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SYDU: Dynamik von Ummagnetisierungsvorgängen

SYDU II: HV II

SYDU II.1: Invited Talk

Thursday, March 29, 2001, 10:00–10:30, S5.2

Switching Modes in Meso-Scale Patterned Structures — •Jacques Miltat, Gonçalo Albuquerque, and André Thiaville — Laboratoire de Physique des Solides, Université Paris-Sud & CNRS, ORSAY, France

Three main modes of magnetic switching may now be clearly identified in confined structures, namely wall motion & merging, precessional reversal and spin-injection induced switching. Based on numerical simulations, pictorial evidence will clearly reveal the difficulties potentially linked with the first mechanism, leading to a brief discussion of their nature. It will be shown next that precessional switching proves both energy efficient and safe in the sense that it is not prone to the generation of unwanted micromagnetic structures such as winding Néel walls and/or magnetization vortices. Precessional switching in magnetically soft thin film confined structures with regular shapes may be decomposed into two phases, a first phase dominated by rapid precession (100 ps range) and a second to be characterized by non-linear spin waves generation, interference and slow decay (ns range). Because of its fundamental nature, precessional switching proves little sensitive to edge roughness and/or corners rounding-off. Lastly, spin-injection remains an intriguing process. Because of the competition between the Œrsted field and spin-injection effects, it is restricted to nanostructures with widths well below the 100 nm range. Simulation results will be compared to the latest available experimental data.