Phase Control of Graphene Nanoribbon by Carrier Doping: Appearance of Noncollinear Magnetism
journal contributionposted on 14.01.2009, 00:00 by Keisuke Sawada, Fumiyuki Ishii, Mineo Saito, Susumu Okada, Takazumi Kawai
The zigzag graphene nanoribbon (ZGNR) has an antiferromagnetic property, that is, the relative spin angle θ between the two edges is 180°. By using noncollinear first-principles calculations, we find that the magnetic phase of the ZGNR can be controlled by injecting either electrons or holes: as the carrier density increases, θ continuously decreases from 180 to 0°, which indicates that the net magnetization is possible. Either FET doping or chemical doping is found to be possible.