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 similar to 10 000% (2000% in the presence of SOC) and a sizeable tunneling electroresistance (TER) of similar to 70%. The write performance is explored by spin-transfer-torque calculations which show an impressive low critical current (similar to 1.5 x 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. We introduce a concept of full electrical control of four states in a vdW sliding multiferroic tunnel junction with a giant TMR and a sizeable TER. The STT writing current is one order of magnitude smaller than traditional bulk counterparts.