Direct electrical probing of anomalous Nernst conductivity

TL;DR

This paper introduces a straightforward electrical method to directly measure anomalous Nernst conductivity in magnetic materials, demonstrated on a Weyl semimetal, facilitating research in topological materials and thermoelectrics.

Contribution

The paper presents a novel, simple experimental technique for directly probing anomalous Nernst conductivity using a closed circuit setup, validated on a magnetic Weyl semimetal.

Findings

Accurately measured $oldsymbol{ ext{α}}^{A}_{xy}$ over a wide temperature range.

Validated the method's effectiveness on Co$_{2}$MnGa thin films.

Potential to advance topological materials and thermoelectric research.

Abstract

Despite the usefulness of the anomalous Nernst conductivity ($\alpha^{A}_{xy}$) for studying electronic band structures and exploring magnetic materials with large transverse thermopower, there has not been a straightforward way to obtain $\alpha^{A}_{xy}$ in the experiment. Here, we propose a simple and versatile method enabling direct electrical probing of $\alpha^{A}_{xy}$, which is realized by creating a closed circuit consisting of a target magnetic material and a non-magnetic conductor. This method was experimentally demonstrated on a thin film of magnetic Weyl semimetal Co$_{2}$MnGa, where the closed circuit was formed simply by connecting both ends of the Co$_{2}$MnGa film with a Au wire. A good approximation of $\alpha^{A}_{xy}$ was obtained in a wide temperature range, validating the proposed method and exhibiting its potential for aiding the further development of topological materials science and transverse thermoelectrics.