Biased bilayer graphene: semiconductor with a gap tunable by the electric field effect.
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 less, approximately < 1 V/nm, below the electric breakdown of SiO2. The opening of a gap is clearly seen in the quantum Hall regime.
Castro
Eduardo V
EV
CFP and Departamento de Física, Faculdade de Ciências Universidade do Porto, P-4169-007 Porto, Portugal.
Novoselov
K S
KS
Morozov
S V
SV
Peres
N M R
NM
dos Santos
J M B Lopes
JM
Nilsson
Johan
J
Guinea
F
F
Geim
A K
AK
Neto
A H Castro
AH