Dynamical simulations of charged soliton transport in conjugated polymers with the inclusion of electron-electron interactions

Abstract

We present numerical studies of the transport dynamics of a charged soliton in conjugated polymers under the influence of an external time-dependent electric field. All relevant electron-phonon and electron-electron interactions are nearly fully taken into account by simulating the monomer displacements with classical molecular dynamics and evolving the wave function for the pi electrons by virtue of the adaptive time-dependent density matrix renormalization group simultaneously and nonadiabatically. It is found that after a smooth turn on of the external electric field the charged soliton is accelerated at first up to a stationary constant velocity as one entity consisting of both the charge and the lattice deformation. An Ohmic region (6 mV/A</=E(0)</=12 mV/A) where the stationary velocity increases linearly with the electric field strength is observed. The relationship between electron-electron interactions and charged soliton transport is also investigated in detail. We find that the dependence of the stationary velocity of a charged soliton on the on-site Coulomb interactions U and the nearest-neighbor interactions V is due to the extent of delocalization of the charged soliton defect.