Multiflavor Dirac fermions in Kekulé-distorted graphene bilayers

Abstract

Graphene's electronic structure can be fundamentally altered when a substrate- or adatom-induced Kekul\'e superlattice couples the valley and isospin degrees of freedom. Here, we show that the band structure of Kekul\'e-textured graphene can be reengineered through layer stacking. We predict a family of Kekul\'e graphene bilayers that exhibit up to six-valley band structures, and room-temperature Dirac quasiparticles whose masses can be tuned electrostatically, constituting a versatile platform for valleytronics. Slower Fermi velocities than in pristine graphene make this system a good candidate to study many-body correlations of multiflavor models.