Energy Efficient Computing With High-Density, Field-Free STT-Assisted SOT-MRAM (SAS-MRAM)

Energy efficient computing hardware has played an instrumental role in enabling novel abundant data applications and transformative new user experiences. As we look forward, many emerging nonvolatile memory technologies have been proposed to further improve the energy efficiency of tomorrow’s computing systems. Spin–orbit torque magnetoresistive random access memory (SOT-MRAM) and its variants are one class of emerging nonvolatile memory technology, which promises static random access memory (SRAM)-like performance at a higher bit-cell density. In this article, we discuss high-density, field-free spin-transfer torque (STT)-assisted SOT-MRAM (SAS-MRAM) as an emerging nonvolatile memory technology, which could drastically improve the energy efficiency of future computing systems. Such benefits are enabled by sharing the SOT line between one or many magnetic tunnel junctions (MTJs), thereby amortizing the areal and energy costs of the SOT drive transistor across multiple bits.