Revolutionizing Power Consumption Reduction in Ultra-High-Speed Magnetic Memory

KAIST Develops New Spin Material Technology

Schematic diagram of spin material technology development for ultra-high-speed magnetic memory.

[Asia Economy Reporter Kim Bong-su] KAIST announced on the 27th that a joint research team led by Professor Byung-guk Park of the Department of Materials Science and Engineering and Professor Kyung-jin Lee of the Department of Physics has developed spin material technology that drastically reduces the energy consumption power of spin-orbit torque magnetic memory (hereinafter SOT-MRAM), which is being developed as a high-speed non-volatile memory.

SOT-MRAM is attracting attention as the next-generation magnetic memory due to its characteristics of high-speed operation and high stability. However, this technology requires the application of an external magnetic field for magnetization switching, and the switching current is larger than that of conventional spin-transfer torque magnetic memory (STT-MRAM), resulting in high power consumption during magnetic memory operation. Therefore, for the practical use of SOT-MRAM, the development of material technology with high switching efficiency that operates without an external magnetic field is required.

The research team revealed through theory and experiments that a spin current with three directions of spin polarization is generated in a new spin material structure, namely a single-crystal ferromagnetic/transition metal bilayer structure, and by combining these, they announced results that effectively reduce the magnetization reversal switching current, which determines the operating energy of magnetic memory.

This new material increases spin-orbit torque efficiency and enables operation without an external magnetic field, which is expected to accelerate the practical application of SOT-MRAM. Due to its high-speed operation and non-volatile characteristics, SOT-MRAM can reduce standby power consumption of existing semiconductor devices, making it highly promising for use as memory in mobile, wearable, and IoT (Internet of Things) devices that require low power.

In this study, the research team theoretically and experimentally proved that spin currents with spin polarization in three directions?x, y, and z?can be generated in a bilayer structure of single-crystal ferromagnetic material with high crystallinity and current. Furthermore, by controlling the magnetization direction and current direction, they secured conditions where spin torque efficiency is maximized, successfully developing technology that drastically reduces switching current. This technology is expected to be utilized as a core material technology to reduce the operating power consumption of SOT-MRAM.

Dr. Jung-chun Ryu, the first author, stated, "This study experimentally demonstrated that spin currents in multiple directions can be simultaneously generated and controlled within magnetic memory, which can be utilized in the development of spintronic devices operating at low power."

The results of this study were published online on the 7th in the international academic journal Nature Electronics.

This content was produced with the assistance of AI translation services.