Regensburg 2010 – wissenschaftliches Programm
MA 18.4: Vortrag
Mittwoch, 24. März 2010, 16:00–16:15, H3
Energy and angle dependent threshold photoemission magnetic circular dichroism from an ultrathin Co/Pt(111) film — •Kerstin Hild1, Gerd Schönhense1, Hans-Joachim Elmers1, Takeshi Nakagawa2, Toshihiko Yokoyama2, and Peter Oppeneer3 — 1Institut für Physik, Johannes Gutenberg-Universität Mainz, Germany — 2Institute for Molecular Science, The Graduate University for Advanced Studies Okazaki, Japan — 3Department of Physics and Materials Science, Uppsala University, Sweden
Threshold photoemission magnetic circular dichroism (TPMCD) has recently been observed in one- and two- photon photoemission (1PPE  and 2PPE ). We report on measurements for ultrathin Co films with perpendicular magnetization grown on Pt (111) using ultrashort pulse lasers. Energy dependent TPMCD measurements reveal asymmetries, continuously increasing when approaching the photo threshold. At the threshold we obtain maximum values of 1.90 % for 1PPE and 12.8 % in the case of 2PPE. Angle dependent TPMCD measurements result in reduced asymmetry values for large incident angles following a cosine law in the case of 2PPE. The measured TPMCD asymmetries are compared to theoretical predictions based on local spin density calculations.
Funded by Carl-Zeiss-Stiftung and the Graduate School of Excellence MAINZ (Kerstin Hild)  T. Nakagawa and T. Yokoyama, Phys. Rev. Lett. 96, 237402 (2006).  K. Hild et al., Phys. Rev. Lett. 102, 057207 (2009).