Calendar of Events
Chiral spintronics: non collinear spin textures with application to Racetrack Memory
Speaker: Stuart S.P. Parkin, Max Planck Institute for Microstructure Physics, Halle (Saale), Germany
Abstract: Today we live in a digital world in which vast quantities of digital data are generated and stored in the cloud. These data have allowed for transformations of nearly all aspects of our lives in just a decade or so. Much of this digital data is stored in magnetic hard disk drives, a fifty-year-old technology that relies on the mechanical motion of a recording read-write head across a whirling disk covered with a thin magnetic film. This talk discusses the physics of a novel disruptive technology, Racetrack Memory, derived from the emerging field of chiral spintronics that could replace magnetic disk drives. Racetrack Memory is a dense, high performance, low energy consuming, non-volatile solid-state memory-storage technology, that stores digital data in the form of the presence or absence of chiral domain walls. These magnetic domain walls are moved by spin currents, to and thro, along magnetic racetracks to reading and writing elements, thereby allowing for digital storage densities 100 times greater than is possible in today’s charge-based memory technologies. Racetrack Memory is made possible by remarkable recent discoveries in spin-based phenomena that rely on spin-orbit coupling. These make possible the current induced motion of series of chiral domain walls at high speeds that exceed 1,000 m/s in atomically engineered synthetic antiferromagnetic racetracks. The same type of Dzyaloshinskii-Moriya exchange interactions that stabilize chiral Néel domain walls in such racetracks also enable the formation of topological spin textures such as spin helices and skyrmions. Recently we have discovered magnetic antiskyrmions and elliptical Bloch skyrmions in a family of tetragonal Heusler compounds. These magnetic nano-objects have unique properties that make them highly attractive as potential storage elements in racetrack memories. Finally, we discuss our recent discovery of fractional skyrmions and anti-skyrmions.
Host: Sang Cheong
Prof. Dr. Stuart Parkin, Max Planck Institute for Microstructure Physics, Halle (Saale), Germany
Bio: Stuart Parkin is the Managing Director of the Max Planck Institute for Microstructure Physics, Halle, Germany, and an Alexander von Humboldt Professor, Martin Luther University, Halle-Wittenberg. His research interests include spintronic materials and devices for advanced sensor, memory, and logic applications, oxide thin-film heterostructures, topological metals, exotic superconductors, and cognitive devices. Parkin’s discoveries in spintronics enabled a more than 10000-fold increase in the storage capacity of magnetic disk drives. For his work that thereby enabled the “big data” world of today, Parkin was awarded the Millennium Technology Award from the Technology Academy Finland in 2014 (worth 1,000,000 Euro). Parkin is a Fellow/ Member of: Royal Society (London), Royal Academy of Engineering, National Academy of Sciences, National Academy of Engineering, German National Academy of Science - Leopoldina, Royal Society of Edinburgh, Indian Academy of Sciences, and TWAS - academy of sciences for the developing world. Parkin has received numerous awards including the American Physical Society International Prize for New Materials (1994); Europhysics Prize for Outstanding Achievement in Solid State Physics (1997); 2009 IUPAP Magnetism Prize and Neel Medal; 2012 von Hippel Award - Materials Research Society; 2013 Swan Medal - Institute of Physics (London); Alexander von Humboldt Professorship ? International Award for Research (2014); ERC Advanced Grant - SORBET (2015).