Dear All, 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 ? Thank you in advance. Adel [1] https://kwant-project.org/doc/1/tutorial/spectrum
