Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Core-Shell Structured Dielectric-Metal Circular Nanodisk Antenna: Gap
  Plasmon Assisted Magnetic Toroid-like Cavity Modes   Plasmonic nanoantennas, the properties of which are essentially determined by
their resonance modes, are of interest both fundamentally and for various
applications. Antennas with various shapes, geometries and compositions have
been demonstrated, each possessing unique properties and potential
applications. Here, we propose the use of a sidewall coating as an additional
degree of freedom to manipulate plasmonic gap cavity modes in strongly coupled
metallic nanodisks. It is demonstrated that for a dielectric middle layer with
a thickness of a few tens of nanometers and a sidewall plasmonic coating of
more than ten nanometers, the usual optical magnetic resonance modes are
eliminated, and only magnetic toroid-like modes are sustainable in the infrared
and visible regime. All of these deep-subwavelength modes can be interpreted as
an interference effect from the gap surface plasmon polaritons. Our results
will be useful in nanoantenna design, high-Q cavity sensing, structured
light-beam generation, and photon emission engineering.

7
The categories of this paper are: hep-th
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The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
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The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
1
The categories of this paper are: cs
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The categories of this paper are: quant-ph
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The categories of this paper are: eess