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

Abstract: 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 a fully magnetically controlled vdW-MFTJ based on a (\mathrm{CrBr_3/MnPSe_3/CrBr_3}) vertical heterostructure, which achieves ferroelectric polarization reversal without relying on atomic migration driven by inversion symmetry breaking. Using first-principles calculations, we investigate the spin-polarized quantum transport properties of the proposed structure. By integrating asymmetric PtTe$_2$/alkali-metal (Li/Na/K)-doped/intercalated CrBr$_3$ electrodes, the device demonstrates exceptional performance, with a maximum tunneling magnetoresistance (TMR) exceeding $8.1\times10^5$\% and tunneling electroresistance (TER) reaching 2499\%, while the spin-filtering channels can be flexibly controlled by the magnetization direction of the magnetic free layer, achieving perfect spin-filtering over a broad bias voltage range. Applying an external bias voltage further enhances these metrics, increasing TMR to $3.6\times 10^7$\% and TER to 9990\%. Notably, a pronounced negative differential resistance (NDR) effect is observed, yielding an unprecedented peak-to-valley ratio (PVR) of $9.55\times10^9$\%, representing the highest value reported for vertical tunnel junctions. These extraordinary characteristics highlight the potential of vdW-MFTJs for ultra-efficient electronic switching, a key feature for next-generation spintronic devices. Our findings provide a solid theoretical foundation for designing and developing high-performance magnetic storage and logic technologies.