Giant 2D Skyrmion Topological Hall Effect with Ultrawide Temperature Window and Low-Current Manipulation in 2D Room-Temperature Ferromagnetic Crystals

TL;DR

This paper reports the discovery of giant, robust 2D topological Hall effect in room-temperature ferromagnetic crystals over a wide temperature range, with low-current control, advancing potential spintronic applications.

Contribution

It demonstrates a large, stable 2D topological Hall effect across 2-300 K in Fe3GaTe2-x, with low-current manipulation, and explains the enhancement via oxidation-induced interfacial DMI.

Findings

Giant THE observed at 10 K and 300 K, larger than all known 2D skyrmion systems.

Ultrawide temperature stability of THE from 2 to 300 K.

Low critical current density (~6.2×10^5 A/cm^2) for THE control at room temperature.

Abstract

The discovery and manipulation of topological Hall effect (THE), an abnormal magnetoelectric response mostly related to the Dzyaloshinskii-Moriya interaction (DMI), are promising for next-generation spintronic devices based on topological spin textures such as magnetic skyrmions. However, most skyrmions and THE are stabilized in a narrow temperature window either below or over room temperature with high critical current manipulation. It is still elusive and challenging to achieve large THE with both wide temperature window till room temperature and low critical current manipulation. Here, by using controllable, naturally-oxidized, sub-20 and sub-10 nm 2D van der Waals room-temperature ferromagnetic Fe3GaTe2-x crystals, robust 2D THE with ultrawide temperature window ranging in three orders of magnitude from 2 to 300 K is reported, combining with giant THE of ~5.4 micro-ohm cm at 10 K and ~0.15 micro-ohm cm at 300 K which is 1-3 orders of magnitude larger than that of all known room-temperature 2D skyrmion systems. Moreover, room-temperature current-controlled THE is also realized with a low critical current density of ~6.2*10^5 A cm^-2. First-principles calculations unveil natural oxidation-induced highly-enhanced 2D interfacial DMI reasonable for robust giant THE. This work paves the way to room-temperature, electrically-controlled 2D THE-based practical spintronic devices.