  Optical methods for magnetism manipulation have been considered as a
promising strategy for ultralow-power and ultrahigh-speed spin switches, which
becomes a hot spot in the field of spintronics. However, a widely applicable
and efficient method to combine optical operation with magnetic modulation is
still highly desired. Here, the strongly correlated electron material VO2 is
introduced to realize phase-transition based optical control of the magnetism
in NiFe. The NiFe/VO2 bilayer heterostructure features appreciable modulations
in electrical conductivity (55%), coercivity (60%), and magnetic anisotropy
(33.5%). Further analyses indicate that interfacial strain coupling plays a
crucial role in this modulation. Utilizing this optically controlled magnetism
modulation feature, programmable Boolean logic gates (AND, OR, NAND, NOR, XOR,
NXOR and NOT) for high-speed and low-power data processing are demonstrated
based on this engineered heterostructure. As a demonstration of
phase-transition spintronics, this work may pave the way for next-generation
electronics in the post-Moore era.
