Environment effects on the electric conductivity of the DNA
arXiv:0906.4518 · doi:10.1088/0953-8984/21/33/335105
Abstract
We present a theoretical analysis of the environment effects on charge transport in double-stranded synthetic poly(G)-poly(C) DNA molecules attached to two ideal leads. Coupling of the DNA to the environment results in two effects: (i) localization of carrier functions due to the static disorder and (ii) phonon-induced scattering of the carrier between these localized states, resulting in hopping conductivity. A nonlinear Pauli master equation for populations of localized states is used to describe the hopping transport and calculate the electric current as a function of the applied bias. We demonstrate that, although the electronic gap in the density of states shrinks as the disorder increases, the voltage gap in the characteristics becomes wider. Simple physical explanation of this effect is provided.
8 pages, 2 figures, to appear in J. Phys.: Condens. Matter