Symmetry Breaking and Reinforcement-Induced Non-Alter Spin Splitting in Antiferromagnet for Low-Power and High-Density Memory

Altermagnets, due to spontaneous spin splitting induced by the breaking of the PT inversion symmetry, are now widely used in the design of novel antiferromagnetic (AFM) spintronic devices. Herein, we demonstrate symmetry breaking in AFM via slip and strain engineering, achieving a non-alter spin splitting compensated magnet. As a demo concept, a four-layer sliding strategy in GdI$_2$ is put forward, enabling sliding-induced ferroelectric (FE) and magnetic switching. The FE polarization breaks PT symmetry, inducing spin-split band structures that drive AFM to ferromagnetic (FM) phase transformation or nonrelativistic spin-splitting (NRSS) AFM. The designed multiferroic tunnel junction demonstrates electric-field-controlled four-state resistance switching with low resistance area. The regulation effect of strain on the device’s transport properties has also been simulated. The compressive strain enhances the crystal symmetry in the FE-FM phase, triggering an FM-NRSS-mediated AFM transition and boosting tunneling electromagnetic resistance, providing a novel strategy and mechanism for developing low-power, high-density memory devices.