Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Creation of matter wave Bessel beams   Bessel beams are plane waves with amplitude profiles described by Bessel
functions. They are important because of their property of limited diffraction
and their capacity to carry orbital angular momentum. Here we report the
creation of a Bessel beam of de Broglie matter waves. The Bessel beam is
produced by the free evolution of a thin toroidal atomic Bose-Einstein
condensate (BEC) which has been set into rotational motion. By attempting to
stir it at different rotation rates, we show that the toroidal BEC can only be
made to rotate at discrete, equally-spaced frequencies, demonstrating that
circulation is quantized in atomic BECs. The method used here to generate
matter wave Bessel beams with a Painted Potential can be viewed as a form of
wavefunction engineering which might be extended to implement arbitrary cold
atom matter wave holography.

34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
21
The categories of this paper are: adap-org