I messaged a coupled months back on a basic question. I have another one. KWANT has been very useful to me so far, and I like to think I've made some progress with it, however, I still occasionally am tripping up on basic things. I'm sorry if the answer to this is obvious.

I am trying to create an SNS junction to study helical ABSs in a magnetic field, but I'm having some basic problems implementing the magnetic field in the code along with the Bogliubov de-Gennes equation. Using the tutorials and paper as my guide, I'm defining a global method for the hopping and have tried to use it in the system, without success. How would I implement it with the hoppings with the superconductor formalism, with separate leads for electrons and holes? Is there something I'm missing on how to do it-you can't just use the magentic field as the hopping, as in the examples. Would I just subtract it as a gauge from the Hamiltonian diagonal entries, as you do analytically?  Is there an example out there for that?

At the moment, as a side question, when I try to simply to multiply the magnetic field with 4t-mu, I'm getting a ValueError: that the hoppings then do not match the dimensions of the onsite Hamiltonian. So I'm guessing that's not the way of going about it. 

Thank you.