Advanced Spin Orbit Torque Magnetic Random Access Memory with Field-Free Switching Schemes (Invited)

Magnetic random access memory (MRAM) is considered a promising candidate for future both standalone and embedded memory technology. The emerging spin orbit torque (SOT) mechanism is expected to alternate the traditional spin transfer torque (STT) writing scheme. However, the need of undesirable magnetic field limits the application of SOT mechanism. In this invited paper, we outline our latest achievements on the field-free SOT-MRAM. First, we proposed a toggle spin torque MRAM (TST-MRAM) by combining STT and SOT. Second, we experimentally demonstrated a voltage-gated SOT mechanism assisted by voltage-controlled magnetic anisotropy (VCMA) and in-plane exchange bias (EB). Finally, we presented a current-path-dependent SOT mechanism aided by uniaxial shape anisotropy.