Hall resistance plateaus in high quality graphene samples at large currents: Toward quantization tests

Graphene Hall bars prepared from exfoliated natural graphite of large size and high quality have been measured in the quantum Hall effect regime. The monolayer Graphene sheet shows Hall quantization robust upon applying very large current. Low longitudinal resistance is found up to 10 muA with finite width h/2e
²
Hall plateau at 4.2 K and 16 T. The TiAu/Graphene contact resistance is found low, typically 20 Omega to 50 Omega. The results strongly indicate that Graphene is a promising new material for quantum metrology.