Ferromagnetic state above room temperature in a proximitized topological Dirac semimetal

TL;DR

This study demonstrates a ferromagnetic state above room temperature in a Dirac semimetal heterostructure, revealing large anomalous Hall effects linked to Berry curvature, and offers a new platform for topological spintronics research.

Contribution

It introduces a ferromagnetic Dirac semimetal heterostructure with above-room-temperature ferromagnetism and significant anomalous Hall effects, advancing topological spintronics applications.

Findings

Ferromagnetic order observed above room temperature.

Large anomalous Hall conductivity proportional to magnetization.

Theoretical analysis links Hall effects to Berry curvature from Weyl nodes.

Abstract

We report an above-room-temperature ferromagnetic state realized in a proximitized Dirac semimetal, which is fabricated by growing typical Dirac semimetal Cd$_3$As$_2$ films on a ferromagnetic garnet with strong perpendicular magnetization. Observed anomalous Hall conductivity with substantially large Hall angles is found to be almost proportional to magnetization and opposite in sign to it. Theoretical calculations based on first-principles electronic structure also demonstrate that the Fermi-level dependent anomalous Hall conductivity reflects the Berry curvature originating in the split Weyl nodes. The present Dirac-semimetal/ferromagnetic-insulator heterostructure will provide a novel platform for exploring Weyl-node transport phenomena and spintronic functions lately proposed for topological semimetals.