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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 33: Molecular Structure

CPP 33.2: Talk

Thursday, February 28, 2008, 15:15–15:30, C 230

Dipole switching in extended molecular systems: Explicitly time-dependent configuration interaction simulations — •Tillmann Klamroth and Pascal Krause — Institut für Chemie, Theoretische Chemie, Universität Potsdam

We perform laser-driven charge transfer simulations for Li-(Ph)_n-CN (n=1,2,3) using the TD-CIS (Time-Dependent Configuration Interaction Singles)[1] approach. These molecules serve as systematically extendable model systems. The selectivity, and thus controllability, of an ultra-short laser-induced electronic excitation as a function of the molecular size is investigated. For example, such control may be needed if a small electronic molecular switch is embedded in a larger molecular device.

Using the TD-CIS method within the fixed nuclei approximation, ultra-short π-pulses are employed in order to induce a charge transfer transition. We show that for certain pulse widths the selectivity is lost mainly due to multi-photon transitions and dynamic polarizations of the molecules. The latter processes depends systematically on the molecular size, i.e. it gets more important for larger molecules.

[1] T. Klamroth, Phys. Rev. B 68, 245421 (2003); P. Krause, T. Klamroth, P. Saalfrank, J. Chem. Phys. 123, 074105 (2005); T. Klamroth, J. Chem. Phys.124, 144310 (2006).