Two-Dimensional Fully Compensated Ferrimagnetism.

Antiferromagnetic spintronics has long been a subject of intense research interest, and the recent introduction of altermagnetism has further ignited enthusiasm in the field. However, fully compensated ferrimagnetism, which exhibits band spin splitting but zero net magnetization, has yet to receive enough attention. Since the experimental preparation of two-dimensional (2D) magnetic van der Waals (vdW) materials in 2017, 2D magnetic materials, thanks to their super tunability, have quickly become an important playground for spintronics. Here, we extend the concept of fully compensated ferrimagnetism (fFIM) to two dimensions and propose 2D filling-enforced fFIM, demonstrate its stability and ease of manipulation, and present three feasible realization schemes with respective exemplary candidate materials. A simple model for 2D fully compensated ferrimagnets (fFIMs) is developed. Further investigation of 2D fFIMs' physical properties reveals that they not only exhibit significant magneto-optical response but also show fully spin-polarized currents and the anomalous Hall effect in the half-metallic states, displaying characteristics previously almost exclusive to ferromagnetic materials, greatly broadening the research and application prospects of spintronic materials.