Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coherent Collisions between Bose-Einstein Condensates   We study the non-degenerate parametric amplifier for matter waves,
implemented by colliding two Bose-Einstein condensates. The coherence of the
amplified waves is shown by observing high contrast interference with a
reference wave and by reversing the amplification process. Since our
experiments also place limits on all known sources of decoherence, we infer
that relative number squeezing is most likely present between the amplified
modes. Finally, we suggest that reversal of the amplification process may be
used to detect relative number squeezing without requiring single-particle
detection.

12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an