Marchenko, D.Evtushinsky, D. V.Golias, E.Varykhalov, A.Seyller, ThRader, O.2018-12-192018-12-192018-12-192018-11-0110.1126/sciadv.aau0059https://infoscience.epfl.ch/handle/20.500.14299/153094WOS:000452212000027We propose a novel mechanism of flat band formation based on the relative biasing of only one sublattice against other sublattices in a honeycomb lattice bilayer. The mechanism allows modification of the band dispersion from parabolic to "Mexican hat"-like through the formation of a flattened band. The mechanism is well applicable for bilayer graphene-both doped and undoped. By angle-resolved photoemission from bilayer graphene on SiC, we demonstrate the possibility of realizing this extremely flattened band (< 2-meV dispersion), which extends two-dimensionally in a k-space area around the K point and results in a disk-like constant energy cut. We argue that our two-dimensional flat band model and the experimental results have the potential to contribute to achieving superconductivity of graphene- or graphite-based systems at elevated temperatures.Multidisciplinary SciencesScience & Technology - Other Topicselectronic-structuresuperconductivitydynamicstext::journal::journal article::research article