Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin dephasing and photoinduced spin diffusion in high-mobility
  110-grown GaAs-AlGaAs two-dimensional electron systems   We have studied spin dephasing and spin diffusion in a high-mobility
two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown
in the [110] direction, by a two-beam Hanle experiment. For very low excitation
density, we observe spin lifetimes of more than 16 ns, which rapidly decrease
as the pump intensity is increased. Two mechanisms contribute to this decrease:
the optical excitation produces holes, which lead to a decay of electron spin
via the Bir-Aranov-Pikus mechanism and recombination with spin-polarized
electrons. By scanning the distance between the pump and probe beams, we
observe the diffusion of spin-polarized electrons over more than 20 microns.
For high pump intensity, the spin polarization in a distance of several microns
from the pump beam is larger than at the pump spot, due to the reduced
influence of photogenerated holes.

1
The categories of this paper are: cs
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas