  The insulating magnetic phase in graphene zigzag ribbons, predicted both by
density functional and mean field Hubbard model calculations, is described
without additional approximations with a BCS wave function of two phase-locked
condensates of spin-polarized electron-hole pairs. The associated order
parameter is the spin dipole operator that features both magnetic and electric
order and accounts for the spin-resolved ferroelectricity of the system. Each
condensate is associated to a spin-dependent dipole and their relative phase
locking sets the total electric dipole and total magnetization equal to zero.
