Xie Saien, Faeth Brendan D, Tang Yanhao, Li Lizhong, Gerber Eli, Parzyck Christopher T, Chowdhury Debanjan, Zhang Ya-Hui, Jozwiak Christopher, Bostwick Aaron, Rotenberg Eli, Kim Eun-Ah, Shan Jie, Mak Kin Fai, Shen Kyle M
Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, USA.
Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA.
Sci Adv. 2022 Mar 25;8(12):eabk1911. doi: 10.1126/sciadv.abk1911.
Moiré superlattices constructed from transition metal dichalcogenides have demonstrated a series of emergent phenomena, including moiré excitons, flat bands, and correlated insulating states. All of these phenomena depend crucially on the presence of strong moiré potentials, yet the properties of these moiré potentials, and the mechanisms by which they can be generated, remain largely open questions. Here, we use angle-resolved photoemission spectroscopy with submicron spatial resolution to investigate an aligned WS/WSe moiré superlattice and graphene/WS/WSe trilayer heterostructure. Our experiments reveal that the hybridization between moiré bands in WS/WSe exhibits an unusually large momentum dependence, with the splitting between moiré bands at the Γ point more than an order of magnitude larger than that at point. In addition, we discover that the same WS/WSe superlattice can imprint an unexpectedly large moiré potential on a third, separate layer of graphene (g/WS/WSe), suggesting new avenues for engineering two-dimensional moiré superlattices.
由过渡金属二硫属化物构建的莫尔超晶格已展现出一系列涌现现象，包括莫尔激子、平带和关联绝缘态。所有这些现象都关键取决于强莫尔势的存在，然而这些莫尔势的性质以及产生它们的机制在很大程度上仍是未解之谜。在此，我们使用具有亚微米空间分辨率的角分辨光电子能谱来研究对齐的WS/WSe莫尔超晶格和石墨烯/WS/WSe三层异质结构。我们的实验表明，WS/WSe中莫尔带之间的杂化表现出异常大的动量依赖性，Γ点处莫尔带之间的分裂比 点处大一个数量级以上。此外，我们发现同一WS/WSe超晶格能在第三层独立的石墨烯（g/WS/WSe）上施加出乎意料的大莫尔势，这为二维莫尔超晶格的工程设计开辟了新途径。
