Abstract
We investigate the transverse electric field () dependence of the quantum Hall state (QHS) in dual-gated graphene bilayers in high magnetic fields. The longitudinal resistivity measured at shows an insulating behavior which is strongest in the vicinity of , as well as at large fields. At a fixed perpendicular magnetic field (), the QHS undergoes a transition as a function of the applied , marked by a minimum, temperature-independent . This observation is explained by a transition from a spin-polarized QHS at small fields to a valley- (layer-)polarized QHS at large fields. The field value at which the transition occurs follows a linear dependence on .
- Received 30 January 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.016803
© 2011 American Physical Society