Magnetoelectric synergy enabled quad-state memory in Fe3GeTe2/α-In2Se3 dual-ferroic junction

This study demonstrates a dual-ferroic tunnel junction (Fe₃GeTe₂/α-In₂Se₃/Fe₃GeTe₂) composed of a two-dimensional ferroelectric α-In₂Se₃ barrier layer and ferromagnetic Fe₃GeTe₂ (FGT) electrodes. Four distinct nonvolatile resistance states are achieved by synergistically controlling ferroelectric polarization direction (P↑/P↓) and magnetic spin alignment (parallel/antiparallel). Ferroelectric polarization reversal dynamically modulates the interfacial barrier height, establishing a low-resistance channel in the P↑ state via reduced tunneling and Schottky barriers. This mechanism enhances the current by one order of magnitude compared to the P↓ configuration, while achieving near-perfect spin-polarized transport with a spin polarization (SP) exceeding 95 %. Furthermore, the P↓ state exhibits a maximum tunneling magnetoresistance (TMR) of 144 %, whereas the parallel magnetization state demonstrates an exceptional tunneling electroresistance (TER) of 2300 %. These results reveal a synergistic amplification effect arising from ferroelectric-ferromagnetic coupling, advancing the integration of spintronics and multiferroic heterostructures for next-generation memory and logic technologies.