扭曲三层WSe$_2$和MoTe$_2$中的超莫尔重构与拓扑镶嵌
Supermoiré Reconstruction and Topological Mosaics in Twisted Trilayer WSe$_2$ and MoTe$_2$
- School of Physics and Technology, Wuhan University（武汉大学物理科学与技术学院）
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所北京凝聚态物理国家研究中心）
- School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）
- Wuhan Institute of Quantum Technology（武汉量子技术研究院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过机器学习力场与从头算，揭示扭曲三层WSe$_2$和MoTe$_2$因缺乏$C_{2z}$对称性，其超莫尔晶格会重构为拓扑不等价畴的镶嵌结构，为相关物理研究提供平台。
AI中文摘要：
我们采用机器学习力场和大规模从头算，研究螺旋型与交替型扭曲三层WSe$_2$和MoTe$_2$的晶格弛豫与能带结构。两个双层莫尔晶格的干涉生成超莫尔晶格，弛豫后重构为几种占主导的畴类型，具有局域可公度的双层莫尔晶格。由于该体系缺乏$C_{2z}$对称性，原本由该对称性关联的畴在能量和拓扑上变得截然不同，这与扭曲三层石墨烯不同。能带结构计算表明，最高价带源自$K$（$K'$）谷，且带有依赖于畴的谷陈数。由此得到的超莫尔晶格承载着拓扑不等价畴的镶嵌结构，为探索关联与拓扑物理提供了平台。
英文摘要：
We investigate lattice relaxation and band structures of helical and alternating twisted trilayer WSe$_2$ and MoTe$_2$ using machine-learning force fields and large-scale ab initio calculations. Interference between the two bilayer moiré lattices generates a supermoiré lattice that, upon relaxation, reconstructs into a few dominant domain types with locally commensurate bilayer moiré lattices. Because the systems lack $C_{2z}$ symmetry, domains otherwise related by this symmetry become energetically and topologically distinct, unlike in twisted trilayer graphene. Band structure calculations show that the topmost valence bands originate from the $K$ ($K'$) valleys and carry domain-dependent valley Chern numbers. The resulting supermoiré lattice hosts a mosaic of topologically inequivalent domains, offering a platform for exploring correlated and topological physics.
