Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generating squeezed vacuum field with non-zero orbital angular momentum
  with atomic ensembles   We demonstrated that by using a pump field with non-zero orbital angular
momentum (OAM) in the polarization self-rotation squeezing process it is
possible to generate a squeezed vacuum optical field with the matching OAM. We
found a similar level of maximum quantum noise reduction for a first-order
Laguerre-Gaussian pump beam and a regular Gaussian pump beam, even though the
optimal operational conditions differed in these two cases. Also, we
investigated the effect of self-defocusing on the level of the vacuum squeezing
by simultaneously monitoring the minimum quantum noise level and the output
beam transverse profile at various pump laser powers and atomic densities, and
found no direct correlations between the increased beam size and the degree of
measured squeezing.

23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
19
The categories of this paper are: eess