Half integer quantum Hall effect in high mobility single layer epitaxial graphene

The quantum Hall effect, with a Berry's phase of π is demonstrated here on a single graphene layer grown on the C-face of 4H silicon carbide. The mobility is ∼20 000 cm²/Vṡs at 4 K and 15 000 cm²/Vṡs at 300 K despite contamination and substrate steps. This is comparable to the best exfoliated graphene flakes on SiO2 and an order of magnitude larger than Si-face epitaxial graphene monolayers. These and other properties indicate that C-face epitaxial graphene is a viable platform for graphene-based electronics.