I want to calculate conductance between two different leads. This is what I have tried:
1. build an empty center area. This does not work because kwant doesn't know how to attach leads to an empty area.
2. use lead_1.attach_lead(lead_2). Kwant.plot does not correctly plot two leads, so I suppose it doesn't work.
I don't want to build a center area that is the same with one of the leads, because my system is very large and I suppose this will be time-consuming.