Van der Waals Spin-Orbit Torque Antiferromagnetic Memory

Modern magnetic random-access memory (MRAM) technology requires all-electric control of magnetization with high speed and low energy consumption. Here, we design field-free spin-orbit torque (SOT) MRAM using a two-dimensional Van der Waals heterostructure with antiferromagnetic bilayer LaBr2 and inversion asymmetric monolayer Td-WTe2. Our calculations, combining density functional theory with nonequilibrium Green function methods and micromagnetic simulations, show that the proposed SOT device has a low critical current density and can achieve field-free and very fast switching of magnetization, which makes excellent writing operation. It also has sensitive reading ability due to a high tunnel magnetoresistance ratio up to 1200%. Our work offers new opportunities for 2D spin-orbitronics.