stt mram

STT-MRAM (spin-transfer-torque MRAM) stores a bit as the relative magnetic orientation of two ferromagnetic layers separated by a thin insulating tunnel barrier, switching that orientation using a spin-polarized current passed directly through the magnetic tunnel junction rather than using an external magnetic field the way earlier field-switched MRAM designs required. This current-driven switching approach, rather than external-field switching, is specifically what made STT-MRAM practical to scale to the bit densities and low switching energies needed for competitive commercial non-volatile memory applications.