Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Single photons emitted by nano-crystals optically trapped in a deep
  parabolic mirror   We investigate the emission of single photons from CdSe/CdS dot-in-rods which
are optically trapped in the focus of a deep parabolic mirror. Thanks to this
mirror, we are able to image almost the full 4$\pi$ emission pattern of
nanometer-sized elementary dipoles and verify the alignment of the rods within
the optical trap. From the motional dynamics of the emitters in the trap we
infer that the single-photon emission occurs from clusters comprising several
emitters. We demonstrate the optical trapping of rod-shaped quantum emitters in
a configuration suitable for efficiently coupling an ensemble of linear dipoles
with the electromagnetic field in free space.

21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an