Protected giant magnetic anisotropy in transition-metal adatoms on defected tungsten disulfide monolayer*

Giant magnetic anisotropy, especially in systems with magnetic units protected, is very important for the development of spintronics and quantum computing devices. Through systematic first-principles calculations, we identified that Ir@D-WS2 and Os@D-WS2 may have magnetic anisotropy energies up to 40 meV even when they are covered by graphene, sufficient to frustrate the thermal fluctuation at room temperature. Moreover, the magnetic anisotropy of Os@D-WS2 can be enhanced by 300{\%} when an external electric field is applied in a range of 0.5 to -0.5 V/Å. This finding of giant magnetic anisotropy in a well protected materials opens an vista of the development of data storage and spintronic devices.