TY - JOUR
T1 - Influence of Electronic Structure Modeling and Junction Structure on First-Principles Chiral Induced Spin Selectivity
AU - Zöllner, Martin Sebastian
AU - Saghatchi, Aida
AU - Mujica, Vladimiro
AU - Herrmann, Carmen
N1 - Funding Information:
We would like to thank Markus Reiher, ETH Zurich, for helpful discussions, Michael Deffner, University of Hamburg, for technical support, and the high-performance computing centre at the University of Hamburg for computational resources. This work is supported by Deutsche Forschungsgemeinschaft (DFG) via the project “Structure-property relationships for spin-orbit effects in chiral molecules” (HE 5675/4-1). V.M. acknowledges a Fellowship from Ikerbasque, the Basque Foundation for Science.
Publisher Copyright:
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PY - 2020/12/8
Y1 - 2020/12/8
N2 - We have carried out a comprehensive study of the influence of electronic structure modeling and junction structure description on the first-principles calculation of the spin polarization in molecular junctions caused by the chiral induced spin selectivity (CISS) effect. We explore the limits and the sensitivity to modeling decisions of a Landauer/Green's function/two-component density functional theory approach to CISS. We find that although the CISS effect is entirely attributed in the literature to molecular spin filtering, spin-orbit coupling being partially inherited from the metal electrodes plays an important role in our calculations on ideal carbon helices, even though this effect cannot explain the experimental conductance results. Its magnitude depends considerably on the shape, size, and material of the metal clusters modeling the electrodes. Also, a pronounced dependence on the specific description of exchange interaction and spin-orbit coupling is manifest in our approach. This is important because the interplay between exchange effects and spin-orbit coupling may play an important role in the description of the junction magnetic response. Our calculations are relevant for the whole field of spin-polarized electron transport and electron transfer, because there is still an open discussion in the literature about the detailed underlying mechanism and the magnitude of physical parameters that need to be included to achieve a consistent description of the CISS effect: seemingly good quantitative agreement between simulation and the experiment can be caused by error compensation, because spin polarization as contained in a Landauer/Green's function/two-component density functional theory approach depends strongly on computational and structural parameters.
AB - We have carried out a comprehensive study of the influence of electronic structure modeling and junction structure description on the first-principles calculation of the spin polarization in molecular junctions caused by the chiral induced spin selectivity (CISS) effect. We explore the limits and the sensitivity to modeling decisions of a Landauer/Green's function/two-component density functional theory approach to CISS. We find that although the CISS effect is entirely attributed in the literature to molecular spin filtering, spin-orbit coupling being partially inherited from the metal electrodes plays an important role in our calculations on ideal carbon helices, even though this effect cannot explain the experimental conductance results. Its magnitude depends considerably on the shape, size, and material of the metal clusters modeling the electrodes. Also, a pronounced dependence on the specific description of exchange interaction and spin-orbit coupling is manifest in our approach. This is important because the interplay between exchange effects and spin-orbit coupling may play an important role in the description of the junction magnetic response. Our calculations are relevant for the whole field of spin-polarized electron transport and electron transfer, because there is still an open discussion in the literature about the detailed underlying mechanism and the magnitude of physical parameters that need to be included to achieve a consistent description of the CISS effect: seemingly good quantitative agreement between simulation and the experiment can be caused by error compensation, because spin polarization as contained in a Landauer/Green's function/two-component density functional theory approach depends strongly on computational and structural parameters.
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U2 - 10.1021/acs.jctc.0c00621
DO - 10.1021/acs.jctc.0c00621
M3 - Article
C2 - 33167619
AN - SCOPUS:85096511171
SN - 1549-9618
VL - 16
SP - 7357
EP - 7371
JO - Journal of Chemical Theory and Computation
JF - Journal of Chemical Theory and Computation
IS - 12
ER -