TY - JOUR
T1 - Chirality-Induced Spin Selectivity in a Coarse-Grained Tight-Binding Model for Helicene
AU - Geyer, Matthias
AU - Gutierrez, Rafael
AU - Mujica, Vladimiro
AU - Cuniberti, Gianaurelio
N1 - Funding Information:
The authors thank Solmar Varela, Elena Diaz, Francisco Dominguez-Adame, and Arezoo Dianat for very fruitful discussions. This work is funded by the European Union (ERDF) and the Free State of Saxony via the ESF projects 100231947 and 100339533 (Young Investigators Group “Computer Simulations for Materials Design—CoSiMa”). G.C. acknowledges financial support from the Volkswagen Stiftung (grant nos. 88366). This work was partly supported by the German Research Foundation (DFG) within the Cluster of Excellence “Center for Advancing Electronics Dresden”. The authors acknowledge the Center for Information Services and High-Performance Computing (ZIH) at TU Dresden for computational resources.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/11/7
Y1 - 2019/11/7
N2 - Spin-dependent effects in helical molecular systems, leading to the so-called chirality-induced spin selectivity (CISS) effect, have strongly attracted the attention of the chemical and physical community over the past few years. A large amount of experimental material has been collected so far, and different theoretical approaches have been presented to rationalize the CISS effect. The problem is, however, still a subject of debate. We present a semianalytical coarse-grained atomistic description of the electronic structure of a simple helical molecule, including spin-orbit interactions. For reference, we consider helicene, which is a pure carbon-based helical system with no chiral centers, and which has been previously shown experimentally to display a CISS effect. Our model exploits perturbation theory and a Löwdin-like partitioning to obtain an effective Ï-πHamiltonian, where all coupling coefficients depend on the helical geometry and predefined Slater-Koster parameters. As a result, they can be explicitly computed, thus providing physically meaningful orders of magnitude. We further discuss the conditions under which a nonvanishing spin polarization can be obtained in the model. We expect that our approach will serve to bridge the gap between purely phenomenological model Hamiltonians and more advanced first-principles methodologies.
AB - Spin-dependent effects in helical molecular systems, leading to the so-called chirality-induced spin selectivity (CISS) effect, have strongly attracted the attention of the chemical and physical community over the past few years. A large amount of experimental material has been collected so far, and different theoretical approaches have been presented to rationalize the CISS effect. The problem is, however, still a subject of debate. We present a semianalytical coarse-grained atomistic description of the electronic structure of a simple helical molecule, including spin-orbit interactions. For reference, we consider helicene, which is a pure carbon-based helical system with no chiral centers, and which has been previously shown experimentally to display a CISS effect. Our model exploits perturbation theory and a Löwdin-like partitioning to obtain an effective Ï-πHamiltonian, where all coupling coefficients depend on the helical geometry and predefined Slater-Koster parameters. As a result, they can be explicitly computed, thus providing physically meaningful orders of magnitude. We further discuss the conditions under which a nonvanishing spin polarization can be obtained in the model. We expect that our approach will serve to bridge the gap between purely phenomenological model Hamiltonians and more advanced first-principles methodologies.
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U2 - 10.1021/acs.jpcc.9b07764
DO - 10.1021/acs.jpcc.9b07764
M3 - Article
AN - SCOPUS:85074425094
SN - 1932-7447
VL - 123
SP - 27230
EP - 27241
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 44
ER -