Dresden 2009 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 13: Thin Films and Nanostructures I

DF 13.7: Talk

Wednesday, March 25, 2009, 16:40–17:00, WIL B321

Design of nanostructures with maximal magnetoresistance using genetic algorithms — •daungruthai jarukanont — University of Kassel, Kassel, Germany

Spintronics, or spin electronics, involves the study of active control over spin degrees of freedom in solid-state systems. In the field of molecular-electronics, one attempts to make electronic devices using organic molecules. Traditionally these two areas have lived separate lives. Recently experiments have indicated a possible pathway towards their integration. In molecular-spintronics, the spin-polarized currents are carried through molecules, and these can affect the state of the molecule. We study the system of an organic molecule between two ferromagnetic electrodes. The calculations are based on the non-equilibrium Green's function and the Keldysh formalism for the tight-binding Hamiltonian. We show that organic spin valves can exhibit a bias-dependent magnetoresistance(MR). The magnitude of MR depends on the details of the molecules. These will allow us to suggest an appropriate choice for molecules for molecular-spintronics devices. However since the number of organic molecules that are available is enormous, it is currently very difficult to predict which molecules would be suitable for such devices. We perform a Genetic Algorithm to optimize the magnitude of MR and determine the appropriate molecular choices.