Suppression of edge magnetism in a titanium-embedded zigzag graphene nanoribbon

Electronic and magnetic properties of zigzag-edged graphene nanoribbons (ZGNR) embedded with titanium (Ti) atoms are studied by means of the first principle calculations. When Ti atoms are positioned near either edge of the ZGNR, the magnetic moment at this edge is rapidly suppressed as the Ti concentration increases, whereas the magnetism on the opposite edge is hardly affected. Rather than destroy the localized edge state of the ZGNR, the remarkable suppression of the edge magnetism by the Ti atoms originates from the antiferromagnetic coupling between the magnetic moments of a Ti atom and the ribbon edge. As a result, the Ti atoms introduce some additional subbands with spin polarization, which neutralizes the magnetic moment at the edge of the ZGNR. Such a Ti-embedded ZGNR with the unilateral magnetism can be utilized to realize the spin-polarized electronic transport.