Isolated hydrogen atoms chemisorbed on graphene have been predicted to induce magnetic moments. Direct observation of these magnetic moments and their interactions as well as their manipulation still remains a major experimental challenge. Here I will show that the adsorption of a single hydrogen atom on graphene induces a magnetic moment characterized by a 20 meV spin-split state at the Fermi energy. Our scanning tunneling microscopy (STM) experiments, complemented by first-principles calculations, show that such a spin-polarized state is essentially localized on the carbon sublattice complementary to the one where the H atom is chemisorbed. This atomically modulated spin-texture, which extends several nanometers away from the H atom, drives the direct coupling between the magnetic moments at unusually long distances. Using the STM tip to manipulate H atoms with atomic precision, we are able to select the adsorption sites and tailor the magnetism of large graphene regions [1]. Furthermore, under the appropriate conditions a spontaneous adsorption of H on only one sublattice can be achieved [2] with its concomitant  long-range ferromagnetic order [3]. A proposal to use hydrogenated graphene as spin-polarized current injector, thus avoiding metal-contacts, will be presented.

Isolated hydrogen atoms chemisorbed on graphene have been predicted to induce magnetic moments. Direct observation of these magnetic moments and their interactions as well as their manipulation still remains a major experimental challenge. Here I will show that the adsorption of a single hydrogen atom on graphene induces a magnetic moment characterized by a 20 meV spin-split state at the Fermi energy. Our scanning tunneling microscopy (STM) experiments, complemented by first-principles calculations, show that such a spin-polarized state is essentially localized on the carbon sublattice complementary to the one where the H atom is chemisorbed. This atomically modulated spin-texture, which extends several nanometers away from the H atom, drives the direct coupling between the magnetic moments at unusually long distances. Using the STM tip to manipulate H atoms with atomic precision, we are able to select the adsorption sites and tailor the magnetism of large graphene regions [1]. Furthermore, under the appropriate conditions a spontaneous adsorption of H on only one sublattice can be achieved [2] with its concomitant  long-range ferromagnetic order [3]. A proposal to use hydrogenated graphene as spin-polarized current injector, thus avoiding metal-contacts, will be presented.