Hi Adel,
Thanks for the very astute observations! I admit this had me
worried for a little bit, but I'm now confident that I understand
what is going on. While this is not a bug in Kwant, it is
confusing and the tutorial is not showing what it is meant to, so
thank you for pointing this out
I was consulting the example of the current in a closed system and I am a little bit confused:
The figure showing the current flowing inside a circle [1] is obtained for a magnetic field B=0 !
But we know that for B=0, the Hamiltonian is a real symmetric matrix and thus diagonalized by a real orthogonal matrix, so the eigenvectors are real (any phase is just artificial.)
By using the formula giving the current we should find zero !moreover we can ask why we have a current flowing clockwise and not anticlockwise (I remind that B=0) !
When we put B=0.05, we obtain the figures below for the current and the wave function.the wave function has circular symmetry but not the current. Moreover, x and y play exactly the same role so the current should be the same on x and on y (independently from the used gauge)
Am I missing something ?