Twisted bilayer graphene (tBLG) forms a quasicrystal whose structural and electronic properties depend on the angle of rotation between its layers. Here we present a scanning tunneling microscopy study of gate-tunable tBLG devices supported by atomically-smooth and chemically inert hexagonal boron nitride (BN). The high quality of these tBLG devices allows identification of coexisting moir\'e patterns and moir\'e super-superlattices produced by graphene-graphene and graphene-BN interlayer interactions. Furthermore, we examine additional tBLG spectroscopic features in the local density of states beyond the first van Hove singularity. Our experimental data is explained by a theory of moir\'e bands that incorporates ab initio calculations and confirms the strongly non-perturbative character of tBLG interlayer coupling in the small twist-angle regime.
@article{arxiv.1510.02888,
title = {Local spectroscopy of moir\'e-induced electronic structure in gate-tunable twisted bilayer graphene},
author = {Dillon Wong and Yang Wang and Jeil Jung and Sergio Pezzini and Ashley M. DaSilva and Hsin-Zon Tsai and Han Sae Jung and Ramin Khajeh and Youngkyou Kim and Juwon Lee and Salman Kahn and Sajjad Tollabimazraehno and Haider Rasool and Kenji Watanabe and Takashi Taniguchi and Alex Zettl and Shaffique Adam and Allan H. MacDonald and Michael F. Crommie},
journal= {arXiv preprint arXiv:1510.02888},
year = {2015}
}