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