hello
looking what is happening here
fidelity(k) = abs(bra_nplus1 * psi_ket_out_norm).^2;
I found out that bra_nplus1 and psi_ket_out_norm vectors will always have only one non zero value at the same index position. the value at this index is either 1 or -1 so the product of the two vectors , once abs is applied , will always be one.
Only the position of the +1 / - 1 value inside those vectors vary with the loop index but the product will always give the same result (1)
