Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 30: Spin-Dynamics / Spin-Torque III

MA 30.4: Vortrag

Donnerstag, 26. März 2009, 11:00–11:15, HSZ 04

Time-Resolved Imaging and Modeling of Oscillations of a Single Magnetic Domain Wall — •Lars Bocklage¹, Benjamin Krüger², René Eiselt¹, Markus Bolte¹, Peter Fischer³, and Guido Meier¹ — ¹Institut für Angewandte Physik, Universität Hamburg — ²I. Institut für Theoretische Physik, Universität Hamburg — ³Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California

Current-induced magnetization dynamics are an intersting field of research. Domain walls and vortices can be moved by spin-polarized currents. We image oscillations of a single domain wall in a confining potential in time steps of 200 ps by time resolved x-ray microscopy with a spacial resolution of 25 nm and a temporal resoution of 70 ps [1]. The oscillation of the domain wall is triggered by nanosecond current pulses. The spin-polarized current and the accompanied Oersted field can contribute to the motion of the wall. An analytical model of a rigid particle precisely describes the domain-wall motion. From the observed oscillations we extract the confining potential, the driving force, the domain-wall mass, and the damping parameter of permalloy. Higher than harmonic terms determine the motion of the wall. By looking at various phase spaces the influence of these nonharmonic contributions are studied.
This work was supported by DOE BES, SFB 668 and GrK 1286.
L. Bocklage, B. Krüger, R. Eiselt, M. Bolte, P. Fischer, and G. Meier, PRB 78, 180405(R) (2008)