Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Switching between different vortex states in 2-dimensional easy-plane
  magnets due to an ac magnetic field   Using a discrete model of 2-dimensional easy-plane classical ferromagnets, we
propose that a rotating magnetic field in the easy plane can switch a vortex
from one polarization to the opposite one if the amplitude exceeds a threshold
value, but the backward process does not occur. Such switches are indeed
observed in computer simulations.

28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th