Excited state dynamics in DNA double helices

Eric R. Bittner

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arXiv · cond-mat/0606333

Excited state dynamics in DNA double helices

Eric R. Bittner

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Abstract

Recent ultrafast experiments have implicated that intrachain base-stacking rather than base-pairing mediate the fate and transport of photoexcited species in DNA chains. Here use an $SU(2)\otimes SU(2)$ lattice model which incorporates both intrachain and interchain electronic interactions to study the quantum mechanical evolution of an initial excitonic state placed on either the adenosine or thymidine side of a model B DNA poly(dA).poly(dT) duplex. Our calculations indicate that over several hundred femtoseconds, the adenosine exciton remains a cohesive excitonic wave packet on the adenosine side of the chain where as the thymidine exciton rapidly decomposes into mobile electron/hole pairs along the thymidine side of the chain. In both cases, the very little transfer to the other chain is seen over the time-scale of our calculations. We attribute the difference in these dynamics to the roughly 4:1 ratio of hole vs. electron mobility along the thymidine chain.

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Eric R. Bittner. 2006-06-14. Excited state dynamics in DNA double helices. https://arxiv.org/abs/cond-mat/0606333

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