Spin superconductor in ferromagnetic graphene

We show a spin superconductor 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((h) over bar /2) Cooper pair with a neutral charge. We present a BCS-type theory for the spin superconductor. 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 spin superconductor/normal conductor/spin superconductor junction and predict a spin-current Josephson effect.