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 . By measuring the temperature dependence of these resistance minima, the energy gap for the fractional state in graphene is determined to be at at 14 T.
- Received 30 September 2010
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