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MA: Fachverband Magnetismus
MA 8: Magnetic Surface Excitations
MA 8.9: Talk
Monday, March 7, 2016, 17:15–17:30, S052
Enantiomer-dependent spin orientation in photoelectron transmission through heptahelicene molecules — •Matthias Kettner1, Johannes Seibel2, Daniel Nürenberg1, Karl-Heinz Ernst2, and Helmut Zacharias1 — 1University of Münster, Center for Soft Nanoscience and Physikalisches Institut, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany — 2EMPA, Nanoscale Materials Science, Überlandstrasse 129, 8600 Dübendorf, Switzerland
The interaction of electrons with helical molecules attains growing interest due to a spin selectivity in electron transmission. Experiments on self-assembled monolayers of double stranded DNA and oligopeptides [1] indicated a very efficient spin filtering behavior of the molecules at room temperature.
In present experiments enantiopure M- and P-heptahelicene molecules are evaporated onto different metal single crystal surfaces. The molecules arrange themselves to a highly ordered monolayer [2]. Samples are then irradiated with λ = 213nm laser radiation to generate photoelectrons from the substrate. These electrons are transmitted through the heptahelicene layer and analyzed with regard to their average longitudinal spin orientation by Mott scattering. The sign of the spin polarization depends on the helicity of the enantiomer. The effect of the heptahelicene on the spin orientation seems to be independent on the substrate.
References
[1] Kettner, M. et al., J.Phys.Chem. C 2014, 119, 26
[2] Seibel, J. et al., J.Phys.Chem. C 2014, 118, 29135