Ferromagnetism and correlated insulating states in monolayer Mo33Te56

• Published in: arXiv.org
• Main Authors: Pan, Zemin, Xiong, Wenqi, Dai, Jiaqi, Wang, Yunhua, Tao Jian, Cui, Xingxia, Deng, Jinghao, Lin, Xiaoyu, Cheng, Zhengbo, Bai, Yusong, Zhu, Chao, Huo, Da, Li, Geng, Feng, Min, He, Jun, Ji, Wei, Yuan, Shengjun, Wu, Fengcheng, Zhang, Chendong, Hong-Jun, Gao
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 14.07.2024
• Subjects: Band theory; Correlation; Fermi level; Molybdenum compounds; Monolayers; Multilayers; Playgrounds; Scanning tunneling microscopy; Stoichiometry; Superlattices; Tellurides; Twin boundaries
• ISSN: 2331-8422

Kagome lattices have an inherent two-dimensional nature. Despite previous realizations in the monolayer limit, their abilities to drive emergent electronic states such as correlated insulators have remained unobserved. Here, we report the experimental realization of a new structural phase of monolayer Mo33Te56, characterized by its virtually global uniformity as a mirror-twin boundary loop superlattice embedded in an H-MoTe2 monolayer. Through a combination of scanning tunnelling microscopy (STM) and theoretical calculations, we unveil a kagome geometry along with multiple associated sets of kagome flat bands. Crucially, the partial filling of these kagome bands induces ferromagnetism as revealed by spin-polarized STM, and leads to a correlated insulating state exhibiting a hard gap as large as 15 meV. Our findings represent a major advance in kagome materials, offering a framework with clearer band structures and more intrinsic two-dimensional properties for exploring flat-band physics.