Manipulation of interfacial ferrimagnetic order via proximity effect in two-dimensional heterostructures WS2/CoTb

Due to the unique properties of compensated ferrimagnets, such as long spin coherence length, fast domain wall motion, and large spin-orbit torque, to manipulate ferrimagnetic order is crucial in spintronics. Here, we investigate the proximity effect of the two-dimensional van der Waals material WS2 on the interfacial ferrimagnetic order of CoTb. By increasing the thickness of WS2 from one to three layers, a dramatic increase of ferrimagnetic compensation temperature by 75 K is observed in CoTb. Based on a two-sublattice mean-field approximation, the increased compensation temperature is ascribed to the WS2-mediated tuning of the magnetic moments of the sublattices Tb and Co, rather than from the changed exchange interactions JCo-Co and JCo-Tb. First-principles calculations reveal that the tuned magnetic moments of the sublattices Tb and Co are realized through the proximity effect, where the charge transfer occurs between the interface of CoTb and WS2. Our study proposes a viable approach to manipulate the interfacial ferrimagnetic order through the proximity effect, which has potential applications for spintronic devices.