2018 IEEE Distinguished Lecturer
Title:Spin Conversion Phenomena in Spintronics
Speaker:Yoshichika Otani
(University of Tokyo, Japan)
Time:2018. 09. 05 (Wed.) 10:30
Location:Delta Building R401
Abstract:
Since the discovery of giant magnetoresistance, spintronics research has been
evolving and has reached a new phase in which the concept of spin currents,
i.e., the flow of spin angular momenta, helps us understand various spintronics
phenomena. These include all the recently discovered conversion phenomena,
such as the direct and inverse spin Hall effects, spin Seebeck and Peltier
effects, spin pumping, and the inverse Faraday effect. More recently, Rashba
interfaces and the surface states of topological insulators were found to
exhibit the so-called Edelstein effect, in which spin-momentum locking
behavior brings about non-equilibrium spin accumulation.
These interface and surface effects thus provide an effective means of
interconversion among spin, charge, and heat currents. Most of the abovementioned
spin conversion phenomena take place at simple nanoscale
interfaces between two different types of materials (e.g., magnets, nonmagnets,
semiconductors, and insulators). These structures may enable us to
advance spin-mediated interconversion among physical entities such as
electricity, light, sound, vibration, and heat.
I will first give an introduction to the general spin-mediated spin-conversion
processes and then will focus on magneto-electric spin conversion in
conductive solids, including spin Hall effects and new conversion mechanisms:
Edelstein effects arising at Rashba interfaces and surface states of
topological insulators, as discussed in a recently published progress article.
Sponsored by IEEE Magnetics Society Taipei Chapter
Co-sponsored by National Tsing Hua University