Various magnetic domain structures such as magnetic vortices and single domains are formed in nano-scale magnets, depending on their shape and size. The magnetic vortices, for example, have two degrees of freedom, i.e., polarity and chirality, and allow us to design an artificial magnetic lattice called “magnonic crystal” consisting of several magnetic vortices. These are expected to be next-generation magnetic memory and logic devices. We fabricate nano-scale magnets to experimentally study their fundamental static and dynamic magnetic properties. We also use nano-scale magnets to produce “pure spin current” which transfers no electric charges but only spin angular momentums. By injecting the pure spin current into non-magnetic metals and superconductors, we are able to observe various interesting phenomena such as the spin Hall effect, the spin injection induced magnetization reversal, and the spin accumulation. We aim to study and develop new types of spintronic devices using the spin injection techniques.
In near future, current electronics for information technologies are expected to encounter fundamental limits in terms of physical size and energy efficiency as a consequence of advanced miniaturization. Spintronics, utilizing the spin of electrons to convey information, is anticipated to offer further development as well as the solution to the above problem. We put our focus on the novel properties of such spins emerging particularly from the interaction among spins and nano-scale magnets.
Professor YoshiChika OTANI was born in Tokyo Japan. He obtained his B.Sc. (1984), M. Sc. (1986) and Ph. D. (1989) degrees from Keio University. He was a research fellow (1989-1991) at Physics Department of the Trinity College, University of Dublin, a researcher (1991-1992) at the Laboratore Louis Neel, CNRS. Then he was appointed to a research instructor (1992-1995) at the Department of Physics, Keio University, an associate professor at the Department of Materials Science, Graduate School of Engineering, Tohoku University, and a team leader (since 2002) of Nano-Magnetics Laboratory at FRS-RIKEN. Since 2002 he has also been appointed to a professor at ISSP University of Tokyo. He has been primarily working on experimental studies on spintronics such as magnetic and transport properties of nano-structured magnetic/non-magnetic (superconductive) hybrid systems including vortex dynamics confined in magnetic nano-disks.
Professor Otani is earnest about the research, he is also caring about his students like us, and is giving helpful suggestions. He is so generous that we can do research as we want to. I really appreciate that he gives a lot of opportunities to present the outcomes of the research at the conferences. In our laboratory, Professor Otani leads us to tackle many novel research topics in collaboration with other research groups. The collaborators are often the researchers in other countries and the interaction with those international researchers is very exciting. It may take long to make our research outcomes of use in our daily lives, but we are sure that they can change our future in several decades. Important is not what you have learned, but what you will learn and what you want to do here. We are looking forward to meeting and working together with you full of drive!
Yoshichika Otani Lab., Department of Advanced Materials Science,
Graduate School of Frontier Sciences, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8561, Japan