Dresden 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 31: Magnetization Dynamics III

MA 31.4: Vortrag

Mittwoch, 16. März 2011, 11:45–12:00, HSZ 403

Angular momentum conservation in ultrafast spin manipulation processes on magnetic nanoclusters — •Georg Lefkidis and Wolfgang Hübner — Kaiserslautern University of Technology and Research Center OPTIMAS, Germany

Ultrafast optical Λ processes have been shown to lead to coherent spin manipulation on magnetic nanostructures with a few magnetic centers [1-3]. Thus multicenter magnetic clusters allow exploiting spin dynamics for full-fledged logic functionalization [2]. To explain the angular momentum conservation during the spin-flip processes we propagate in time the intragap levels of a NiO cluster under the influence of a linearly polarized laser pulse [3]. Subsequently we calculate the induced time-dependent electric polarization in the material and Fourier-transform into the frequency regime while convoluting with a time-weighting function. This way we calculate the frequency- and time-dependent Stokes vector. Using quantum optics analysis we show how the coherently induced material polarization leads to angular-momentum exchange between the light and the irradiated NiO surface. We also predict a dynamic Kerr-effect, which provides a signature for monitoring spin-dynamics, by simply measuring the transient rotation and ellipticity of the reflected pump beam [1].

[1] G. Lefkidis, G. P. Zhang, and W. Hübner, Phys. Rev. Lett. 103, 217401 (2009).

[2] W. Hübner, S. Kersten and G. Lefkidis, Phys. Rev. B 79, 184431 (2009).

[3] G. Lefkidis and W. Hübner, Phys. Rev. B 76, 014418 (2007).