2009/08/05 by A. B. Kuzmenko, I. Crassee, D. van der Marel +2 · 2 citations
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.80.165406
published as Phys. Rev. B 80, 165406 (2009) · 13 pages, 10 figures
arxiv created 2009/08/05 · arxiv updated 2015/05/13
We present a compelling evidence for the opening of a bandgap in exfoliated bottom-gated bilayer graphene by fitting the gate-voltage modulated infrared reflectivity spectra in a large range of doping levels with a tight-binding model and the Kubo formula. A close quantitative agreement between the experimental and calculated spectra is achieved, allowing us to determine self-consistently the full set of Slonczewski-Weiss-McClure tight-binding parameters together with the gate-voltage dependent bandgap. The doping dependence of the bandgap shows a good agreement with the existing calculations that take the effects of self-screening into account. We also identify certain mismatches between the tight-binding model and the data, which can be related to electron-electron and electron-phonon interactions.