Towards diluted magnetism in TaAs

TL;DR

This paper demonstrates that proton irradiation can induce room-temperature ferromagnetism in the Weyl semimetal TaAs, with magnetic moments localized around Ta atoms, opening pathways for spintronics applications.

Contribution

It introduces a novel method of inducing ferromagnetism in TaAs via proton irradiation and provides first-principles insights into the origin of magnetic moments.

Findings

Proton irradiation induces ferromagnetism in TaAs above room temperature.

Magnetic moments are localized around Ta atoms near As vacancies.

First-principles calculations link d states on Ta atoms to magnetic order.

Abstract

Magnetism in Weyl semimetals is desired to investigate the interaction between the magnetic moments and Weyl fermions, e.g. to explore anomalous quantum Hall phenomena. Here we demonstrate that proton irradiation is an effective tool to induce ferromagnetism in the Weyl semimetal TaAs. The intrinsic magnetism is observed with a transition temperature above room temperature. The magnetic moments from d states are found to be localized around Ta atoms. Further, the first-principles calculations indicate that the d states localized on the nearest-neighbor Ta atoms of As vacancy sites are responsible for the observed magnetic moments and the long-ranged magnetic order. The results show the feasibility of inducing ferromagnetism in Weyl semimetals so that they may facilitate the applications of this material in spintronics.