Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Nonlinear Optics with a Germanium-Vacancy Color Center in a
  Nanoscale Diamond Waveguide   We demonstrate a quantum nanophotonics platform based on germanium-vacancy
(GeV) color centers in fiber-coupled diamond nanophotonic waveguides. We show
that GeV optical transitions have a high quantum efficiency and are nearly
lifetime-broadened in such nanophotonic structures. These properties yield an
efficient interface between waveguide photons and a single GeV without the use
of a cavity or slow-light waveguide. As a result, a single GeV center reduces
waveguide transmission by $18 \pm 1\%$ on resonance in a single pass. We use a
nanophotonic interferometer to perform homodyne detection of GeV resonance
fluorescence. By probing the photon statistics of the output field, we
demonstrate that the GeV-waveguide system is nonlinear at the single-photon
level.

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The categories of this paper are: astro-ph
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The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
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The categories of this paper are: hep-th
1
The categories of this paper are: cs
19
The categories of this paper are: eess
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph