Quasi-free-standing graphene

• Applicant: Professor Dr. Carsten Busse
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 242334915

The two-dimensional material graphene has a whole set of fascinating properties like high mobility of relativistic charge carriers, ballistic transport, transparency, high mechanical strength, and ideal surface to mass ratio. Confining the geometry to quasi-1D structures [graphene nanoribbons (GNR)] and quasi-0D structures [graphene quantum dots (GQD)] allows to tune the properties of graphene and to induce new effects: The confinement of Dirac electrons leads to a discretization of states and in consequence also to the band gap that is necessary for the use of graphene in tran-sistors. At the edges of graphene nanostructures a peculiar edge state is predicted. It is situated at the Fermi level and hence governs the transport properties in the case of highly ordered edges. Most probably this edge state is spin-polarized which could help to transform graphene into a half-metal and hence into a spin-filter material. Experimental evidence for this state is scarce and many questions are open. A general problem is that for real samples the detection and analysis of the effects mentioned above is often hampered by the coupling of graphene to its environment, which is on the one hand due to the two-dimensional phase boundary due to the interface between ex-tended graphene and its substrate and on the other hand due to the one-dimensional phase boundary defined by the edge of graphene nanostructures. In this proposal we will develop hybrid materials of graphene and hexagonal boron nitride that have properties very close to free-standing graphene and allow for a thorough investigation of the special electronic properties.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1459: Graphen