Thermally generated magnon transport in quasi-two-dimensional antiferromagnetic materials

Magnon spintronics studies the transport of spin currents through an insulating and magnetically ordered material using magnons [1]. Electrically and thermally induced magnons can be transported in insulating ferromagnetic [2] and antiferromagnetic materials [3]. In particular, antiferromagnetic materials have interesting properties for future spintronic applications: they possess no net magnetic moment and are therefore robust against magnetic perturbations and have ultrafast dynamics. We investigate the transport of magnons in the insulating antiferromagnetic van der Waals materials: MnPS3, NiPS3, FePS3, and CoPS3. The spin structure depends on the transition metal: MnPS3 and FePS3 are uniaxial antiferromagnets whereas NiPS3 and CoPS3 are easy plane antiferromagnets. The spin currents are injected electrically, via the spin Hall effect, and thermally, via joule heating, and detected via the inverse spin Hall effect using the nonlocal geometry as described in Ref.[2]. We observe thermally injected magnon transport in MnPS3, NiPS3, and FePS3 as a function of an in-plane orientation of an external magnetic field [4]. Next to that, the Spin Hall magnetoresistance measurements in Pt on top of FePS3 show a strong correlation to the magnetic susceptibility of FePS3 [5].