One question about the electrode effect on I-V

[fangyongxinxi]

Dear Sir,
I want to get a quantitative analysis of the I-V characteristics as a function of the wire length (configuration see attachment).
We know that the whole scattering region (the atomic line and the pyramid-like electrode) share the "bias". If we consider different wire length with a certain bias, can we say "when 1V applied, the conductance of 2 atoms wire is better than 3 atoms wire"?
Because I am not sure the whole "1V" is applied the same on the 2 and 3 atoms. For example, when "1V" applied on the 2 atoms wire, may be the pyramid-like electrode share 0.2V, only 0.8V on the 2 atoms wire; and when "1V" applied on the 3 atoms wire, may be the pyramid-like electrode share 0.5V, only 0.5V on the 3 atoms wire.

Thank you.

[Anders Blom]

In ATK 2008.10, the bias is always applied between the outer edges of the electrodes. Changes to the central region have no effect on this.

You can calculate which atoms that carry the voltage drop (at least if you use the DensityMatrix constraint, as discussed heavily on this Forum), but the total bias is always applied across the entire structure.