Factors affecting the topological Hall effect in strongly correlated layered magnets: spin of the magnetic atoms, polar and azimuthal angle subtended by the spin texture

TL;DR

This paper investigates how the topological Hall effect in 2D layered magnets depends on atomic spin and spin texture angles, revealing conditions for sign changes in Hall conductivity and proposing experimental heterostructures.

Contribution

It introduces a theoretical model analyzing the influence of spin and texture angles on the topological Hall effect in strongly correlated 2D magnets, with predictions for experimental sign changes.

Findings

Chern number depends on spin and texture angles for S ≤ 3

Sign of topological Hall conductivity can reverse with spin modulation

Model applicability to various van der Waals magnets

Abstract

The Hamiltonian of a two dimensional (2D) magnetic material in the strong correlation regime with a spin texture, for which both azimuthal and polar angle changes, is solved using $su(2)$ path integral method. The dependence of the Chern number on the atomic spin ($S$), azimuthal angle ($\vec{q}_{1}$) and polar angle ($\vec{q}_{2}$) modulation vector of the spin texture on a bipartite honeycomb lattice is found. For $S \leq 3$ it was found that Chern number depends strongly on $\vec{q}_{2}$ and $S$. We discuss applicability of the model to several van der Waals magnets. Experimentally, it is expected that, with increase in spin modulation vector the sign of the topological Hall conductivity changes, $+\sigma_{xy}^{THE} \to -\sigma_{xy}^{THE}$ or vice-versa, when $S$ is constant. We also propose several heterostrucures for experimental realization of this effect.