Robustness of the Quantum Hall Effect in Epitaxial Graphene
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NPL has demonstrated the accurate quantisation of the Hall resistance in epitaxial graphene on silicon carbide (SiC/G) to 3 parts in a billion.
For graphene to be practically employed as an embodiment of a quantum resistance standard it needs to satisfy further stringent requirements in particular with respect to robustness over a range of temperature, magnetic field and measurement current. We show measurements of the unusually robust Hall resistance quantization in a large SiC/G sample. We have observed the pinning of the ν = 2 state which is consistent with our picture of magnetic field dependent charge transfer between the SiC surface and graphene layer. Together with the large break-down current this makes SiC/G the ideal system for high-precision resistance metrology.
This poster was created for the EU Project ConceptGraphene that NPL is involved in. It was presented at Graphene Week 2011 in Austria and at the topical meeting on graphene organised by the IOP in May 2011.