We calculate the spin-dependent zero-bias conductance Gσσ′ in
armchair graphene nanoribbons with hydrogen adsorbates employing a DFT-based ab
initio transport formalism including spin-orbit interaction. We find that the
spin-flip conductance Gσσˉ can reach the same order of
magnitude as the spin-conserving one, Gσσ, due to
exchange-mediated spin scattering. In contrast, the genuine spin-orbit
interaction appears to play a secondary role, only