  Manipulating spin in antiferromagnetic (AFM) materials has great potential in
AFM opto-spintronics. Laser pulses can induce a transient ferromagnetic (FM)
state in AFM metallic systems, but have never been proven in two-dimensional
(2D) AFM semiconductors and related van der Waals (vdW) heterostructures. Here,
using 2D vdW heterostructures of FM MnS2 and AFM MXenes as prototypes, we
investigated optically induced interlayer spin transfer dynamics based on the
real-time time-dependent density functional theory (rt-TDDFT). We observed that
laser pulses induce significant spin injection and the interfacial
atom-mediated spin transfer from MnS2 to Cr2CCl2. In particular, we first
demonstrated the transient FM state in semiconducting AFM/FM heterostructures
during photoexcited processes. Because the proximity magnetism breaks the
magnetic symmetry of Cr2CCl2 in heterostructures. Our results provide the
microscopic understanding for optically controlled interlayer spin dynamics in
2D magnetic heterostructures and open a new way to manipulate magnetic orders
in ultrafast opto-spintronics.
