Kagome surface states and weak electronic correlation in vanadium-kagome metals

TL;DR

This study investigates the electronic structures of vanadium-kagome metals RV6Sn6 using ARPES and calculations, revealing weak correlations and tunable kagome surface states influenced by interlayer coupling.

Contribution

It provides a systematic analysis of surface states in RV6Sn6, demonstrating weak electronic correlations and the R-element-dependent tunability of kagome surface states.

Findings

Weak electronic correlation evidenced by matching calculations and ARPES data.

Observation of R-element-dependent 'W'-like kagome surface states.

Potential for tuning electronic states via interlayer coupling.

Abstract

RV6Sn6 (R = Y and lanthanides) with two-dimensional vanadium-kagome surface states is an ideal platform to investigate kagome physics and manipulate the kagome features to realize novel phenomena. Utilizing the micron-scale spatially resolved angle-resolved photoemission spectroscopy and first-principles calculations, we report a systematical study of the electronic structures of RV6Sn6 (R = Gd, Tb, and Lu) on the two cleaved surfaces, i.e., the V- and RSn1-terminated (001) surfaces. The calculated bands without any renormalization match well with the main ARPES dispersive features, indicating the weak electronic correlation in this system. We observe 'W'-like kagome surface states around the Brillouin zone corners showing R-element-dependent intensities, which is probably due to various coupling strengths between V and RSn1 layers. Our finding suggests an avenue for tuning electronic states by interlayer coupling based on two-dimensional kagome lattices.