Tuning the Intrinsic Spin Hall Effect by Charge Density Wave Order in Topological Kagome Metals

TL;DR

This study investigates how charge density wave order influences the intrinsic spin Hall effect in topological kagome metals, revealing large spin Hall conductivities and potential for spintronics applications.

Contribution

It provides ab-initio calculations showing the impact of CDW order on SHE in kagome metals, highlighting their tunability and topological band structure effects.

Findings

Large spin Hall conductivities comparable to Weyl semimetals

SHE strongly renormalized by charge density wave order

SHE dominated by Dirac nodal line topology

Abstract

Kagome metals are topological materials with a rich phase diagram featuring various charge density wave orders and even unconventional superconductivity. However, little is still known about possible spin-polarized responses in these non-magnetic compounds. Here, we perform ab-initio calculations of the intrinsic spin Hall effect (SHE) in the kagome metals AV$_3$Sb$_5$ (A=Cs, Rb, K), CsTi$_3$Bi$_5$ and ScV$_6$Sn$_6$. We report large spin Hall conductivities, comparable with the Weyl semimetal TaAs. Additionally, in CsV$_3$Sb$_5$ the SHE is strongly renormalized by the CDW order. We can understand these results based on the topological properties of band structures, demonstrating that the SHE is dominated by the position and shape of the Dirac nodal lines in the kagome sublattice. Our results suggest kagome materials as a promising, tunable platform for future spintronics applications.