Regensburg 2019 – wissenschaftliches Programm
MA 36.11: Vortrag
Mittwoch, 3. April 2019, 17:45–18:00, H53
Accurate and generalized formalism for spin-admixture parameter calculations — •Uday Chopra1,2, Shambhawi Shambhawi3, Sergei Egorov1,4, Jairo Sinova1, and Erik R. McNellis1 — 1Johannes Gutenberg University, Staudingerweg 7, Mainz, 55128 — 2Graduate School Material Science in Mainz, Staudingerweg 9, Mainz, 55128 Germany — 3Dept. of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Dr, Cambridge CB30AS — 4University of Virginia, Chemistry Department, McCormick Rd, Charlottesville, VA 22901 USA
The spin-admixture parameter, γ [1,2], is key to understanding spin-dynamics in molecules. It characterizes the influence of spin-orbit coupling (SOC) on spin-dynamics in virtually all models for molecular materials with the spin- up/down mixing in a SOC perturbed wave-function. The parameter governs the probability of spin-flip as the charge hops in a network of sites in an organic semiconductor. However, the quality of its current first-principles electronic structure theory formulation is severely limited by multiple approximations. We generalize this formulation to remove all of these flaws and demonstrate its accurate predicability of spin-relaxation in organic semiconductors. The resulting γ is straightforwardly computed, valid for vastly greater variations in target molecules and chemical composition, and more sensitive to aspects of geometric and electronic structure. We discuss this by highlighting trends in spin-admixture influenced by molecular design.  Z. G. Yu, Phys. Rev. B, 85, 115201 (2012).  Z. G. Yu, Phys. Rev. Lett, 106, 106602 (2011).