Role of External Stimuli in Engineering Magnetic Phases and Real-Time Spin Dynamics of Co/Mn Oxides

Magnetism in atomically thin two-dimensional (2D) materials can be easily manipulated by alloying, functionalization, external ultrafast laser pulse, strain, electric field, etc. In this work, we have performed a series of spin-resolved density functional theory calculations on 2D magnetic hexagonal transition-metal oxide alloys, CoMnO₄. We have explored different alloy patterns and found the most stable magnetic phases in each pattern, resulting in a stable ferromagnetic (FM) ground state depending upon the pattern. We have used Janus functionalization in these materials to tune the magnetic nature of the system from FM to antiferromagnetic (AFM) states. To further control the spin dynamics, we have applied an ultrafast laser pulse to the Janus systems to explore an AFM-to-FM transition process. Finally, applying strain and electric field to the Janus alloys allows us to tune the structure-property relationship in the 2D layers to obtain desirable spin arrangements.