Tuning the nontrivial topological properties of the Weyl semimetal CeAlSi

TL;DR

This study investigates how external pressure influences the topological and magnetic properties of the ferromagnetic Weyl semimetal CeAlSi, revealing pressure-dependent changes in Hall effects and magnetic transition temperature.

Contribution

It demonstrates that pressure can tune the topological features and Hall effects in CeAlSi without significantly altering its magnetic structure or electronic bands.

Findings

Pressure suppresses anomalous and loop Hall effects.

Curie temperature increases with pressure.

Magnetic structure remains largely unchanged under pressure.

Abstract

In the ferromagnetic Weyl semimetal CeAlSi both space-inversion and time-reversal symmetries are broken. We use external pressure as an effective tuning parameter and relate three observations to the presence of a nontrivial topology in its ferromagnetic regime: an exceptional temperature response of the quantum oscillations amplitude, the presence of an anomalous Hall effect (AHE), and the existence of an unusual loop Hall effect (LHE). We find a suppression of the AHE and the LHE with increasing pressure, while the Curie temperature is enhanced. The magnetic structure and the electronic bands exhibit only a negligible pressure effect suggesting the importance of the domain wall landscape for the topological behavior in CeAlSi.