Electrically Controlled Multi-State Memory Magnetic Tunnel Junctions Based on Multiferroic Tunneling Barriers
Magnetic tunnel junctions (MTJs) with multiferroic tunneling barriers offer a pathway to fully electrically controlled multi-state memory, addressing the high energy costs and scalability limits of magnetically controlled counterparts. In this work, we propose a theoretical design achieving four or ten distinct resistance states via electrical control, with a giant tunneling magnetoresistance (TMR) ratio of 1.1×10^4% (11000%). This value surpasses all previously reported MTJs, including experimental systems such as CoFeB/MgO/CoFeB (TMR 65%, 4 states) and theoretical systems like Ga2O3/MgO/Ga2O3 (TMR 1120%, 2 states). The multiferroic barrier enables simultaneous control of ferroelectric and magnetic order parameters, allowing reversible switching between multiple resistance levels without external magnetic fields. Our first-principles calculations reveal that the high TMR arises from spin-dependent tunneling through the barrier, modulated by the ferroelectric polarization direction and magnetization configuration. The device operates with low write energy and exhibits non-volatile retention, making it suitable for high-density storage and in-memory computing. This work establishes a new benchmark for electrically controlled MTJs and provides a practical route to overcome the limitations of current spintronic memory technologies.