Towards Scalable Field-Free SOT-MRAM: Materials Pathways for Low-Power Switching

6th November 2025

Timing : 1 pm ET

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Spin–orbit torques (SOTs) enable fast and energy-efficient magnetic switching, yet achieving reliable field-free control of perpendicular magnetization remains a central challenge for scalable memory technologies. In this talk, I will present two complementary material strategies that realize deterministic switching without external magnetic fields. I will first present magnetic trilayers engineered to exploit all available spin-current polarizations, allowing deterministic switching without external magnetic fields while reducing the required current density. This approach is compatible with sputtered polycrystalline films, highlighting its promise for CMOS-scale manufacturing. I will then discuss epitaxial MgO/Pt/Co multilayers that leverage strong interfacial spin–orbit coupling, nanoscale anisotropy variations, and chiral interactions to achieve field-free switching with extremely large perpendicular magnetic anisotropy. Together, these approaches establish practical and fabrication-friendly pathways to field-free SOT switching. They highlight a clear route toward low-power magnetic memory and future computing technologies.

Dr. Jeongchun Ryu
Jeongchun Ryu is a Postdoctoral Associate in the Nano-Cybernetic Biotrek group at the MIT Media Lab. He received his B.S. and Ph.D. in Materials Science and Engineering from Tohoku University in Japan, where his research focused on spintronics, including spin relaxation mechanisms and spin–orbit torque phenomena in metallic systems. He then conducted postdoctoral research at the Korea Advanced Institute of Science and Technology (KAIST), advancing spin-current generation and field-free current-induced magnetization switching. Prior to joining MIT, he worked at the Samsung Advanced Institute of Technology (SAIT) on emerging non-volatile memory technologies, primarily magnetic random-access memory (MRAM). At MIT, his research focuses on materials-driven innovations in spintronic devices to achieve extreme energy efficiency and scalability, enabling next-generation computing and AI hardware.