# A‑Site and Epitaxial Strain Effect on the Properties of AMn3Sb5 (A = K, Cs, and Rb) Kagome Lattices

## TL;DR

This paper studies the effects of A-site and strain on the properties of AMn3Sb5 Kagome lattices, revealing large anomalous Hall conductivity and stable ferromagnetism.

## Contribution

The study introduces new insights into the role of A-site and strain in stabilizing magnetic and electronic properties of Kagome lattices.

## Key findings

- The AMn3Sb5 family is dynamically stable with ferromagnetic ground-state configuration.
- Out-of-plane ferromagnetism breaks T-symmetry, enabling large anomalous Hall conductivity.
- CsMn3Sb5 shows σxy up to 442 S·cm–1 under +3% in-plane strain.

## Abstract

Kagome lattices are
an exciting family of compounds where frustrated
magnetism, superconductivity, charge density wave (CDW) orders, topological
features, large anomalous Hall conductivity, flat bands, and van Hove
singularities collide. With this in mind, we theoretically studied
the Mn-based Kagome AMn3Sb5 (A = K, Rb, and Cs) lattices and explored the A-site’s influence, as well as the epitaxial xy-strain effect on the structural, magnetic, and electronic
properties. Through theoretical analysis, coupled with first-principles
density functional theory calculations, we demonstrate that the entire
family is dynamically stable, locking the ferromagnetic order as the
ground-state configuration in the primitive cell and preventing charge-density
wave condensation, as observed in the AV3Sb5 family. In these compounds, our results suggest an
out-of-plane ferromagnetic response that, in turn, breaks the
T
-symmetry,
allowing a nonzero Berry curvature.
The latter leads to a symmetry-allowed anomalous Hall conductivity
(σ
αβ
) as large as σ
xy
= 402 S·cm–1 in
the CsMn3Sb5 and σ
xy
= 442 S·cm–1 under +3% in-plane epitaxial
strain.