Selective Amplification of the Topological Hall Signal in Cr$_2$Te$_3$: The Role of Molecular Exchange Coupling

TL;DR

This study demonstrates how growth engineering and molecular interfacing can control magnetic anisotropy and enhance topological Hall effects in ultra-thin Cr$_2$Te$_3$ films, advancing topological spintronic device development.

Contribution

It reveals a method to manipulate magnetic phases and amplify topological signals in Cr$_2$Te$_3$ via interface engineering and molecular coupling.

Findings

Controlled transition from in-plane to out-of-plane magnetic orientation.

Enhanced topological Hall effect through molecular interfacing.

Identification of interfacial exchange interactions as key to magnetic behavior.

Abstract

Layered magnetic transition-metal chalcogenides (TMCs) are a focal point of research, revealing a variety of intriguing magnetic and topological ground states. Within this family of TMCs, chromium telluride has garnered significant attention because of its excellent tunability in magnetic response, owing to the presence of competing magnetic exchange interactions. We here demonstrate the manipulation of magnetic anisotropy in ultra-thin Cr$_2$Te$_3$ films through growth engineering leading to a controlled transition from in-plane to out-of-plane orientation with an intermediate non-coplanar magnetic ground phase characterized by a topological Hall effect. Moreover, interfacing these films with Vanadyl phthalocyanine (VOPc) molecules prominently enhances the non-coplanar magnetic phase, attributing its presence to the competing interfacial magnetic exchange interactions over the spin-orbit-driven interfacial effects. These findings pave the way for the realization of novel topological spintronic devices through interface-modulated exchange coupling.