Dear Kwant community,
Thanks for the quick reply. I plot the band structure and I obtaine the figure I attached. For a free-particle I expect a band structure like quadratic dispersion (E \sim k^2). The plot of structure band is nearly quadraic. Is it due to discretization of the system ? So it means that the wave-function sent to the left lead (in my example) is not a free-plane-wave ? Is there a way to control the wave-function injected in the lead ? Yours sincerely Lorenzo Bagnsacco Il giorno mar 18 gen 2022 alle ore 15:40 Anton Akhmerov < anton.akhmerov...@gmail.com> ha scritto: > 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 >> >>
