Magnetic orderings from spin-orbit coupled electrons on kagome lattice

TL;DR

This paper explores how spin-orbit coupling influences magnetic orderings in kagome lattice electrons, revealing diverse magnetic phases and their dependence on electron filling and SOC type, with implications for kagome materials.

Contribution

It demonstrates that simple kagome lattice models can host various magnetic orders influenced by SOC, providing insights into magnetic phases in related materials.

Findings

SOC stabilizes noncollinear magnetic orders

Electron filling determines magnetic phase

Kagome lattice hosts ferromagnetic and antiferromagnetic states

Abstract

We investigate magnetic orderings on kagome lattice numerically from the tight-binding Hamiltonian of electrons, governed by the filling factor and spin-orbit coupling (SOC) of electrons. We find that even a simple kagome lattice model can host both ferromagnetic and noncollinear antiferromagnetic orderings depending on the electron filling, reflecting gap structures in the Dirac and flat bands characteristic to the kagome lattice. Kane--Mele- or Rashba-type SOC tends to stabilize noncollinear orderings, such as magnetic spirals and 120-degree antiferromagnetic orderings, due to the effective Dzyaloshinskii--Moriya interaction from SOC. The obtained phase structure helps qualitative understanding of magnetic orderings in various kagome-layered materials with Weyl or Dirac electrons.