry twists
the spin-wave fields with spiral phase dislocations carrying quantized orbital
angular momentum (OAM). Meanwhile, the confluence and splitting scattering of
twisted magnons off the gyrating vortex core (VC) generates a frequency comb
consisting of discrete and equally spaced spectral lines, dubbed as twisted
magnon frequency comb (tMFC). It is found that the mode spacing of the tMFC is
equal to the gyration frequency of the VC and the OAM quantum numbers between
adjacent spectral lines differ by one. By applying a magnetic field
perpendicular to the plane of a thick nanodisk, we observe a magnonic Penrose
superradiance inside the cone vortex state, which mimics the amplification of
waves scattered from a rotating black hole. It is demonstrated that the
higher-order modes of tMFC are significantly amplified while the lower-order
ones are trapped within the VC gyrating orbit which manifests as the
ergoregion. These results suggest a promising way to generate twisted magnons
with large OAM and to drastically improve the flatness of the magnon comb.

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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: acc-phys