Regensburg 2019 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 49: Metal Substrates III: Structure, Epitaxy and Growth
O 49.4: Vortrag
Mittwoch, 3. April 2019, 11:15–11:30, H5
Helical interdigitation of alpha-L polyalanine investigated by ambient STM — •Nguyen Thi Ngoc Ha1, Yossil Patilte2, and Christoph Tegenkamp1,3 — 1Technische Universitaet Chemnitz — 2Department of Applied Physics, Hebrew University of Jerusalem, Israely — 3Leibniz Universitaet Hannover, Germany
Polyalanine (PA) has an alpha-helix conformation, which is maintained by hydrogen bonds formed by backbone N-H and C=O groups of the amino acid located three or four residues earlier along the protein sequence. PA has gathered recently a lot of interest as the propagation of electrons along the helical backbone structure comes along with spin polarization of the transmitted electron. Self-assembly of PA molecules on HOPG substrate form two types of hexagonal structures: after showing a hexagonal structure with a next-neighbor distance of around 2.0nm, finally a well-ordered structure with closer lattice parameter (1.2nm) is found. This closed package structure is formed by the interdigitating between adjacent PA molecules due to the formation of additional hydrogen bonds from their helical back-bones and can be kinetically controlled by increasing the deposition tem- perature. The ordering within helical film refers to new ordering mechanism and can most likely explain the coherence in the electronic transport and high efficiency for the current induced spin selectivity[1] [1] R. Naaman, D. H. Waldeck, Annu. Rev. Phys. Chem. 66, 263-81, 2015.