Large and multistate magnetoresistance in 2D van der Waals multiferroic tunnel junctions

Abstract

Multiferroic van der Waals (vdW) heterostructures hold great potential for next-generation spin-based memory and logic devices, offering versatile control over electron spins and electric polarization in atomically thin platforms. However, achieving exceptionally large tunnel magnetoresistance (TMR), stable multi-resistance states, and low resistance-area (RA) products remains a challenge. Here, using first-principles calculations, we address these issues by designing a Fe₃GaTe₂/α-In₂Se₃/Fe₃GaTe₂ multiferroic tunnel junction (MFTJ). We demonstrate large TMR values exceeding 10⁵%, nonvolatile multistate and RA product below 1 Ω µm², which matched the requirements for high-density memory cells. The remarkably low RA products from the ultrathin ferroelectric barrier’s narrow bandgap, while the exceptionally high TMR and nearly perfect spin polarization originate from enhanced momentum-selective tunneling at the Fe₃GaTe₂/α-In₂Se₃ interface. Moreover, the low energy barrier for ferroelectric switching enables efficient voltage-driven polarization control. These findings establish a clear pathway for integrating low-RA, high-TMR, and multistate MFTJs into spintronic architectures, accelerating the development of high-density, energy-efficient data storage and processing technologies.