Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anisotropic diffusion in square lattice potentials: giant enhancement
  and control   The unbiased thermal diffusion of an overdamped Brownian particle in a square
lattice potential is considered in the presence of an externally applied ac
driving. The resulting diffusion matrix exhibits two orthogonal eigenvectors
with eigenvalues $D_1>D_2>0$, indicating anisotropic diffusion along a "fast"
and a "slow principal axis". For sufficiently small temperatures, $D_1$ may
become arbitrarily large and at the same time $D_2$ arbitrarily small. The
principal diffusion axis can be made to point into (almost) any direction by
varying either the driving amplitude or the coupling of the particle to the
potential, without changing any other property of the system or the driving.

16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol