Large and multistate magnetoresistance in 2D van der Waals multiferroic tunnel junctions
Multiferroic van der Waals heterostructures offer a route to atomically thin spintronic memory and logic, yet the simultaneous attainment of large tunnel magnetoresistance (TMR), stable multi-resistance states, and low resistance-area (RA) product remains unresolved. This work employs first-principles calculations to design a Fe3GaTe2/α-In2Se3/Fe3GaTe2 multiferroic tunnel junction (MFTJ). The device exhibits TMR exceeding 10^5%, nonvolatile multistate operation, and RA product below 1 Ω μm2, satisfying high-density memory cell requirements. The exceptionally low RA product arises from the narrow bandgap of the ultrathin ferroelectric barrier, while the high TMR and near-perfect spin polarization stem from enhanced momentum-selective tunneling at the Fe3GaTe2/α-In2Se3 interface. A low energy barrier for ferroelectric switching enables efficient voltage-driven polarization control. These findings establish a pathway for integrating low-RA, high-TMR, multistate MFTJs into spintronic architectures, accelerating high-density, energy-efficient data storage and processing technologies.