Experimental observation of low-dimensional magnetism in graphene nanostructures

Abstract The high carrier mobility, large spin coherent length, and potentially high Curie temperature make graphene and its nanostructures promising candidates for applications in spintronics. Magnetism could be induced in graphene nanostructures without magnetic element doping. This idea is appealing not only because it is a novel physics phenomenon, but also because it makes the realization of magnetism in graphene nanostructures in an easy way possible. This chapter will introduce the physical mechanism of the onset of magnetism in graphene nanostructures and experimental observation of these magnetic states, especially by scanning tunneling microscopy technique. The magnetism in graphene nanostructures is categorized into three cases: (1) zero-dimensional graphene fragments, (2) one-dimensional edges in graphene nanoribbons, and (3) disordered defects in graphene nanostructures. In all cases, the theoretical calculations promise the magnetic properties in graphene nanostructures. However, the realization of the magnetism in graphene nanostructures in practical devices and the observation of these magnetic states remain open issues.