Dirac Fermion Cloning, Moir$\bf{\'e}$ Flat Bands and Magic Lattice Constants in Epitaxial Monolayer Graphene
Abstract
Tuning interactions between Dirac states in graphene has attracted enormous interest because it can modify the electronic spectrum of the two-dimensional material, enhance electron correlations, and give rise to novel condensed-matter phases such as superconductors, Mott insulators, Wigner crystals and quantum anomalous Hall insulators. Previous works predominantly focus on the flat band dispersion of coupled Dirac states from different graphene layers. In this work, we propose a new route to realizing flat band physics in monolayer graphene under a periodic modulation from substrates. We take gaphene/SiC heterostructure as a role model and demonstrate experimentally the substrate modulation leads to Dirac fermion cloning and consequently, the proximity of the two Dirac cones of monolayer graphene in momentum space. Our theoretical modeling captures the cloning mechanism of Dirac states and indicates that flat bands can emerge at certain magic lattice constants of substrate when the period of modulation becomes nearly commensurate with the supercell of graphene. The results show that the epitaxial monolayer graphene is a promising platform for exploring exotic many-body quantum phases arising from interactions between Dirac electrons.
Keywords
Cite
@article{arxiv.2103.10401,
title = {Dirac Fermion Cloning, Moir$\bf{\'e}$ Flat Bands and Magic Lattice Constants in Epitaxial Monolayer Graphene},
author = {Qiangsheng Lu and Ching-Kai Chiu and Congcong Le and Jacob Cook and Xiaoqian Zhang and Xiaoqing He and Mohammad Zarenia and Mitchel Vaninger and Paul F. Miceli and Chang Liu and Tai-Chang Chiang and Giovanni Vignale and Guang Bian},
journal= {arXiv preprint arXiv:2103.10401},
year = {2022}
}