Fig. 5.

The DOS, the energy-dependent localization length (${\ell }_{\text{loc}}$), and the transmission for a duplex DNA composed of G–C base pairs. A illustrates the model Hamiltonian in Eq. 5. The parameters used for the calculation are all described below Eq. 5. B shows the DOS and ${\ell }_{\text{loc}}\left(E\right)$ for a chain with only the first five HOMO states in each site. The localization length grows with increasing electron or hole energy. Correspondingly, the transmission probability of a hole injected at energy $E=100$ meV decays exponentially with length in the absence of an electric field (C). The length dependence of the probability changes to a power law when an electric field is applied, as in the single-orbital case (Fig. 2).