Magnetism and anomalous transport in the Weyl semimetal PrAlGe: Possible route to axial gauge fields

TL;DR

This paper investigates the magnetic Weyl semimetal PrAlGe, demonstrating how its magnetic properties influence anomalous transport phenomena and proposing nanoscale magnetic textures as a route to axial gauge fields for Weyl fermions.

Contribution

It experimentally links ferromagnetism in PrAlGe to anomalous Hall and Nernst effects and suggests magnetic textures as a means to realize tunable axial gauge fields.

Findings

PrAlGe exhibits large anomalous Hall and Nernst effects consistent with first-principles calculations.

Magnetic fields can connect to Weyl nodes via Pr magnetization in PrAlGe.

Nanoscale magnetic textures may serve as local platforms for axial gauge fields.

Abstract

In magnetic Weyl semimetals, where magnetism breaks time-reversal symmetry, large magnetically sensitive anomalous transport responses are anticipated that could be useful for topological spintronics. The identification of new magnetic Weyl semimetals is therefore in high demand, particularly since in these systems Weyl node configurations may be easily modified using magnetic fields. Here we explore experimentally the magnetic semimetal PrAlGe, and unveil a direct correspondence between easy-axis Pr ferromagnetism and anomalous Hall and Nernst effects. With sizes of both the anomalous Hall conductivity and Nernst effect in good quantitative agreement with first principles calculations, we identify PrAlGe as a system where magnetic fields can connect directly to Weyl nodes via the Pr magnetization. Furthermore, we find the predominantly easy-axis ferromagnetic ground state co-exists with a low density of nanoscale textured magnetic domain walls. We describe how such nanoscale magnetic textures could serve as a local platform for tunable axial gauge fields of Weyl fermions.