Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bound states in continuum in an electron waveguide   It is shown that in a double-cavity, two-dimensional electron waveguide, the
interplay between quasi-bound states of each cavity leads to the appearance of
bound states in continuum for certain distances between the cavities. These
bound states may be used to trap electrons in de-localized states distributed
in both cavities.

3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an