Giant Topological Hall Effect in van der Waals Heterostructures of CrTe2/Bi2Te3

TL;DR

This paper reports a giant topological Hall effect in van der Waals heterostructures of CrTe2 and Bi2Te3, demonstrating a significant interfacial effect due to optimized 2D ferromagnetism, strong spin-orbit coupling, and sharp interfaces, with potential for quantum and storage applications.

Contribution

It presents the first observation of a giant topological Hall effect in CrTe2/Bi2Te3 heterostructures, highlighting the role of interface engineering in enhancing topological phenomena.

Findings

Giant topological Hall effect of 1.39 μΩ·cm observed

Optimized combination of 2D ferromagnetism and strong SOC

CrTe2/Bi2Te3 heterostructures as a platform for large THE

Abstract

Discoveries of interfacial topological Hall effect (THE) provide an ideal platform for exploring physics arising from the interplay between topology and magnetism. The interfacial topological Hall effect is closely related to the Dzyaloshinskii-Moriya interaction (DMI) at interface and topological spin textures. However, it is difficult to achieve a sizable THE in heterostructures due to the stringent constraints on the constituents of THE heterostructures such as strong spin-orbit coupling (SOC). Here we report the observation of a giant THE signal of 1.39 $\mu\Omega\cdot$cm in the van der Waals heterostructures of CrTe2/Bi2Te3 fabricated by molecular beam epitaxy, a prototype of two-dimensional (2D) ferromagnet (FM)/topological insulator (TI). This large magnitude of THE is attributed to an optimized combination of 2D ferromagnetism in CrTe2, strong SOC in Bi2Te3, and an atomically sharp interface. Our work reveals CrTe2/Bi2Te3 as a convenient platform for achieving large interfacial THE in hybrid systems, which could be utilized to develop quantum science and high-density information storage.