A Reconfigurable Al2S3/LuCl2 Multiferroic Tunnel Junction with Giant Tunneling Electroresistance and Magnetoresistance for High-Performance Memory

Abstract

Van der Waals multiferroic tunnel junctions (vdW-MFTJs) have emerged as promising platforms for exploring novel physical phenomena and developing next-generation memory devices by integrating tunneling electroresistance (TER) and tunneling magnetoresistance (TMR) to achieve multiple non-volatile resistance states. Nevertheless, realizing simultaneously large TER and TMR ratios remains challenging. In this work, we propose a multiferroic heterostructure based on Al₂S₃ and LuCl₂. Switching the polarization direction of the ferroelectric (FE) Al₂S₃ layer induces a semiconductor-to-metal transition, originating from interfacial band offset and interfacial charge reconstruction due to work function differences. When LuCl₂ serves as the central channel, the MFTJ exhibits an exceptional TER ratio of 7.08×10¹¹ %, a TMR ratio of 5.8×10⁸ %, a perfect spin-injection effect (SIE) of 100 % at equilibrium, and AND spin-logic functionality. Conversely, when Al₂S₃ acts as the tunnel barrier, the junction achieves a TER ratio of 2.9×10⁷ % under a bias voltage of 0.05 V, which can be further enhanced to 6.472×10⁹ % in a six channels (N=6) configuration. Furthermore, the device can be reversibly switched between “off” and “on” states by modulating the out-of-plane ferroelectric polarization of Al₂S₃. These results demonstrate the significant potential of the reconfigurable Al₂S₃/LuCl₂ vdW heterostructure for high-performance memory devices.