Hi again,
But now my question it seems about Kwant's functional, i.e. is it possible to calculate with it the transmission (in the sense of probability) through the barrier (single and double)? So, if the Landauer's formula gives the conductivity as G=2e^2/h * T(E) * M(E) (for zero temperature), where M is the number of opened modes, and T is the transparency, in my present understanding, Kwant calculates somewhat like T(E) * M(E),
I would be hesitant to write the transmission is such a form because the meaning of the T(E) that you have defined above is not clear in the case that, for example, different modes have different transmission probabilities. However I would conceded that, yes, 'smatrix.transmission' calculates more or less 'T(E) * M(E)'.
but can it give me just T(E)?
Sure. 'kwant.smatrix' will return you the full scattering matrix at the energy you request. It has a method 'submatrix' that will give you a submatrix of the full scattering matrix between any pair of leads, e.g.: s = kwant.smatrix(syst, energy=E) t = s.submatrix(1, 0) # transmission block from lead 0 to lead 1 T = np.abs(t)**2 # transmission *probabilities* You can find more information in the documentation [1]. Happy Kwanting, Joe [1]: https://kwant-project.org/doc/1.0/reference/generated/kwant.solvers.common.S...