Modernize the low-level system format
The new low-level systems should support
- Multiple directions of translational symmetry
- Other spatial symmetries
- Vectorization of evaluation
- Parameters to the Hamiltonian
In addition, "introspection" should work better than now. I.e. it should be much easier to
- Work with "density" observables
- Evaluate useful sub-terms of the Hamiltonian (e.g. slices of the graph, or the part that depends on a particular parameter)
We can add the new low-level systems to Kwant 1 as kwant.system.System2
(or similar), so as to keep backwards-compatibility.
Edited by Christoph Groth