Using scanning-tunneling-microscopy and theoretical modeling on heterostructures of twisted bilayer graphene and hexagonal Boron-Nitride, we show that the emergent super-moire structures display a rich landscape of moire-crystals and quasicrystals. We reveal a phase-diagram comprised of commensurate moire-crystals embedded in swaths of moire quasicrystals. The 1:1 commensurate crystal, expected to be a Chern insulator, should only exist at one point on the phase-diagram, implying that it ought to be practically undetectable. Surprisingly we find that the commensurate crystals exist over a much wider than predicted range, providing evidence of an unexpected self-alignment mechanism that is explained using an elastic-network model. The remainder of the phase-diagram, where we observe tunable quasicrystals, affords a new platform for exploring the unique electronic-properties of these rarely found in nature structures.
@article{arxiv.2311.07819,
title = {Imaging Self-aligned Moir\'e Crystals and Quasicrystals in Magic-angle Bilayer Graphene on hBN Heterostructures},
author = {Xinyuan Lai and Daniele Guerci and Guohong Li and Kenji Watanabe and Takashi Taniguchi and Justin Wilson and Jedediah H. Pixley and Eva Y. Andrei},
journal= {arXiv preprint arXiv:2311.07819},
year = {2023}
}