Effect of the electric field mode on the dynamic process of a polaron

Transport process of a charged polaron under a linearly increasing electric field in conjugated polymers is investigated by using a nonadiabatic evolution method. It is found that the behavior of a polaron depends not only upon the strength of the field but also upon the mode of the application of the field. A polaron can conserve even under a strong field if the field is applied slowly. The result is compared with that of the adiabatic approximation and it is obtained that the nonadiabatic critical time is much larger than the adiabatic value. Dependence of the applying mode of the external electric field on the polaron dissociation and the transition of its velocity from the subsonic to supersonic value are further described.