Exciton transport at short times

Exciton transport at short times is studied for the model of Grover and Sibey. The transport is always wave-like, and is governed by the unrenormalized transfer integral appropriate to unclothed excitons. Comparison with the long-time transport confirms that clothing occurs within about 10 ps. The results are discussed in the light of recent work on the generalized exciton master equation. This gives initially wave-like transport whenever the initial exciton density matrix is diagonal, and its agreement with the present results supports the claim that it can treat short-time effects. Previous comparisons with the model of Grover and Sibey could be misleading because only the long-time behaviour was treated.