Vertical long pillar magnetic memory with two magnetic junctions

A vertical ferromagnetic (FM) pillar is proposed for use as magnetic memory with high thermal stability. The current-induced magnetization reversal of long pillars is a significant challenge in spintronic applications. We propose a novel magnetization reversal method for long pillars, based on spin injection and spin-polarized current. The magnetization direction of the pillar was controlled by the direction of the current flowing through the pillar. The magnetized direction of the pillar was determined from the two magnetoresistance values in the proposed structure. The magnetization reversal was demonstrated by a micromagnetic model simulation. A domain wall (DW) was produced during magnetization reversal. We also propose that a three-value magnetoresistive random-access memory (MRAM) can be developed by maintaining the DW in the pillar. Consequently, the proposed memory writing scheme paves the way for next-generation spintronic devices.