Full electrical control of multiple resistance states in van der Waals sliding multiferroic tunnel junctions

The recent development of two-dimensional magnetic and sliding-ferroelectric van der Waals (vdW) materials opens a new way to realize vdW sliding multiferroic tunnel junctions (MFTJs) for low-power nonvolatile memory applications. Here, we propose and investigate full electrical control of four nonvolatile resistance states in sliding MFTJs, Au/CrI₃/bilayer h-BN/CrI₃-MnBi₂Te₄/Au, via first principles. We found four stable states associated with different polarization orientations in bilayer h-BN and magnetization alignment in two CrI₃ magnetic layers, which can be controlled purely by electrical voltage and current, respectively. The MFTJ has a giant tunneling magnetoresistance (TMR) of ∼10 000% (2000% in the presence of SOC) and a sizeable tunneling electroresistance (TER) of ∼70%. The write performance is explored by spin-transfer-torque calculations which show an impressive low critical current (∼1.5 × 10¹⁰ A m^-2) to switch the magnetization of the free layer of CrI₃, while antiferromagnetic MnBi₂Te₄ pins the reference layer with a large interfacial exchange coupling.