1.3.rst

What's new in Kwant 1.3

This article explains the user-visible changes in Kwant 1.3.0, released on 19 May 2017. See also the full list of changes up to the most recent bugfix release of the 1.3 series.

Using high-symmetry builders as models

Builders now have a ~kwant.builder.Builder.fill method that fills a builder instance with copies of a template builder. This can be used to "cut out" shapes from high-symmetry models, or to increase the symmetry period of a lead.

Thus Kwant gains the new concept of a "model". Models may be created manually, or with the new function kwant.continuum.discretize (see next paragraph). There is also support for finalizing models and e.g. calculating their band structure (see Finalizing builders with multiple translational symmetries).

Tools for continuum Hamiltonians

The new sub-package ~kwant.continuum is a collection of tools for working with continuum models and for discretizing them into tight-binding models. It aims at providing a handy interface to convert symbolic Hamiltonians into a builder with N-D translational symmetry that can be use to calculate tight-binding band structures or construct systems with different/lower symmetry. For example in just a few lines we can construct a two-band model that exhibits a quantum anomalous spin Hall phase:

From: :jupyter-download:script:`plot_qahe`