Chirality-induced spin selectivity is a recently-discovered effect, which results in spin selectivity for electrons transmitted through chiral peptide monolayers. Here, we use this spin selectivity to probe the organization of self-assembled α-helix peptide monolayers and examine the relation between structural and spin transfer phenomena. We show that the α-helix structure of oligopeptides based on alanine and aminoisobutyric acid is transformed to a more linear one upon cooling. This process is similar to the known cold denaturation in peptides, but here the self-assembled monolayer plays the role of the solvent. The structural change results in a flip in the direction of the electrical dipole moment of the adsorbed molecules. The dipole flip is accompanied by a concomitant change in the spin that is preferred in electron transfer through the molecules, observed via a new solid-state hybrid organic-inorganic device that is based on the Hall effect, but operates with no external magnetic field or magnetic material.
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We acknowledge the help of Dr Anup Kumar in performing the ellipsometry measurements. ME, EC, SM and RN acknowledge the support by the ERC-Adv grant and the Isreal Science Foundation. RN and YP acknowledge the support of the VW Foundation and the Israel Ministry of Science. SRA, SS and LK acknowledge support by the European Research Council, the Israel Science Foundation and the Lise Meitner Center for Computational Chemistry. SRA acknowledges an Adams Fellowship of the Israel Academy of Sciences and Humanities.