Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-current induced electric field   We theoretically predict that a pure steady state spin-current without
charge-current can induce an electric field. A formula for the induced electric
field is derived and we investigate its characteristics. Conversely, a moving
spin is affected by an external electric field and we present a formula for the
interaction energy.

28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph