Voltage-induced magnetization switching method utilizing dipole coupled magnetic tunnel junction

Abstract

Voltage-induced magnetization switching of multiferroic nanomagnets provides an effective method for low energy consumption writing of magnetic tunnel junction. However, this method usually requires the initial state of the tunnel junction to be read out before the logic writing. We report a numerical simulation on a novel magnetic tunnel junction of switching/insulator/auxiliary layers where the switching layer and the auxiliary layer are two non-parallel magnetostrictive layers. The magnetic tunnel junction is deposited on a piezoelectric substrate. A bottom electrode is fabricated under the substrate, and pair square surface electrodes are fabricated on both sides of the magnetic tunnel junction. The strain generated by the applied voltage and the dipole coupling effect between the two magnetostrictive layers jointly regulate the switching layer of the magnetic tunnel junction to flip by 180°. Our physical model proves that the magnetization switching in the magnetic tunnel junction can be completed by full voltage at room temperature. The logic writing of the magnetic tunnel juction is repeatable and does not need to read the initial state of the magnetostrictive layers. Besides, the energy consumption per unit area is one or two orders of magnitude lower than the state-of-the-art spin-transfer-torque magnetic tunnel junction. This method is important in the regulation of low-energy-consumption magnetic memories and spintronic devices.