Interface Engineering Strategies for Magnetic and Magneto-Optical Enhancement of Two-Dimensional Fe3GeTe2.

Two-dimensional (2D) ferromagnets have great potential applications in spintronic devices. Critical temperature, exchange bias, and magnetic signal strength are key parameters for their application. To enhance the magnetism of 2D itinerant ferromagnets and amplify the emergence of new physical phenomena, different kinds of interface engineering techniques have been utilized to modulate the magnetism of 2D ferromagnets; here, Fe3GeTe2 (FGT) is selected as an example. The results show a 20 K increase in Curie temperature, an exchange bias of 0.016T, and an 11-fold enhancement of the maximum Kerr rotation angle. Specifically, in FGT/WTe2 heterostructures, interface-induced Dzyaloshinskii-Moriya interaction stabilizes skyrmions, whose density can be effectively modulated by out-of-plane current, as detected via topological reflection magnetic circular dichroism. In FGT/MnPSe3(MPSe), strong interfacial exchange coupling between the ferromagnetic and antiferromagnetic layers produces a pronounced positive exchange bias. The Au-layer microcavity synergistically enhanced dielectric modulation and plasmonic near-fields, increasing the Kerr rotation to 16.5 mradan 11-fold boostdemonstrating the potential of Au nanostructures for magneto-optical amplification. These findings clarify the physical mechanisms by which interface engineering tunes 2D ferromagnetism and provide practical strategies for designing high-performance, low-power spintronic and magneto-optical devices based on van der Waals magnetic heterostructures.