February 15, 2012 | Matthew Yankowitz, Jiamin Xue, Daniel Cormode, Javier D. Sanchez-Yamagishi, K. Watanabe, T. Taniguchi, Pablo Jarillo-Herrero, Philippe Jacquod, Brian J. LeRoy
The paper investigates the emergence of superlattice Dirac points in graphene on hexagonal boron nitride (hBN). The authors experimentally and theoretically demonstrate that the rotation-dependent Moiré pattern formed between graphene and hBN acts as a weak periodic potential, leading to the creation of new Dirac points in the electronic structure of graphene. These new Dirac points are characterized by a reduced Fermi velocity, and the local density of states (LDOS) near these points exhibits hexagonal modulations, indicating an anisotropic Fermi velocity. The study uses scanning tunneling microscopy (STM) to observe the Moiré patterns and density of states, and theoretical calculations to model the effects of the periodic potential. The findings suggest that the superlattice Dirac points can be used to control the transport properties of electrons in graphene, potentially leading to novel graphene-based devices.The paper investigates the emergence of superlattice Dirac points in graphene on hexagonal boron nitride (hBN). The authors experimentally and theoretically demonstrate that the rotation-dependent Moiré pattern formed between graphene and hBN acts as a weak periodic potential, leading to the creation of new Dirac points in the electronic structure of graphene. These new Dirac points are characterized by a reduced Fermi velocity, and the local density of states (LDOS) near these points exhibits hexagonal modulations, indicating an anisotropic Fermi velocity. The study uses scanning tunneling microscopy (STM) to observe the Moiré patterns and density of states, and theoretical calculations to model the effects of the periodic potential. The findings suggest that the superlattice Dirac points can be used to control the transport properties of electrons in graphene, potentially leading to novel graphene-based devices.