Quantum Oscillations Evidence for Topological Bands in Kagome Metal ScV6Sn6

TL;DR

This study provides experimental evidence of topological electronic bands in the kagome metal ScV6Sn6 through quantum oscillation measurements, confirming the presence of Dirac and topological features predicted by theory.

Contribution

It offers the first experimental confirmation of topological bands in ScV6Sn6 via quantum oscillations, supporting theoretical models of its electronic structure.

Findings

Quantum oscillations match band structure models.

Berry phase around π indicates topological bands.

Evidence supports the existence of Dirac dispersions.

Abstract

Metals with kagome lattice provide bulk materials to host both the flat-band and Dirac electronic dispersions. A new family of kagome metals is recently discovered in AV6Sn6. The Dirac electronic structures of this material need more experimental evidence to confirm. In the manuscript, we investigate this problem by resolving the quantum oscillations in both electrical transport and magnetization in ScV6Sn6. The revealed orbits are consistent with the electronic band structure models. Furthermore, the Berry phase of a dominating orbit is revealed to be around $\pi$, providing direct evidence for the topological band structure, which is consistent with calculations. Our results demonstrate a rich physics and shed light on the correlated topological ground state of this kagome metal.