Stable Antisymmetric Magnetoresistance in Fe₃GaTe₂/InSe/Fe₃GaTe₂ van der Waals Heterostructures With Multi-State...

Ferromagnetic van der Waals (vdW) heterostructures are pivotal for next-generation spintronics, especially in realizing novel functionalities like antisymmetric magnetoresistance (ASMR). While ASMR holds immense potential for multi-state memory and logic operations, achieving stable performance across a broad range of conditions and realizing diverse multi-state functionalities remain key challenges. Here, we report the demonstration of multi-state ASMR signals in a Fe₃GaTe₂/InSe/Fe₃GaTe₂ vdW heterostructure, effectively operating up to 320 K. Intriguingly, the conventional three-state ASMR undergoes a unique temperature-induced shape reversal, which is precisely correlated with the temperature-dependent crossover of the coercive fields of the two Fe₃GaTe₂ layers. Through adapted measurement configurations, an unconventional four-state ASMR, featuring distinct high, intermediate-1, intermediate-2, and low resistance states, has been obtained, holding significant promise for enhancing multi-state memory density. Crucially, the device exhibits superior signal stability across wide variations in bias current (0.01-100 µA) and magnetic field angle (0^°-360^°). Programmable prototype devices demonstrating highly distinguishable states are also presented. The junction resistance of our devices is only a few kiloohms owing to the perfect Fermi level alignment between Fe₃GaTe₂ and InSe, making them highly compatible with complementary metal-oxide-semiconductor circuits. This work lays a solid foundation for future stable multi-state memory applications.