Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Probing number squeezing of ultracold atoms across the superfluid-Mott
  insulator transition   The evolution of on-site number fluctuations of ultracold atoms in optical
lattices is experimentally investigated by monitoring the suppression of
spin-changing collisions across the superfluid-Mott insulator transition. For
low atom numbers, corresponding to an average filling factor close to unity,
large on-site number fluctuations are necessary for spin-changing collisions to
occur. The continuous suppression of spin-changing collisions is thus a direct
evidence for the emergence of number-squeezed states. In the Mott insulator
regime, we find that spin-changing collisions are suppressed until a threshold
atom number, consistent with the number where a Mott plateau with
doubly-occupied sites is expected to form.

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The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: q-fin
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph