Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cold Atoms and Creation of New States of Matter: Bose-Einstein
  Condensates, Kapitza States, and '2D Magnetic Hydrogen Atoms'   We have succeded in creating Bose-Einstein condensates with 2 million sodium
atoms in a '4D' magnetic trap. We show the dynamic formation of a condensate as
evaporative cooling proceeds. We also present a series of trap-release pictures
clearly showing the distinctly different modes of expansion of condensate and
thermal cloud. We further give two examples of wave guides for atomic de
Broglie matter waves. One structure, the Kapitza wave guide, uses the
interaction between an electrically polarizable atom and a charged wire. For
stably bound orbits, a dynamical stabilization with time dependent potentials
is necessary. This system, which can be tuned freely between classical and
quantum regimes, shows chaotic behavior in the classical limit. The static
counterpart of this wave guide leads to the introduction of the 'angular
momentum quantum ladder' . The second wave guide structure is based upon the
interaction between a current carrying wire and the magnetic dipole moment of
an atom. A hydrogenic spectrum of bound states is derived through the concept
of supersymmetry.

10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat