Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconductors as ideal spin sources for spintronics   Spin-polarized transport is investigated in normal metal-superconductor (NS)
junctions as a function of interface transmissivity as well as temperature when
the density of states of a superconductor is Zeeman-split in response to an
exchange field (h_exc). Similarly to the "absolute spin-valve effect" predicted
by D. Huertas-Hernando et al. [Phys. Rev. Lett. 88, 047003 (2002)] in
superconducting proximity structures, we show that NS junctions can be used to
generate highly spin-polarized currents, in alternative to half-metallic
ferromagnets. In particular, the spin-polarized current obtained is largely
tunable in magnitude and sign by acting on bias voltage and h_exc. While for
tunnel contacts the current polarization can be as high as 100%, for
transparent junctions it is dominated by the minority spin species. The effect
can be enhanced by electron "cooling" provided by the superconducting gap.

19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph