Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Switching teraherz waves with gate-controlled active graphene
  metamaterials   The extraordinary electronic properties of graphene, such as its continuously
gate-variable ambipolar field effect and the resulting steep change in
resistivity, provided the main thrusts for the rapid advance of graphene
electronics. The gate-controllable electronic properties of graphene provide a
route to efficiently manipulate the interaction of low-energy photons with
massless Dirac fermions, which has recently sparked keen interest in graphene
plasmonics. However, the electro-optic tuning capability of unpatterned
graphene alone is still not strong enough for practical optoelectronic
applications due to its nonresonant Drude-like behaviour. Here, we
experimentally demonstrate that substantial gate-induced persistent switching
and linear modulation of terahertz waves can be achieved in a two-dimensional
artificial material, referred to as a metamaterial, into which an atomically
thin, gated two-dimensional graphene layer is integrated. The gate-controllable
light-matter interaction in the graphene layer can be greatly enhanced by the
strong resonances and the corresponding field enhancement in the metamaterial.
Although the thickness of the embedded single-layer graphene is more than 'six'
orders of magnitude smaller than the wavelength (< {\lambda}/1,000,000), the
one-atom-thick layer, in conjunction with the metamaterial, can modulate both
the amplitude of the transmitted wave by up to 90 per cent and its phase by
more than 40 degrees at room temperature. More interestingly, the
gate-controlled active graphene metamaterials show hysteretic behaviour in the
transmission of terahertz waves, especially when fabricated with multilayer
graphene, which is indicative of persistent photonic memory effects.

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The categories of this paper are: eess
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The categories of this paper are: bayes-an
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
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The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th