Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unidimensional model of the ad-atom diffusion on a substrate submitted
  to a standing acoustic wave II. Solutions of the ad-atom motion equation   The ad-atom dynamic equation, a Langevin type equation is analyzed and solved
using some non-linear analytical and numerical tools. We noticeably show that
the effect of the surface acoustic wave is to induce an effective potential
that governs the diffusion of the ad-atom: the minima of this effective
potential correspond to the preferential sites in which the ad-atom spends more
time. The strength of this effective potential is compared to the destructuring
role of the thermal diffusion and to the crystalline potential induced by the
substrate.

3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess