Hi Lorenzo, You need to compute the transmission at an energy where the leads have modes. At E = 10 in your system there aren't any.
Plotting the band structure of the leads helps. Check out also the Kwant tutorial at https://kwant-project.org/doc/1/tutorial/ Best, Anton On Tue, 18 Jan 2022 at 15:37, Lorenzo BAGNASACCO <lorenzo.bagnasa...@sns.it> wrote: > Dear Kwant community, > > I am a physics student and I am approaching to Kwant to solve simple > problems of scattering. > I am new in Kwant and, for this reason, I'm trying to use Kwnat for basic > problems of scattering. > The most simple problem in my mind is the scattering of a plane-wave (1 > dimension) from the left of a potential barrier. If we now suppose the > potential barrier is 'zero' everywhere, the scattering matrix, according to > the scattering theory, should be 'S={{0,1},{1,0}}'. > If I try to compute the reflection and transmission coefficient, I > obtained the correct values (1 for reflection and 0 for transmission). But > it occurs only for some energies. For example in the code I attached, if I > put the value of '10' in 'S=kwant.solvers.default.smatrix(syst,10)' I > obtaine for reflection and transmission the value of '0'. Where is my > errors? And, is there a way to print the entire elements of the scattering > matrix ? > > Yours sincerely > > Lorenzo Bagnasacco > >
