Emergent Topological Hall Effect in Fe-doped Monolayer WSe2

TL;DR

This paper reports the observation of the topological Hall effect in Fe-doped monolayer WSe2, revealing the presence of magnetic skyrmions at room temperature in a 2D van der Waals magnetic semiconductor.

Contribution

It demonstrates the emergence of the topological Hall effect in a 2D Fe-doped WSe2 monolayer, linking skyrmions to Dzyaloshinskii-Moriya interactions at the interface.

Findings

Detection of the topological Hall effect in Fe:WSe2 monolayer.

Identification of magnetic skyrmions at room temperature.

Fe atoms substitutionally replace W atoms, creating a dilute magnetic semiconductor.

Abstract

The topological Hall effect (THE) has attracted great attention since it provides an important probe of the interaction between electron and topological spin textures. THE has been considered an experimental signature of the topological spin texture of skyrmions. While THE has been widely reported in chiral magnets, oxide heterostructures, and hybrid systems such as ferromagnet/heavy metal and ferromagnet/topological insulators, the study of monolayer structures is lacking, hindering the understanding of noncollinear spin textures at the atomically thin scale. Here, we show a discernible THE via proximity coupling of Fe-doped monolayer WSe2 (Fe:WSe2) synthesized using chemical vapor deposition on a Pt Hall bar. Multiple characterization methods were employed to demonstrate that Fe atoms substitutionally replace W atoms, making a two-dimensional (2D) van der Waals (vdW) dilute magnetic semiconductor (DMS) at room temperature. Distinct from the intrinsic anomalous Hall effect, we found the transverse Hall resistivity of Fe:WSe2 displaying two additional dip/peak features in the temperature-dependent measurements, consistent with the contribution of THE. The topological Hall effect is attributed to the magnetic skyrmions that emerge from the Dzyaloshinskii-Moriya interactions at the Fe:WSe2 and Pt interface. Our work shows that a DMS synthesized from 2D vdW transition metal dichalcogenides is promising for realizing magnetic skyrmions and spintronic applications.