Abstract
We demonstrate that the electronic gap of a graphene bilayer can be controlled externally by applying a gate bias. From the magnetotransport data (Shubnikov–de Haas measurements of the cyclotron mass), and using a tight-binding model, we extract the value of the gap as a function of the electronic density. We show that the gap can be changed from zero to midinfrared energies by using fields of , below the electric breakdown of . The opening of a gap is clearly seen in the quantum Hall regime.
- Received 15 November 2006
DOI:https://doi.org/10.1103/PhysRevLett.99.216802
©2007 American Physical Society