Temperature effect on polaron dynamics in DNA molecule: The role of electron-base interaction

摘要

We investigate the effect of temperature on polaron dynamics in the framework of a tight-binding model. Polaron stability at a finite temperature is studied at first. The dissociation of a polaron becomes fast with the increase of temperature. There exists a crossover of the charge localization time from strong to weak temperature dependence. The polaron motion under a driven field is also studied. It is found that a high temperature will result in a fast movement of a polaron under a driving field, which indicates that the polaron motion is thermally activated. Thus, DNA conductivity is considered to be increased with the increase of temperature, which is coincident to recent experimental findings. The effect of electron-base (e-b) interactions is also studied. It is found that the increase of either local or non-local e-b interaction can lead to a long time charge localization and a slow movement of a polaron.