Anomalous Nernst effect in a microfabricated Weyl magnet Mn₃Sn

Weyl magnets have attracted much attention in condensed matter physics due to both the fundamental interest and the potential application of a new thermoelectric power generation and heat current sensor. An anomalous Nernst effect is a thermoelectric phenomenon typically observed in ferromagnets under the application of a temperature gradient. The anomalous Nernst effect provides a simple and powerful tool to track the position and motion of a domain wall propagating. Recent theoretical and experimental studies have shown that magnetic domains exist in noncollinear antiferromagnetic Weyl magnets.
In this study, we have investigated the anomalous Nernst effect in a microfabricated antiferromagnetic Weyl magnet Mn₃Sn to detect magnetic domains and observed step structures in hysteresis of the anomalous Nernst effect. We discuss the origin of the step structures in the hysteresis and compare the anomalous Nernst effect in the device to that in a bulk single crystal.