Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Light emitting diodes of inverse spin valves   We propose making light emitting diodes out of inverse spin valves. The
proposed diodes rely on the spin-dependent electron transport of inverse spin
valves that are layered structures of a ferromagnetic half-metal sandwiched
between two non-magnetic metals. Under a bias, a giant spin-dependent chemical
potential difference between spin-up and spin-down electrons is created. Thus,
the inverse spin valves are possible to emit light when electrons in higher
chemical potential go to the lower chemical potential. The advantages of this
type of light emitting diodes include tunableness and less demand on materials.

12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con