Nonadiabatic simulations of polaron dynamics

Polaron drift in an external electric field and the dynamics following insertion of an electron have been simulated in a one-dimensional conjugated polymer chain. The simulations were performed by solving the time-dependent Schr\"odinger equation and the lattice equation of motion simultaneously and nonadiabatically. We observed a step-like transition from sonic to supersonic polaron velocities around a field strength of 0.140.3em0exmV∕. This behavior is observed to be directly related to decoupling of the acoustic and optical characters of the lattice vibrations associated with the polaron. Thermalization of hot (excited) electrons was shown to occur at a subpicosecond time scale. This process is highly nonadiabatic and strongly coupled to the lattice vibrations.