Band resonant tunneling in DNA molecules.

The charge migration process in DNA is subject to a lively debate among researchers at the moment. We have performed calculations on poly(G)-poly(C) DNA which substantiate a recent report indicating bandlike conduction for this particular form of DNA. Our results show that both guanine and cytosine give rise to conducting channels along the DNA strands. The conductivity results from the overlap of the pi orbitals along the base stacks. We also demonstrate that the measured increase of the threshold voltage with temperature in poly(G)-poly(C) DNA is the result of electron localization due to the structural disorder following high temperature.