| Autor: |
Zöllner MS; Department of Chemistry, University of Hamburg, 20146 Hamburg, Germany., Varela S; School of Chemical Sciences and Engineering, Yachay Tech University, 100119 Urcuquı́, Ecuador., Medina E; Yachay Tech University, School of Physical Sciences and Nanotechnology, 100119 Urcuquı́, Ecuador., Mujica V; School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, USA., Herrmann C; Department of Chemistry, University of Hamburg, 20146 Hamburg, Germany. |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of chemical theory and computation [J Chem Theory Comput] 2020 May 12; Vol. 16 (5), pp. 2914-2929. Date of Electronic Publication: 2020 Apr 22. |
| DOI: |
10.1021/acs.jctc.9b01078 |
| Abstrakt: |
The chiral-induced spin selectivity (CISS) effect, which describes the spin-filtering ability of diamagnetic structures like DNA or peptides having chiral symmetry, has emerged in the past years as the central mechanism behind a number of important phenomena, like long-range biological electron transfer, enantiospecific electrocatalysis, and molecular recognition. Also, CISS-induced spin polarization has a considerable promise for new spintronic devices and the design of quantum materials. The CISS effect is attributed to spin-orbit coupling, but a sound theoretical understanding of the surprising magnitude of this effect in molecules without heavy atoms is currently lacking. We are taking an essential step into this direction by analyzing the importance of imaginary terms in the Hamiltonian as a necessary condition for nonvanishing spin polarization in helical structures. On the basis of first-principles calculations and analytical considerations, we perform a symmetry analysis of the key quantities determining transport probabilities of electrons of different spin orientations. These imaginary terms originate from the spin-orbit coupling, and they preserve the Hermitian nature of the Hamiltonian. Hence, they are not related to the breaking of time-reversal symmetry resulting from the fact that molecules are open systems in a junction. Our symmetry analysis helps to identify essential constraints in the theoretical description of the CISS effect. We further draw an analogy with the appearance of imaginary terms in simple models of barrier scattering, which may help understanding the unusually effective long-range electron transfer in biological systems. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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