Berlin 2008 – scientific programme
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MA: Fachverband Magnetismus
MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)
MA 32.64: Poster
Friday, February 29, 2008, 11:15–14:00, Poster E
Brillouin light scattering microscopy on magnetization dynamics in spin torque nanocontacts — •Sebastian Hermsdörfer1, Xavier Janssens2, Sven Cornelissen2, Maarten van Kampen2, Helmut Schultheiß1, Britta Leven1, Andrei N. Slavin3, Liesbet Lagae2, and Burkard Hillebrands1 — 1Fachbereich Physik and FSP MINAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany — 2IMEC, Kapeldreef 75, Leuven, Belgium — 3Oakland University, Rochester, Michigan, USA
Here we report on investigations of the magnetization dynamics in spin-torque nanocontacts under the influence of an applied ac and dc current. The magnetic resonances are determined with Brillouin light scattering microscopy for different externally applied magnetic fields. For the observed resonance frequencies the spin-wave radiation patterns are studied with high spatial resolution. Furthermore, nonlinear effects are observed and can be explained by three-magnon-scattering. A shift of the power threshold for these nonlinear processes is observed when a dc current is applied in addition to the ac current. We demonstrate that the threshold and efficiency of the three-magnon-scattering can be strongly enhanced or reduced depending on the direction of the dc current. This is clear evidence that internal damping due to magnon scattering can be tuned by a dc current. Support by the DFG within the SPP 1133 and by the EC-MRTN SPINSWITCH (MRTN-CT-2006-035327) and EC-Dynamax (IST-033749) is acknowledged. MvK acknowledges the IWT Flanders for financial support.