Magnetic texture-induced thermal Hall effects

TL;DR

This paper explores how magnetic textures induced by spin-orbit interactions in 2D insulators generate thermal Hall effects, highlighting contributions from geometric textures and spin-orbit terms across various magnetic ground states.

Contribution

It reveals the dual origin of fictitious magnetic fields and demonstrates thermal Hall effects in domain walls and skyrmion lattices in 2D ferromagnets with spin-orbit coupling.

Findings

Thermal Hall effects occur in certain domain walls.

Skyrmion lattices exhibit thermal Hall responses.

Both geometric and spin-orbit contributions are significant.

Abstract

Magnetic excitations in ferromagnetic systems with a noncollinear ground state magnetization experience a fictitious magnetic field due to the equilibrium magnetic texture. Here, we investigate how such fictitious fields lead to thermal Hall effects in two-dimensional insulating magnets in which the magnetic texture is caused by spin-orbit interaction. Besides the well-known geometric texture contribution to the fictitious magnetic field in such systems, there exists also an equally important contribution due to the original spin-orbit term in the free energy. We consider the different possible ground states in the phase diagram of a two-dimensional ferromagnet with spin-orbit interaction: the spiral state and the skyrmion lattice, and find that thermal Hall effects can occur in certain domain walls as well as the skyrmion lattice.