Visualizing the Localized Electrons of a Kagome Flat Band

• DOI: 10.48550/arxiv.2308.08976
• Publication Date: 2023-01-01
• Authors: Caiyun Chen; Jiangchang Zheng; Ruo-Peng Yu; Soumya Sankar; Hoi Chun Po; K. T. Law; Berthold Jäck
• Keywords: Lattice (music); Wannier function; Density of states

Destructive interference between electron wavefunctions on the two-dimensional (2D) kagome lattice induces an electronic flat band, which could host a variety of interesting many-body quantum states. Key to realize these proposals is demonstrate real space localization band electrons. In particular, extent often more complex structure and orbital composition realistic materials counteract localizing effect destructive interference, described by 2D model, hitherto unknown. We used scanning tunneling microscopy (STM) visualize non-trivial Wannier states at surface CoSn, metal. find that local density associated with bands CoSn localized center lattice, consistent theoretical expectations for their corresponding Our results show exhibit extremely small length two three angstroms concomitant strongly renormalized quasiparticle velocity, comparable moir\'e superlattices. Hence, interaction effects in be much significant than previously thought. findings provide fundamental insight into properties metals are key step future research emergent transition metal based materials.