TUD

By merging DFTB calculation and model-Hamiltonian approaches, we study the stretching-twisting process of poly(GC) DNA. A local maximum of hopping parameter t between two nearest-neighbor GC pairs is found in over-stretching process, which is due to the competition between stretching and twisting. This will lead to a local maximum of current in the case that \Gamma is greater than t. Reducing \Gamma to the case that it is greater than t in some area of the stretching-twisting process and less than t in the other area, we will get the plateau for the current in the region \Gamma < t, and the heights of plateaus are almost equal to each other.