Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Crossover between fast and slow excitation of magnetization by spin
  torque   A crossover between two mechanisms destabilizing the magnetization in
equilibrium by the spin transfer effect is found in a ferromagnetic multilayer
consisting of an in-plane magnetized free layer and a perpendicularly
magnetized pinned layer, where an in-plane magnetic field is applied, and
electric current flows from the pinned to the free layer. A fast transition
from the in-plane to the out-of-plane state occurs in the low-field region,
whereas a slow transition with small-amplitude oscillation becomes dominant in
the high-field region. On the other hand, only the fast transition mechanism
appears for the opposite current direction.

16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph