Berlin 2008 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 14: Transport: Nanoelectronics III - Molecular Electronics

TT 14.3: Vortrag

Dienstag, 26. Februar 2008, 10:00–10:15, H 3010

Dynamical effects in the conductance properties of short DNA molecular wire: a combined study using molecular dynamics and model Hamiltonians — •Rodrigo Caetano¹, Rafael Gutierrez¹, Ben Woiczikowski², Tomas Kubar², Marcus Elstner², and Gianaurelio Cuniberti¹ — ¹Institute for Materials Science and Max Bergmann Center for Biomaterials, Dresden University of Technology, D-01062 Dresden, Germany — ²Institute for Physical and Theoretical Chemistry, Braunschweig University of Technology, D-38106 Braunschweig, Germany

The potential applications of DNA either as template or as molecular wires make of crucial importance to understand the microscopic mechanism leading supporting (or hindering) charge migration through this molecule. The experimental studies give very striking results, which range from insulating up to superconducting behavior. Theoretically, it is very important to include dynamical effects, since DNA is known to be a very flexible molecule. The dynamical effects of the solvent should be taken into account. In this work, we study charge transport through short Poly(G)-Poly(C) DNA within a minimal tight binding model. The model parameters are extracted from snapshots along QM/MM trajectories via DFTB approximation and thus include internal and solvent dynamical effects. We perform a statistical analysis of the time-dependent onsite and electronic hopping and show a broad non symmetric distribution. Green function formalism is used to calculate the transport characteristics and demonstrate how the average quantities depend on the relation between system time scales.