SPring-8, the large synchrotron radiation facility

Date & Time: April 12, 2005, 16:00-17:00

Speaker: Prof. Burkard Hillebrands
Affiliation: Fachbereich Physik, Technische Universität Kaiserslautern

Abstract
　　For applications in sensors and in data storage, the dynamic properties of micro- and nanostructures gain increasing attendance. The fundamental excitations in these objects are confined spin waves, and it is useful in particular to understand their properties in view of the noise spectrum in sensor and MRAM applications.
　　The lecture addresses the dynamics in homogeneously and inhomogeneously magnetized objects starting with an introduction into spin waves and the effects of finite dimensions. In inhomogeneous systems the excitation spectrum is complex, and new phenomena, like localization and tunneling of modes are discussed. The key points are illustrated by results obtained by space- and time-resolved Brillouin light scattering technique, which allows one to follow experimentally the propagation of spin wave packets and to present the results in an animated format. To conclude the lecture, the analysis of ultra-high frequency dynamic properties (2-100 GHz) of small magnetic elements with spatial resolution in the 300 nanometer range is presented.