Determining Spin Polarization of Seebeck Coefficients via Anomalous Nernst Effect

TL;DR

This paper introduces a method to determine the spin polarization of Seebeck coefficients using the anomalous Nernst effect, verified experimentally, and proposes a new mechanism for generating pure spin currents from thermal gradients.

Contribution

The study derives a linear relation between the anomalous Nernst coefficient and Hall angle, enabling spin polarization measurement, and discovers a new mechanism for pure spin current generation from temperature gradients.

Findings

Verified the linear dependence experimentally in [Co/Pt]n superlattices.

Evaluated spin polarization of Seebeck coefficients in ferromagnetic conductors.

Discovered a new mechanism for pure spin current generation from thermal energy.

Abstract

Recently, Seebeck coefficients of ferromagnetic conductors are found to be spin-dependent. However straightforward method of accurately determining its spin polarization is still to be developed. Here, we have derived a linear dependence of anomalous Nernst coefficient on anomalous Hall angle with scaling factor related to spin polarization of Seebeck coefficient, which has been experimentally verified in [Co/Pt]n superlattices. Based on the dependence, we have also evaluated spin polarization of Seebeck coefficient of some ferromagnetic conductors. Besides, we have also found a new mechanism to generate pure spin current from temperature gradient in ferromagnetic/nonmagnetic hybrid system, which could improve efficiency from thermal energy to spin current.