Thermally driven pure spin and valley current via anomalous Nernst effect in monolayer group-VI dichalcogenides

TL;DR

This paper investigates how thermal gradients can generate pure spin and valley currents in monolayer group-VI dichalcogenides via the anomalous Nernst effect, offering new possibilities for spin caloritronics applications.

Contribution

It introduces the analysis of spin and valley dependent anomalous Nernst effects in monolayer MoS2 and related materials, highlighting the generation of pure spin and valley currents.

Findings

Pure spin and valley currents can be generated perpendicular to thermal gradients.

A spin current purity factor quantifies the effect.

Dip-peak features in Nernst coefficient occur when time reversal symmetry is broken.

Abstract

Spin and valley dependent anomalous Nernst effect are analyzed for monolayer MoS2 and other group-VI dichalcogenides. We find that pure spin and valley currents can be generated perpendicular to the applied thermal gradient in the plane of these two-dimensional materials. This effect provides a versatile platform for applications of spin caloritronics. A spin current purity factor is introduced to quantify this effect. When time reversal symmetry is violated, e.g. two-dimensional materials on an insulating magnetic substrate, a dip-peak feature appears for the total Nernst coefficient. For the dip state it is found that carriers with only one spin and from one valley are driven by the temperature gradient.