Measurement of the ν=1/3 fractional quantum hall energy gap in suspended graphene

Phys Rev Lett. 2011 Jan 28;106(4):046801. doi: 10.1103/PhysRevLett.106.046801. Epub 2011 Jan 25.

Abstract

We report on magnetotransport measurements of multiterminal suspended graphene devices. Fully developed integer quantum Hall states appear in magnetic fields as low as 2 T. At higher fields the formation of longitudinal resistance minima and transverse resistance plateaus are seen corresponding to fractional quantum Hall states, most strongly for ν=1/3. By measuring the temperature dependence of these resistance minima, the energy gap for the 1/3 fractional state in graphene is determined to be at ∼20 K at 14 T.