Multiferroic Tunnel Junctions With Noncollinear Antiferromagnetic Electrodes

ABSTRACT Multiferroic tunnel junctions (MFTJs), comprising magnetic electrodes and an ultrathin ferroelectric tunnel barrier, hold great promise for the application in nonvolatile memory devices. Conventional MFTJs employ ferromagnetic (FM) electrodes, which are inherently vulnerable to stray magnetic fields and exhibit relatively slow operating speed. Here, we show, based on theoretical calculations, the feasibility of MFTJs with noncollinear antiferromagnetic (AFM) electrodes, which are expected to greatly enhance their performance. We design a Mn 3 GaN/BaTiO 3 /Mn 3 ZnN MFTJ, where noncollinear AFM antiperovskites Mn 3 GaN and Mn 3 ZnN serve as the electrodes separated by a ferroelectric BaTiO 3 tunnel barrier. Our first‐principles quantum‐transport calculations reveal sizable tunneling electroresistance (TER) and tunneling magnetoresistance (TMR) effects arising from the reversal of electric polarization of the ferroelectric barrier or the AFM Néel vectors of the electrodes, leading to four distinct resistance states. These phenomena are well explained by two key mechanisms: ferroelectricity‐induced modulation of the interfacial electronic states, which controls the momentum‐resolved transmission and underpins the TER effect; and spin‐dependent matching of bulk electrode states, which drives the TMR effect. Our work paves a new pathway to realize high‐performance MFTJs based on noncollinear antiferromagnets.