NCTS (South)


DATE2015-03-02

TIME14:00

PLACE物理二館地下室 (49X04)

FIELDOther

SPEAKER 莊子弘 - RIKEN SPring-8 Center, Japan

TITLEHigh wave-vector magnon excitations in low-dimensional ferromagnets

ABSTRACTFirst, a combined experimental and theoretical study of the interplay between the atomic structure and the magnon excitations in low-dimensional ferromagnets is presented. First-principles calculations confirm the experimental results revealing a strong dependency of exchange interactions on the atomic structure. Our results suggest a way of tailoring magnetic excitations in low-dimensional magnetic structures. Second, we propose a method for probing the magnetic exchange interaction at buried interfaces using spin-polarized electrons and taking advantage of the collective nature of elementary magnetic excitations (magnons). We demonstrate that, for the case of weak coupling at the interface, the low-energy magnon mode is mainly localized at the interface. The comparison of experimental data and first-principles calculations leads to the determination of the interface exchange parameters. This method may help the development of spectroscopy of buried magnetic interfaces.