Spin Seebeck in the weak exchange coupled van der Waals antiferromagnet

TL;DR

This paper demonstrates the spin Seebeck effect in the weak exchange coupled van der Waals antiferromagnet CrPS4, revealing how the effect varies across the spin-flip transition and providing new insights into magnetic excitations in such materials.

Contribution

It reports the first observation of the spin Seebeck effect in a van der Waals antiferromagnet, specifically CrPS4, and explores its behavior across the spin-flip transition.

Findings

SSE increases with magnetic field before the spin-flip transition.

A peak in SSE occurs at the spin-flip field.

SSE behavior is linked to magnon mode edges across the transition.

Abstract

Spin Seebeck effect (SSE) refers to the creation of spin currents due to a temperature gradient in the magnetic materials or across magnet-normal metal interfaces, which can be electrically detected through the inverse spin Hall effect (ISHE) when in contact with heavy metals. It offers fundamental insights into the magnetic properties of materials, including the magnetic phase transition, static magnetic order, and magnon excitations. However, the SSE in van der Waals antiferromagnet is still elusive, especially across the spin-flip transition. Here, we demonstrate the SSE in the weak exchange coupled van der Waals antiferromagnet CrPS$_4$. The SSE increases as the magnetic field increases before the spin-flip transition due to the enhancement of the thermal spin current as a function of the applied field. A peak of SSE is observed at the spin-flip field, which is related to the magnon mode edges across the spin-flip field. Our results extend SSE research to van der Waals antiferromagnets and demonstrate an enhancement of SSE at the spin-flip transition.