Dynamics of charge propagation on molecular circuits

We report molecular dynamics results of charge propagation in molecular cir cuits build from branching off conjugated polymers. The low-lying particle- like excitations are found to be solitons. A 2-d tight-binding Hamiltonian is used to model the conjugated polymers with a bifuraction. It is found th at the soliton can be trapped, can go through, or be reflected on the bifur cation depending on the single-double bond configuration at the bifurcation site as well as the length of each of the branches. In particular, a benze ne ring impedes the soliton crossing. (C) 1999 Elsevier Science B.V. All ri ghts reserved.