Challenges in magnetic modulation of 2D materials: exemplified with MoS₂

In recent years, the rapid advancement of integrated circuit technology and electronic devices has positioned two-dimensional (2D) materials as promising candidates for next-generation spintronic devices, owing to their reduced dimensions and lower energy dissipation. Despite these advantages, the majority of 2D materials are intrinsically non-magnetic. To overcome this limitation and expand the application of 2D materials in spintronics, various strategies have been developed to introduce ferromagnetic properties into non-magnetic systems. In this study, we provide a comprehensive review of recent efforts to regulate the magnetic properties of 2D non-magnetic materials through heteroatom doping. Using monolayer MoS₂doped with six different elements (V, Mn, Fe, Ni, Cu, and N) as a case study, we apply first-principles calculations to evaluate the feasibility of doping-induced magnetism by analyzing doping concentration, electronic structure stability, and the emergence of long-range magnetic order. Our findings reveal that magnetic regulation in 2D materials presents significant challenges. For theoretical researchers aiming to practically support experimental investigations into magnetic modulation in 2D materials, it is crucial to consider the following three key questions: (i). Can the desired concentration of doped atoms be successfully achieved? (ii). Do these doped atoms exhibit localized magnetic moments? (iii). Is there evidence of long-range magnetic ordering among the magnetic moments of the doped atoms?