Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin superconductor in ferromagnetic graphene   We show a spin superconductor (SSC) in ferromagnetic graphene as the
counterpart to the charge superconductor, in which a spin-polarized
electron-hole pair plays the role of the spin $2 (\hbar/2)$ `Cooper pair' with
a neutral charge. We present a BCS-type theory for the SSC. With the
`London-type equations' of the super-spin-current density, we show the
existence of an electric `Meissner effect' against a spatial varying electric
field. We further study a SSC/normal conductor/SSC junction and predict a
spin-current Josephson effect.

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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
2
The categories of this paper are: math
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The categories of this paper are: econ
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics