Spin-Charge-Lattice Coupling in 2D Magnetic Semiconductor CrSBr

The interplay of spin and charge in magnetic semiconductors lies at the heart of the field of spintronics and has attracted significant interest for new computing technologies. In this talk, I report our recent progress in studying and controlling spin-charge coupling in the layered antiferromagnetic semiconductor CrSBr. Such coupling enables the anisotropic Wannier-type excitons to serve as a powerful sensor of the interlayer magnetic order, and the generation of giant tunneling magnetoresistance (TMR) in magnetic tunnel junction (MTJ) heterostructures. Using these probes, we found that the magnetic order is extremely tunable by the application of tensile strain, with a reversible antiferromagnetic to ferromagnetic phase transition occurring at large but experimentally feasible strains. We utilize this phase transition to realize a straintronic MTJ, with zero-field TMR switching approaching 10,000% at 30 K and remaining above 100% until ~ 140 K. Moreover, the fine and continuous control of interlayer magnetic exchange coupling enables us to create metastable domains which switch stochastically with a strain-tunable sigmoidal response curve akin to the stochastic binary neuron or probabilistic bit. Our results establish CrSBr as an exciting platform for harnessing spin-charge-lattice coupling towards new, highly tunable 2D devices for spintronic applications, such as magnetic memory, random number generation, and probabilistic and neuromorphic computing.