Ferromagnetism in armchair graphene nanoribbons

Abstract

We study the electronic correlation effects in armchair nanoribbon and\nnanotube using weak-coupling approach and non-Abelian density-matrix\nrenormalization-group method. We show that upon appropriate doping, the system\nexhibits a new type of flat-band ferromagnetism, different from the well-known\nMilke-Tasaki one. The strongly correlated ground state consists of intrinsic\nmagnetic moments of flat-band states and itinerant carriers of dispersive\nbands, and the exchange coupling between them yields a ferromagnetism. The\nresultant ferromagnetic state with metallic conductivity has a potential in\nspintronics applications at nanoscale.\n