发表机构
Harvard University; University of California at Berkeley; National Institute for Materials Science（哈佛大学; 加州大学伯克利分校; 国立材料研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种基于MEMS的可重构石墨烯莫尔平台，通过原位旋转实现扭转角连续控制，利用拉曼光谱验证莫尔势并解析声子杂化，为关联与拓扑现象研究提供可重复参考。
AI 中文摘要
扭转范德华（vdW）系统为探索涌现关联现象（包括超导、磁性和拓扑相）提供了强大平台。扭转角为修改底层哈密顿量提供了连续调谐参数，然而精确且可重复的控制仍具挑战性。现有方法受限于一次性器件架构、受限的角度精度或垂直探测几何。在此，我们引入一种可重构的石墨烯基莫尔平台，其中两个独立制备的层通过微机电系统（MEMS）机械组装并在原位旋转。拉曼光谱证实了扭转诱导莫尔势的形成和稳健性，并实现了扭转角的连续、确定性控制。莫尔势折叠电子能带结构并激活纵向光学（LO）声子模式，使我们能够绘制其色散并直接可视化莫尔动量。通过双共振2D模式的演化，解析了角度依赖的电子能带杂化。在接近0°时，Γ点G模式声子的涌现不对称性揭示了由莫尔超晶格势和层间弛豫驱动的声子能带折叠和杂化。我们的平台为扭转双层石墨烯提供了可重复的拉曼参考，同时消除了器件间的变异性。更广泛地，它确立了扭转角作为可确定性控制参数，用于系统研究莫尔量子材料中的关联和拓扑现象。
英文摘要
Twisted van der Waals (vdW) systems provide a powerful platform for exploring emergent correlated phenomena, including superconductivity, magnetism, and topological phases. The twist angle offers a continuous tuning parameter for modifying the underlying Hamiltonian, however, precise and reproducible control remains challenging. Existing approaches are limited by single-use device architectures, restricted angular precision, or vertical probing geometries. Here we introduce a reconfigurable graphene-based moiré platform in which two independently fabricated layers are mechanically assembled and rotated in situ using a micro-electromechanical system (MEMS). Raman spectroscopy confirms the formation and robustness of the twist-induced moiré potential and enables continuous, deterministic control of the twist angle. The moiré potential folds the electronic band structure and activates the longitudinal optical (LO) phonon mode, allowing us to map its dispersion and directly visualize the moiré momentum. Angle-dependent electronic band hybridization is resolved through the evolution of the double-resonant 2D mode. Near \(0^\circ\), an emergent asymmetry of the \(Γ\)-point G-mode phonon reveals phonon band folding and hybridization driven by the moiré superlattice potential and interlayer relaxation. Our platform provides a reproducible Raman reference for twisted bilayer graphene while eliminating device-to-device variability. More broadly, it establishes the twist angle as a deterministically controllable parameter for systematic studies of correlated and topological phenomena in moiré quantum materials.
