TY - JOUR
T1 - Enhanced Magnetoresistance in Chiral Molecular Junctions
AU - Maslyuk, Volodymyr V.
AU - Gutierrez, Rafael
AU - Dianat, Arezoo
AU - Mujica, Vladimiro
AU - Cuniberti, Gianaurelio
N1 - Funding Information:
We thank H. Zacharias for very useful discussions. R.G., V.M., and G.C. acknowledge financial support from the Volkswagen Stiftung (Grant 88366). This work was partly supported by the German Research Foundation (DFG) within the Cluster of Excellence “Center for Advancing Electronics Dresden”. We acknowledge the Center for Information Services and High Performance Computing (ZIH) at TU Dresden for computational resources. V.M. acknowledges financial support from the DRESDEN Fellowship Programme.
Publisher Copyright:
Copyright © 2018 American Chemical Society.
PY - 2018/9/20
Y1 - 2018/9/20
N2 - Chirality-induced spin selectivity (CISS) is a recently discovered effect, whose precise microscopic origin has not yet been fully elucidated; it seems, however, clear that spin-orbit interaction plays a pivotal role. Various model Hamiltonian approaches have been proposed, suggesting a close connection between spin selectivity and filtering and helical symmetry. However, first-principles studies revealing the influence of chirality on the spin polarization are missing. To clearly demonstrate the influence of the helical conformation on the spin polarization properties, we have carried out spin-dependent Density-Functional Theory (DFT) based transport calculations for a model molecular system. It consists of α-helix and β-strand conformations of an oligo-glycine peptide, which is bonded to a nickel electrode and to a gold electrode in a two-terminal setup, similar to a molecular junction or a local probe, for example, in STM or AFM configurations. We have found that the α-helix conformation displays a spin polarization, calculated through the intrinsic magneto-resistance of the junction, about 100-1000 times larger than the linear β-strand, clearly demonstrating the crucial role played by the molecular helical geometry on the enhancement of spin polarization associated with the CISS effect.
AB - Chirality-induced spin selectivity (CISS) is a recently discovered effect, whose precise microscopic origin has not yet been fully elucidated; it seems, however, clear that spin-orbit interaction plays a pivotal role. Various model Hamiltonian approaches have been proposed, suggesting a close connection between spin selectivity and filtering and helical symmetry. However, first-principles studies revealing the influence of chirality on the spin polarization are missing. To clearly demonstrate the influence of the helical conformation on the spin polarization properties, we have carried out spin-dependent Density-Functional Theory (DFT) based transport calculations for a model molecular system. It consists of α-helix and β-strand conformations of an oligo-glycine peptide, which is bonded to a nickel electrode and to a gold electrode in a two-terminal setup, similar to a molecular junction or a local probe, for example, in STM or AFM configurations. We have found that the α-helix conformation displays a spin polarization, calculated through the intrinsic magneto-resistance of the junction, about 100-1000 times larger than the linear β-strand, clearly demonstrating the crucial role played by the molecular helical geometry on the enhancement of spin polarization associated with the CISS effect.
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U2 - 10.1021/acs.jpclett.8b02360
DO - 10.1021/acs.jpclett.8b02360
M3 - Article
C2 - 30188726
AN - SCOPUS:85053719884
SN - 1948-7185
VL - 9
SP - 5453
EP - 5459
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 18
ER -