Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Purcell-enhanced single-photon emission from nitrogen-vacancy centers
  coupled to a tunable microcavity   Optical microcavities are a powerful tool to enhance spontaneous emission of
individual quantum emitters. However, the broad emission spectra encountered in
the solid state at room temperature limit the influence of a cavity, and call
for ultra-small mode volume. We demonstrate Purcell-enhanced single photon
emission from nitrogen-vacancy (NV) centers in nanodiamonds coupled to a
tunable fiber-based microcavity with a mode volume down to $1.0\,\lambda^{3}$.
We record cavity-enhanced fluorescence images and study several single emitters
with one cavity. The Purcell effect is evidenced by enhanced fluorescence
collection, as well as tunable fluorescence lifetime modification, and we infer
an effective Purcell factor of up to 2.0. With numerical simulations, we
furthermore show that a novel regime for light confinement can be achieved,
where a Fabry-Perot mode is combined with additional mode confinement by the
nanocrystal itself. In this regime, effective Purcell factors of up to 11 for
NV centers and 63 for silicon vacancy centers are feasible, holding promise for
bright single photon sources and efficient spin readout under ambient
conditions.

9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin