Anisotropic band flattening in graphene with one-dimensional superlattices
- 15 February 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Nanotechnology
- Vol. 16 (5), 525-530
- https://doi.org/10.1038/s41565-021-00849-9
Abstract
Patterning graphene with a spatially periodic potential provides a powerful means to modify its electronic properties1,2,3. In particular, in twisted bilayers, coupling to the resulting moiré superlattice yields an isolated flat band that hosts correlated many-body phases4,5. However, both the symmetry and strength of the effective moiré potential are constrained by the constituent crystals, limiting its tunability. Here, we have exploited the technique of dielectric patterning6 to subject graphene to a one-dimensional electrostatic superlattice (SL)1. We observed the emergence of multiple Dirac cones and found evidence that with increasing SL potential the main and satellite Dirac cones are sequentially flattened in the direction parallel to the SL basis vector, behaviour resulting from the interaction between the one-dimensional SL electric potential and the massless Dirac fermions hosted by graphene. Our results demonstrate the ability to induce tunable anisotropy in high-mobility two-dimensional materials, a long-desired property for novel electronic and optical applications7,8. Moreover, these findings offer a new approach to engineering flat energy bands where electron interactions can lead to emergent properties9.Keywords
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Funding Information
- United States Department of Defense | United States Navy | Office of Naval Research (N00014-17-1-2832, N00014-17-1-2832, N00014-17-1-2832, N00014-17-1-2832)
- Science and Technology Commission of Shanghai Municipality (19ZR1436400)
- NYU-ECNU Institute of Physics at NYU Shanghai
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