Domain-Selective 1D Moiré Engineering and Topological Transitions in Bilayer Graphene.

Su, Laiyuan; Gao, Yifan; Chen, Yongdao; Farooq, M Umar; Xian, Lede; Huang, Li · Nano Lett · 2025

basic_science · Level V

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Abstract

One-dimensional (1D) moiré superlattices, generated via heterostrain, provide a unique platform for engineering electronic topology and correlated states beyond the conventional two-dimensional (2D) moiré paradigm. Unlike 2D moiré patterns, 1D moiré structures selectively include specific stacking configurations, enabling domain-level control over low-energy electronic properties. Using atomistic tight-binding simulations, we demonstrate that heterostrain applied in specific directions can eliminate metallic AA-stacking regions and induce robust band gaps. As the strain decreases, the system undergoes a sequence of insulator-metal-insulator transitions, with Dirac cone formation at a critical strain of η<sub><i>c</i></sub> = 1.818%. Near this transition, we observe significant Fermi surface reconstructions, marked by van Hove singularities and Lifshitz transitions, and a sign reversal of both the Berry curvature and Berry curvature dipole. Our findings establish domain-selective 1D moiré engineering as a powerful approach for controlling low-energy physics, topology, and quantum phases in van der Waals heterostructures.