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.

I'm afraid that the way Kwant works at the moment means that you will need to build a
central system if you want to calculate transport properties! On some level this makes
sense, as you need to define how the two leads are coupled.

If this is really inhibiting your ability to actually solve problems, then the only
short-term solution would be to use Kwant to calculate the modes in the leads
and then set up the scattering problem manually. This would probably be
exponentially more work for *you*, however. How wide are your leads that
this is really a problem? Did you benchmark the runtime?

Happy Kwanting,