Topological magnetotorsional effect in Weyl semimetals

TL;DR

This paper introduces a new topological thermal response in magnetic Weyl semimetals called the topological magnetotorsional effect (TME), arising from magnetization gradients and related to spacetime geometry and anomalies.

Contribution

It predicts the existence of the TME as a universal, material-independent effect linked to magnetization gradients and topological anomalies in magnetic Weyl semimetals.

Findings

TME depends on magnetization gradients and Weyl node positions.

TME is related to effective torsional spacetime geometry and Nieh-Yan anomaly.

Predicted observable in EuCd$_2$As$_2$.

Abstract

In this work we introduce a thermal magnetotorsional effect (TME) as a novel topological response in magnetic Weyl semimetals. We predict that magnetization gradients perpendicular to the Weyl node separation give rise to temperature gradients depending only on the local positions of the Weyl nodes. The TME is a consequence of magnetization-induced effective torsional spacetime geometry and the finite temperature Nieh-Yan anomaly. Similarly to anomalous Hall effect and chiral anomaly, the TME has a universal material-independent form. We predict that the TME can be observed in magnetic Weyl semimetal EuCd$_2$As$_2$.