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Updated: May 11, 2026

Fabricating van der Waals Heterostructures with Precise Rotational Alignment
Published on: July 5, 2019
Massive Dirac fermions and Hofstadter butterfly in a van der Waals heterostructure
B Hunt1, J D Sanchez-Yamagishi, A F Young
1Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Abstract:
van der Waals heterostructures constitute a new class of artificial materials formed by stacking atomically thin planar crystals. We demonstrated band structure engineering in a van der Waals heterostructure composed of a monolayer graphene flake coupled to a rotationally aligned hexagonal boron nitride substrate. The spatially varying interlayer atomic registry results in both a local breaking of the carbon sublattice symmetry and a long-range moiré superlattice potential in the graphene. In our samples, this interplay between short- and long-wavelength effects resulted in a band structure described by isolated superlattice minibands and an unexpectedly large band gap at charge neutrality. This picture is confirmed by our observation of fractional quantum Hall states at ± 5/3 filling and features associated with the Hofstadter butterfly at ultrahigh magnetic fields.
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