Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maltese cross coupling to individual cold atoms in free space   We report on the simultaneous observation from four directions of the
fluorescence of single $^{87}$Rb atoms trapped at the common focus of four high
numerical aperture (${\rm NA}=0.5$) aspheric lenses. We use an
interferometrically-guided pick-and-place technique to precisely and stably
position the lenses along the four cardinal directions with their foci at a
single central point. The geometry gives right angle access to a single quantum
emitter, and will enable new trapping, excitation, and collection methods. The
fluorescence signals indicate both sub-Poissonian atom number statistics and
photon anti-bunching, showing suitability for cold atom quantum optics.

17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph