Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The contribution of spin torque to spin Hall coefficient and spin motive
  force in spin-orbit coupling system   We derive rigorously the relativistic angular momentum conservation equation
by means of quantum electrodynamics. The novel nonrelativistic spin current and
torque in the spin-orbit coupling system, up to the order of $1/c^{4}$, are
exactly investigated by using Foldy-Wouthuysen transformation. We find a
perfect spin Hall coefficient including the contribution of spin torque dipole.
A novel spin motive force, analogue to the Lorentz force, is also obtained for
understanding of the spin Hall effect.

23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom