Light-controlled magnetism in vanadium-doped tungsten disulfide monolayers*

Transition metal dichalcogenides (TMDs) have received growing attention for their outstanding electrical and optical properties. A promising way to induce long-range ferromagnetism (FM) in TMDs is by introducing magnetic dopants to form a dilute magnetic semiconductor. Our recent study shows room temperature (RT) FM in V-doped monolayer WSe₂ (V-WSe₂), which is an important step for TMDs based spintronics. In this work, we show light-mediated magnetism in V-WS₂ at RT. We probe this effect using the magnetic LC-resonance principle which employs a soft FM Co-based microwire coil driven near resonance with an RF signal. Combined with an excellent giant magneto-impedance effect, the coil becomes highly sensitive to changes in magnetic flux through its core. The monolayer, placed at the core of the coil, is excited with a laser as we measure the change in magnetization. Interestingly, the magnetization depends on laser power and doping concentration, demonstrating the light control of 2D magnetism. We attribute this to the generation of electron-hole pairs which mediate the magnetization of the monolayer. These findings provide a promising route to exploit light-controlled FM in 2D spintronic devices.