Fan, KaiquanKaiquanFanVan Beek, SimonSimonVan BeekTalmelli, GiacomoGiacomoTalmelliKateel, VaishnaviVaishnaviKateelGiuliano, DomenicoDomenicoGiulianoVermeulen, Bob BertBob BertVermeulenCai, KaimingKaimingCaiSorée, BartBartSoréeDe Boeck, JoJoDe BoeckCarpenter, RobertRobertCarpenterRao, SiddharthSiddharthRaoCouet, SebastienSebastienCouetNguyen, Van DaiVan DaiNguyenKar, Gouri SankarGouri SankarKar2026-07-092026-07-0920260003-69511077-3118https://imec-publications.be/handle/20.500.12860/59801We present micromagnetic simulations and experiments on voltage-assisted field switching in perpendicular magnetic tunnel junctions (MTJs) with a synthetic antiferromagnetic (SAF) free layer, where the magnetic state of one sublayer is detected via tunneling magnetoresistance (TMR). Simulations reveal that local modulation of perpendicular magnetic anisotropy in one SAF sublayer leads to distinct switching characteristics. The switching field varies linearly with the anisotropy field, indicating voltage-controlled magnetic anisotropy (VCMA)-dominated dynamics similar to single free-layer devices. We then experimentally study the magnetic switching field of MTJ devices with SAF free layers under applied gate voltage. By varying the MgO tunnel barrier thickness to systematically modulate the resistance-area (RA) product, we enable quantitative separation of spin-transfer torque (STT), VCMA, and Joule heating contributions. Our findings indicate that VCMA dominates in devices with a high-RA product, while low-RA devices exhibit nonlinear switching behavior due to enhanced contributions from STT and Joule heating. Furthermore, the effective fields derived from STT, VCMA, and Joule heating contributions under various gate voltages show minimal dependence on device critical dimensions, indicating favorable scaling behavior. This work presents a unified framework analyzing the roles of STT, VCMA, and Joule heating in SAF-based voltage-gated spin–orbit torque (SOT) magnetic random-access memory (MRAM), offering key insights for the optimization of performance, energy efficiency, and scalability in SOT-MRAM technologies.engJournal article10.1063/5.0289550WOS:0017024439000011077-3118