Emergent giant topological Hall effect in twisted Fe3GeTe2 metallic system

TL;DR

This study reports a giant topological Hall effect in twisted Fe3GeTe2, occurring only within a specific twist angle range, due to skyrmion lattices induced by local inversion symmetry breaking.

Contribution

It demonstrates the emergence of a giant topological Hall effect in a globally inversion-symmetric twisted magnetic system within a narrow twist angle window.

Findings

Giant topological Hall effect observed at specific twist angles (0.45° to 0.75°).

Skyrmion lattice formation driven by local inversion symmetry breaking.

Potential for engineering topological magnetic textures in twisted van der Waals magnets.

Abstract

The topological Hall effect, driven by the exchange interaction between conduction electrons and topological magnetic textures such as skyrmions, is a powerful probe for investigating the topological properties of magnetic materials. Typically, this phenomenon arises in systems with broken global inversion symmetry, where Dzyaloshinskii-Moriya interactions stabilize such textures. Here, we report the discovery of an emergent giant topological Hall effect in the twisted Fe3GeTe2 metallic system, which notably preserves the general global inversion symmetry. This effect manifests exclusively within a narrow window of "magic" twist angles ranging from 0.45{\deg} to 0.75{\deg}, while it is absent identically outside of that range, highlighting its unique and emergent nature. Micromagnetic simulations reveal that this topological Hall effect originates from a skyrmion lattice induced by alternating in-plane and layer-contrasting Dzyaloshinskii-Moriya interactions that result from local inversion symmetry breaking. Our findings underscore twisted Fe3GeTe2 as a versatile platform for engineering and controlling topological magnetic textures in metallic twisted van der Waals magnets, thereby opening up new avenues for next-generation spintronic devices.