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아 래
1. 제 목: Wave properties of dipole-exchange spin waves in confined magnetic thin films
2. 연 사: 김 상 국 교수(서울대 신소재공학과)
3. 일 시: 2006년 10월 25일(수요일) 오후 430
4. 장 소: 물리학과세미나실(31355호실)
5. 초 록: Dipole-exchange spin waves in confined ferromagnetic thin-film structures have attracted
much attention because of their fundamental interests as well as technological applications to
magnetic logic and sensor devices [1]. Accordingly, studies on the eigenmodes of spin-wave
excitations have been intensively performed both theoretically and experimentally for quasi-two-
dimensional micrometer-size films with various shapes. However, those spin waves have not been
studied in terms of its wave behaviors, such as radiation, propagation, transmission, reflection, and
interference. In this talk, I will present micromagnetic simulation results on the characteristic wave
properties of spin waves traveling in various model systems made of geometrically confined magnetic
films [2]. It is found that strong spin waves can be radiated from the core of a single magnetic vortex
by virtue of large torques localized at the core region, and that the radiated spin waves can be
injected into and propagate well through variously shaped nanowire-type magnetic waveguides.
Furthermore, their transmission through heterostructures, and its related filtering of spin waves with
lower frequencies are investigated. Finally, spin-wave interference is demonstrated with a model
system, which is analogous to Young’s double slit experiment with light. These results offer a preview
of the forthcoming era of magnetic logic devices using spin waves traveling at ultrahigh speeds [3, 4].