Giant Nonvolatile Multistate Resistance with Fully Magnetically Controlled van der Waals Multiferroic Tunnel Junctions

Ferroelectric polarization switching in electrically controlled van der Waals multiferroic tunnel junctions (vdW-MFTJs) causes atomic migration, compromising device stability and fatigue resistance. Here, we propose fully magnetically controlled vdW-MFTJs based on a CrBr₃/MnPSe₃/CrBr₃ vertical heterostructure, achieving ferroelectric polarization reversal without atomic migration. First-principles calculations reveal that integrating PtTe₂/alkali-metal (Li/Na/K)-doped/intercalated CrBr₃ electrodes enables exceptional performance, with a maximum tunneling magnetoresistance (TMR) of 8.1 × 10⁵% and tunneling electroresistance (TER) of 2499%. Applying an external bias voltage enhances the TMR to 3.6 × 10⁷% and the TER to 9990%. A pronounced negative differential resistance (NDR) effect is observed with a record peak-to-valley ratio (PVR) of 9.55 × 10⁹% for vertical tunnel junctions. The spin-filtering channels are flexibly controlled by the magnetization direction of the magnetic free layer, achieving perfect spin-filtering over a broad bias range. This work paves the way for the experimental exploration of fully magnetically controlled vdW-MFTJs.