Nonvolatile multistate magnetoresistance in all-van der Waals antiferromagnet-based spin valves

Antiferromagnets are gaining increasing significance in spintronics due to their advantageous properties, such as picosecond spin dynamics and negligible stray fields. However, their practical application is hindered by the challenges associated with electrical detection methods. Here, we report the observation of multistate magnetoresistance (MR) in all-van der Waals antiferromagnet-based heterojunctions. By employing an A-type antiferromagnet (Fe0.8Co0.2)3GaTe2 (FCGaT) as the magnetic electrode, we fabricate spin valve devices based on the FCGaT/WSe2/FCGaT heterojunction. The nonvolatile MR arises from changes in the conductance of the heterojunction due to the magnetic phase transitions of the FCGaT layers. Our findings expand the potential applications of antiferromagnets in spintronics and pave the way for the development of next-generation memory devices with high density and ultrafast operation.