tbkit

tbkit is a Python package to build and solve Tight-Binding models, written in fully vectorized NumPy. It’s built for physics students working through a textbook problem, curious learners exploring a topic on their own, and educators building a demonstration.

Start with the Tutorial, browse the example gallery, or jump straight to the tbkit package API reference.

tbkit is composed of the following classes and modules:

• Lattice

• System

• KSpace

• Plot

• Propagation

• Save

• lattices

• dos

tbkit main features:

• Complex lattice structures.

• Complex-valued onsite energies and hoppings.

• Hermitian and non-Hermitian Tight-Binding Hamiltonians.

• Sublattices.

• Hoppings defined by their type, tags, and angles.

• Any type of hoppings:

  • Neighbors hoppings,

  • Next-neighbors hoppings,

  • Next-next-neighbors hoppings,

  • etc..

• Implementation of onsite energies and hopping patterns:

  • Dimerization defects.

  • Magnetic field (Peierls substitution).

  • Strain.

  • Hopping disorder.

  • Onsite disorder.

• Reciprocal-space Bloch Hamiltonians and band structures.

• Berry curvature and Chern numbers.

• An optional spin-1/2 degree of freedom, for spin-orbit coupling and Zeeman terms.

• Ribbons (edge states) cut from any periodic model.

• Broadened density of states.

• A small library of ready-made lattices.

• Time propagation.

tbkit is available at cpoli/tbkit and on PyPI at https://pypi.org/project/tbkit/

To use tbkit:

• Install Python 3.10 or later and three additional packages:

  • numpy

  • scipy

  • matplotlib

• pip install -e . from a clone of the repository.

Examples are available at cpoli/tbkit, and rendered with their output in the example gallery.