Monolayer Kagome metals AV3Sb5

Recently, layered kagome metals AV(3)Sb(5) (A = K, Rb, and Cs) have emerged as a fertile platform for exploring frustrated geometry, correlations, and topology. Here, using first-principles and mean-field calculations, we demonstrate that AV(3)Sb(5) can crystallize in a mono-layered form, revealing a range of properties that render the system unique. Most importantly, the two-dimensional monolayer preserves intrinsically different symmetries from the three-dimensional layered bulk, enforced by stoichiometry. Consequently, the van Hove singularities, logarithmic divergences of the electronic density of states, are enriched, leading to a variety of competing instabilities such as doublets of charge density waves and s- and d-wave superconductivity. We show that the competition between orders can be fine-tuned in the monolayer via electron-filling of the van Hove singularities. Thus, our results suggest the monolayer kagome metal AV(3)Sb(5) as a promising platform for designer quantum phases. Much recent work has focused on the kagome metals AV(3)Sb(5) (A = K, Rb, and Cs), but studies of the monolayer form are only just beginning. Here, the authors theoretically study monolayer kagome metals, and predict modified van Hove singularities that lead to charge-density-wave doublets and d-wave superconductivity.

Automated summary

Recently, layered kagome metals AV(3)Sb(5) have attracted attention for their unique properties and potential for designer quantum phases. In this study, the authors explore the mono-layered form of AV(3)Sb(5) and demonstrate its different symmetries compared to the three-dimensional bulk. They predict the presence of enriched van Hove singularities, leading to various competing instabilities such as charge density waves and superconductivity. These findings highlight the monolayer kagome metal as a promising platform for further investigation and potential applications in quantum materials.