Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fiber-coupled pillar array as a highly pure and stable single-photon
  source   A highly pure and stable single-photon source is prepared that comprises a
well-designed pillar array in which each pillar contains only a few InAs
quantum dots. A nano-pillar in this array is in direct contact with a fiber end
surface and cooled in a liquid-He bath. Auto-correlation measurement shows that
this source provides an average $g^{(2)}(0)$ value of 0.0174 in the measured
excitation-power range. This photon source and fiber coupling are quite rigid
against external disturbances such as cooling-heating cycles and vibration,
with long-term stability.

16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol