Environmental Effect on the Relative Contribution of the Charge-Transfer Mechanisms within a Short DNA Sequence

Abstract

Time evolution of the charge-transfer site population is studied in a short DNA sequence to determine the type of governing charge-transfer mechanism. The system consists of a 5'-GAGGG-3' nucleobase sequence coupled with a dissipative bath that represents the DNA phosphate backbone and solvents. Relative contribution of transfer mechanisms to the whole charge-transfer process has been obtained using the on-the-fly filtered propagator functional path integral method with the density matrix decomposition. Partial density matrixes of the incoherent hopping and coherent superexchange pathways as well as the full reduced density matrix have been evaluated and discussed for both debye and ohmic baths. It was found that the relative contribution of the transfer mechanisms is rather sensitive to the frequency-dependent environmental description.