Field‐Free Programmable Spin Logics via Chirality‐Reversible Spin–Orbit Torque Switching

Spin–orbit torque (SOT)‐induced magnetization switching exhibits chirality (clockwise or counterclockwise), which offers the prospect of programmable spin‐logic devices integrating nonvolatile spintronic memory cells with logic functions. Chirality is usually fixed by an applied or effective magnetic field in reported studies. Herein, utilizing an in‐plane magnetic layer that is also switchable by SOT, the chirality of a perpendicular magnetic layer that is exchange‐coupled with the in‐plane layer can be reversed in a purely electrical way. In a single Hall bar device designed from this multilayer structure, three logic gates including AND, NAND, and NOT are reconfigured, which opens a gateway toward practical programmable spin‐logic devices. Chirality‐reversible spin–orbit torque switching in field‐free condition is realized in magnetic bilayers with crossed anisotropy. A preset current decides the direction of an in‐plane layer in Mode II. Thus, the chirality (clockwise or counterclockwise) of switching driven by another switching current can be determined in Mode I, which gives birth to a programmable logic element between AND and NAND gates.