Hi,

We consider the values of the  conservation law based on the off-diagonal term of Hamiltonian matrix, details are as follows:

H = tinyarray.array([[0, 0, 0, 1, 0, 0],

[0, 0, 0, 0, 1, 0],

[0, 0, 0, 0, 0, 1],

[1, 0, 0, 0, 0, 0],

[0, 1, 0, 0, 0, 0],

[0, 0, 1, 0, 0, 0]])

I don't really understand; is this the full Hamiltonian?

spin_block = tinyarray.array([[0, 0, 0, 1, 0, 0],

[0, 0, 0, 0, 1, 0],

[0, 0, 0, 0, 0, 1],

[-1, 0, 0, 0, 0, 0],

[0, -1, 0, 0, 0, 0],

[0, 0, -1, 0, 0, 0]])

And we add “conservation_law= - spin_block” in  “lead=kwant.Builder()”

The program can not work, and prompt error:

IndexError: index 2 is out of bounds for axis 0 with size 2

There is not enough information for me to be able to help you. Please attach a complete Kwant script.

Happy Kwanting,

Joe