Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Current-induced spin polarization in InGaAs and GaAs epilayers with
  varying doping densities   The current-induced spin polarization and momentum-dependent spin-orbit field
were measured in In$_{x}$Ga$_{1-x}$As epilayers with varying indium
concentrations and silicon doping densities. Samples with higher indium
concentrations and carrier concentrations and lower mobilities were found to
have larger electrical spin generation efficiencies. Furthermore,
current-induced spin polarization was detected in GaAs epilayers despite the
absence of measurable spin-orbit fields, indicating that the extrinsic
contributions to the spin polarization mechanism must be considered.
Theoretical calculations based on a model that includes extrinsic contributions
to the spin dephasing and the spin Hall effect, in addition to the intrinsic
Rashba and Dresselhaus spin-orbit coupling, are found to qualitatively agree
with the experimental results.

23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph