Ultrafast Light-Induced Ferromagnetic State in Transition Metal Dichalcogenides Monolayers

Ultrafast optical control of magnetism had great potential to revolutionizemagnetic storage technology and spintronics, but for now, its potential remains mostlyuntapped in two-dimensional (2D) magnets. Here, using the state-of-the-art real-time time-dependent density functional theory (rt-TDDFT), we demonstrate that an ultrafast laser pulsecan induce a ferromagnetic state in nonmagnetic MoSe2monolayers interfaced with van derWaals (vdW) ferromagnetic MnSe2. Our results show that the transient ferromagnetism inMoSe2derives from photoinduced direct ultrafast interlayer spin transfer from Mn to Mo via avdW-coupled interface, albeit with a delay of approximately a few femtoseconds. This delaywas strongly dependent on laser duration and interlayer coupling, which could be used to tunethe amplitude and rate spin transfer. Furthermore, we have also shown that ferromagneticstates can be photoinduced in other transition metal dichalcogenides (TMDs), such as PtS2and TaSe2monolayers. Overall, ourfindings provide crucial physical insights for exploringlight-induced interlayer spin and charge dynamics in 2D magnetic systems

Automated summary

This study demonstrates the ultrafast optical control of magnetism in two-dimensional magnets through real-time time-dependent density functional theory. The results provide insights into light-induced interlayer spin and charge dynamics, which could impact magnetic storage technology and spintronics.