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Observation of an electric-field-induced band gap in bilayer graphene by infrared spectroscopy.

TitleObservation of an electric-field-induced band gap in bilayer graphene by infrared spectroscopy.
Publication TypeJournal Article
Year of Publication2009
AuthorsMak, KFai, Lui, CHung, Shan, J, Heinz, TF
JournalPhys Rev Lett
Volume102
Issue25
Pagination256405
Date Published2009 Jun 26
ISSN0031-9007
Abstract

It has been predicted that application of a strong electric field perpendicular to the plane of bilayer graphene can induce a significant band gap. We have measured the optical conductivity of bilayer graphene with an efficient electrolyte top gate for a photon energy range of 0.2-0.7 eV. We see the emergence of new transitions as a band gap opens. A band gap approaching 200 meV is observed when an electric field approximately 1 V/nm is applied, inducing a carrier density of about 10(13) cm(-2)}. The magnitude of the band gap and the features observed in the infrared conductivity spectra are broadly compatible with calculations within a tight-binding model.

DOI10.1103/PhysRevLett.102.256405
Alternate JournalPhys. Rev. Lett.
PubMed ID19659105