Giant Topological Hall Effect in Magnetic Weyl Metal Mn$_{2}$Pd$_{0.5}$Ir$_{0.5}$Sn

TL;DR

This paper reports a giant topological Hall effect in a magnetic Weyl metal, Mn$_{2}$Pd$_{0.5}$Ir$_{0.5}$Sn, due to its non-trivial band topology and unique magnetic order, with potential for spintronic applications.

Contribution

The study demonstrates the realization of topologically protected magnetic order and a large topological Hall effect in a novel Weyl Heusler alloy, confirmed by first principles calculations and micromagnetic simulations.

Findings

42 pairs of Weyl nodes near the Fermi level

Giant topological Hall effect observed at low fields

Potential antiskyrmion lattice formation

Abstract

The synergy between real and reciprocal space topology is anticipated to yield a diverse array of topological properties in quantum materials. We address this pursuit by achieving topologically safeguarded magnetic order in novel Weyl metallic Heusler alloy, Mn$_{2}$Pd$_{0.5}$Ir$_{0.5}$Sn. The system possesses non-centrosymmetric D$_{2d}$ crystal symmetry with notable spin-orbit coupling effects. Our first principles calculations confirm the topological non-trivial nature of band structure, including 42 pairs of Weyl nodes at/near the Fermi level, offering deeper insights into the observed anomalous Hall effect mediated by intrinsic Berry curvature. A unique canted magnetic ordering facilitates such rich topological features, manifesting through an exceptionally large topological Hall effect at low fields. The latter is sustained even at room temperature and compared with other known topological magnetic materials. Detailed micromagnetic simulations demonstrate the possible existence of an antiskyrmion lattice. Our results underscore the $D_{2d}$ Heusler magnets as a possible platform to explore the intricate interplay of non-trivial topology across real and reciprocal spaces to leverage a plethora of emergent properties for spintronic applications.