Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optoelectrical cooling of polar molecules to sub-millikelvin
  temperatures   We demonstrate direct cooling of gaseous formaldehyde (H2CO) to the
microkelvin regime. Our approach, optoelectrical Sisyphus cooling, provides a
simple dissipative cooling method applicable to electrically trapped dipolar
molecules. By reducing the temperature by three orders of magnitude and
increasing the phase-space density by a factor of ~$10^4$ we generate an
ensemble of $3\cdot10^5$ molecules with a temperature of about 420\mu K,
populating a single rotational state with more than 80% purity.

30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin