Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonconservative dipole forces in a two-atom system with one atom excited   We compute the nonconservative electric dipole forces between two atoms, one
of which is initially excited. These forces derive from the time variation of
the longitudinal electromagnetic momentum. In contrast to the conservative
van-der-Waals forces, the nonconservative forces posses components orthogonal
to the interatomic axis. Thus, despite being several orders of magnitude
smaller than van-der-Waals', they might be accessible experimentally for the
case of two identical atoms. In addition, as with the van-der-Waals forces, the
nonconservative forces present nonreciprocal constituents which result in a net
force on the two-atom system. We offer an estimate of the spatial displacement
caused by the nonconservative forces on a binary system of Hydrogen atoms.

1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn