Magnetic Memory Technologies

This lecture covers the evolution from traditional electronic memory to spintronics, focusing on Magnetic Random Access Memory (MRAM) and its advantages over Dynamic Random-Access Memory (DRAM). It explains the principles of spin transport, the role of non-magnetic spacers, magnetoresistance, and the construction of MRAM using magnetic tunnel junctions. The instructor discusses the reading-writing process in Hard Disk Drives (HDD) and the importance of spacer materials and crystal structures in spin junction performance. Additionally, the lecture delves into MRAM writing mechanisms using magnetic fields and spin-polarized currents, as well as real-space imaging of antiferromagnetism on the atomic scale. It concludes with insights on artificially constructed quantum magnets and bistability in atomic-scale antiferromagnets.