Gate-tunable magnetism via resonant Se-vacancy levels in WSe₂

The confined defects in two-dimensional van der Waals-layered semiconductors can be easily tailored using charge doping, strain, or an electric field. Nevertheless, gate-tunable magnetic order via intrinsic defects has been rarely observed to date. Herein, we report a gate-tunable magnetic order via resonant Se vacancies in WSe₂. The Se-vacancy states were probed via photocurrent measurements with gating to convert unoccupied states to partially occupied states associated with photo-excited carrier recombination. The magneto-photoresistance hysteresis was modulated by gating, which is consistent with the density functional calculations. The two energy levels associated with Se vacancies split with increasing laser power, owing to the robust Coulomb interaction and strong spin–orbit coupling. Our results offer a new approach for controlling the magnetic properties of defects in optoelectronic and spintronic devices using van der Waals-layered semiconductors.