Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 32: Surface Magnetism and Spin Phenomena
O 32.2: Poster
Dienstag, 17. März 2015, 18:15–21:00, Poster A
Spin-resolved electron transmission through chiral films on metal surfaces — •Matthias Kettner1, Benjamin Göhler1, Debabrata Mishra2, Georg F. Hanne2, Ron Naaman2, and Helmut Zacharias1 — 1Physikalisches Institut, Universität Münster, Germany — 2Department of Chemical Physics, Weizmann Institute, Rehovot, Isreal
The increasing interest in sources for spin polarized electrons for spintronic applications leads to new approaches, including interaction of electrons with chiral molecules. Experiments on self-assembled monolayers of DNA indicated a spin-filtering behavior of the molecules [1].
In our experiments the samples, kept at room temperature, are irradiated with 213nm laser radiation to generate photoelectrons from metal substrates covered with various chiral thin films. These electrons transmit the chiral film and are analyzed by a Mott polarimeter. It can be shown that due to the interaction of the photoelectrons within the films electrons are spin-filtered. Longitudinal spin polarizations up to 57% can be measured in case of double stranded DNA even by irradiation with linearly polarized light [2]. Experiments with other chiral molecules, namely membrane proteins and self-assembled monolayers of α-helical polypeptides show similar electron spin filtering properties [3]. Furthermore a dependence of the spin polarization on the length of the molecules is measured.
S.G. Ray et al., PRL 96, 036101 (2006)
B. Göhler et al., Science 331, 894 (2011)
D. Mishra et al., PNAS 110, 14872 (2013)