Observation of {\Gamma}-valley moiré bands and emergent hexagonal lattice in twisted transition metal dichalcogenides

• Published in: arXiv.org 2022-05
• Main Authors: Ding Pei, Wang, Binbin, Zhou, Zishu, He, Zhihai, An, Liheng, He, Shanmei, Chen, Cheng, Li, Yiwei, Wei, Liyang, Liang, Aiji, Avila, Jose, Dudin, Pavel, Kandyba, Viktor, Giampietri, Alessio, Cattelan, Mattia, Barinov, Alexei, Liu, Zhongkai, Liu, Jianpeng, Weng, Hongming, Wang, Ning, Xue, Jiamin, Chen, Yulin
• Format: Article
• Language: English
• Subjects: Chalcogenides; Electronic structure; Heterostructures; Hexagonal lattice; Kagome lattice; Photoelectric emission; Scanning tunneling microscopy; Spatial resolution; Superlattices; Transition metal compounds; Valleys
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2205.13788

Twisted van der Waals heterostructures have recently been proposed as a condensed-matter platform for realizing controllable quantum models due to the low-energy moiré bands with specific charge distributions in moiré superlattices. Here, combining angle-resolved photoemission spectroscopy with sub-micron spatial resolution ({\mu}-ARPES) and scanning tunneling microscopy (STM), we performed a systematic investigation on the electronic structure of 5.1{\deg} twisted bilayer WSe2 that hosts correlated insulating and zero-resistance states. Interestingly, contrary to one's expectation, moiré bands were observed only at {\Gamma}-valley but not K-valley in {\mu}-ARPES measurements; and correspondingly, our STM measurements clearly identified the real-space honeycomb- and Kagome-shaped charge distributions at the moiré length scale associated with the {\Gamma}-valley moiré bands. These results not only reveal the unsual valley dependent moiré-modified electronic structure in twisted transition metal dichalcogenides, but also highlight the {\Gamma}-valley moiré bands as a promising platform for exploring strongly correlated physics in emergent honeycomb and Kagome lattices at different energy scales.