Twist-Induced Modification in the Electronic Structure of Bilayer WSe<sub>2</sub>
Ding Pei, Zishu Zhou, Zhihai He, Liheng An, Han Gao, Hanbo Xiao, Cheng Chen, Shanmei He, Alexei Barinov, Jianpeng Liu, Hongming Weng, Ning Wang, Zhongkai Liu, Yulin Chen
Abstract
The recent discovery of strongly correlated phases in twisted transition-metal dichalcogenides (TMDs) highlights the significant impact of twist-induced modifications on electronic structures. In this study, we employed angle-resolved photoemission spectroscopy with submicrometer spatial resolution (μ-ARPES) to investigate these modifications by comparing valence band structures of twisted (5.3°) and nontwisted (AB-stacked) bilayer regions within the same WSe 2 device. Relative to the nontwisted region, the twisted area exhibits pronounced moiré bands and ∼90 meV renormalization at the Γ-valley, substantial momentum separation between different layers, and an absence of flat bands at the K-valley. We further simulated the effects of lattice relaxation, which can flatten the Γ-valley edge but not the K-valley edge. Our results provide a direct visualization of twist-induced modifications in the electronic structures of twisted TMDs and elucidate their valley-dependent responses to lattice relaxation.