Multiferroic Tunnel Junctions: The Future of Spintronic Devices?

As the scaling limits of conventional CMOS technologies become increasingly evident due to issues like power dissipation and quantum effects, spintronic devices are emerging as viable alternatives for nextgeneration electronics. Among these, multiferroic tunnel junctions (MFTJs) have gained significant attention for their potential to realize high-density, energy-efficient, and non-volatile memory and logic systems. MFTJs integrate a ferroelectric barrier between two ferromagnetic electrodes, combining the tunneling magnetoresistance (TMR) of magnetic tunnel junctions (MTJs) with the tunnelingelectroresistance (TER) of ferroelectric tunnel junctions (FTJs). This dual functionality enables four non-volatile resistance states, controllable by electric and magnetic fields. Beyond this binary extension, strong magnetoelectric coupling at the ferromagnet/ferroelectric interface—driven by mechanisms such as spin-dependent screening and interfacial charge redistribution—offers voltage-based control of magnetic and spintronic properties. This review surveys the fundamental operating principles, experimental breakthroughs, and material systems enabling TMR, TER, and tunnelingelectromagnetoresistance (TEMR) in MFTJs. Emphasis is placed on interface engineering strategies and the performance metrics of various device architectures, including room-temperature-operable systems. The continuing development of MFTJs holds promise for multifunctional device applications in memory, logic, and neuromorphic computing.