Polaron tunneling dynamics in the DNA molecule

摘要

The formation of polaron and its migration in a DNA chain are studied withina semiclassical Peyrard-Biship-Holstein polaron model. Comparing the energeticsof the polaron system found from the quantum chemical and semiclassicalcalculations, we extract the charge-phonon coupling constant for poly DNAsequences. The coupling constant is found to be larger for the G-C than for theA-T pairs. With this coupling constant we study tunneling in the DNA molecule.The rates and the nature of tunneling have strong dependence on the DNAsequence. By changing the trap positions in the molecular bridge the tunnelingrate can by varied up to seven orders of magnitude.