Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Density oscillation in highly flattened quantum elliptic rings and
  tunable strong dipole radiation   A narrow elliptic ring containing an electron threaded by a magnetic field B
is studied. When the ring is highly flattened, the increase of B would lead to
a big energy gap between the ground and excited states, and therefore lead to a
strong emission of dipole photons. The photon frequency can be tuned in a wide
range by changing B and/or the shape of the ellipse. The particle density is
found to oscillate from a pattern of distribution to another pattern back and
forth against $B$. This is a new kind of Aharonov-Bohm oscillation originating
from symmetry breaking and is different from the usual oscillation of
persistent current.

25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex