Topological Quantum Materials with Kagome Lattice

TL;DR

This paper reviews recent progress on topological quantum properties in kagome lattice materials, highlighting magnetic and nonmagnetic types, their unique electronic behaviors, and emergent quantum phenomena.

Contribution

It provides a comprehensive overview of the electronic, magnetic, and topological properties of kagome lattice materials, emphasizing new quantum effects and their tunability.

Findings

Magnetic kagome materials exhibit large anomalous Hall effects due to topological bands.

Nonmagnetic kagome materials show coexistence of superconductivity, charge density waves, and band topology.

Tunability via pressure or doping reveals interplay between electronic correlations and topology.

Abstract

In this account, we will give an overview of our research progress on novel quantum properties in topological quantum materials with kagome lattice. Here, there are mainly two categories of kagome materials: magnetic kagome materials and nonmagnetic ones. On one hand, magnetic kagome materials mainly focus on the 3d transition-metal-based kagome systems, including Fe$_3$Sn$_2$, Co$_3$Sn$_2$S$_2$, YMn6Sn6, FeSn, and CoSn. The interplay between magnetism and topological bands manifests vital influence on the electronic response. For example, the existence of massive Dirac or Weyl fermions near the Fermi level signicantly enhances the magnitude of Berry curvature in momentum space, leading to a large intrinsic anomalous Hall effect. In addition, the peculiar frustrated structure of kagome materials enables them to host a topologically protected skyrmion lattice or noncoplaner spin texture, yielding a topological Hall effect that arises from the realspace Berry phase. On the other hand, nonmagnetic kagome materials in the absence of longrange magnetic order include CsV3Sb5 with the coexistence of superconductivity, charge density wave state, and band topology and van der Waals semiconductor Pd$_3$P$_2$S$_8$. For these two kagome materials, the tunability of electric response in terms of high pressure or carrier doping helps to reveal the interplay between electronic correlation effects and band topology and discover the novel emergent quantum phenomena in kagome materials.