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

TL;DR

This paper introduces a fully magnetically controlled van der Waals multiferroic tunnel junction with exceptional resistance switching performance, surpassing previous devices in TMR, TER, and NDR effects, promising advances in spintronic applications.

Contribution

It proposes a novel vdW-MFTJ design that achieves ferroelectric polarization reversal without atomic migration, with record-high TMR, TER, and PVR, based on first-principles calculations.

Findings

Maximum TMR exceeds 8.1×10^5%

Tunneling electroresistance reaches 2499%

Peak-to-valley ratio of NDR effect is 9.55×10^9%

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.