Kwant: a software package for quantum transport

TL;DR

Kwant is a Python software package designed for flexible, high-performance quantum transport simulations across various physical systems, providing an intuitive interface aligned with theoretical concepts.

Contribution

It introduces a user-friendly, modular Python toolkit that simplifies the setup and computation of quantum transport problems using tight-binding models.

Findings

Supports calculations of conductance, noise, and scattering matrices

Enables dispersion relations, modes, and Green's functions computations

Offers an extensible framework for diverse tight-binding Hamiltonian analyses

Abstract

Kwant is a Python package for numerical quantum transport calculations. It aims to be an user-friendly, universal, and high-performance toolbox for the simulation of physical systems of any dimensionality and geometry that can be described by a tight-binding model. Kwant has been designed such that the natural concepts of the theory of quantum transport (lattices, symmetries, electrodes, orbital/spin/electron-hole degrees of freedom) are exposed in a simple and transparent way: Defining a new simulation setup is very close to describing the corresponding mathematical model. Kwant offers direct support for calculations of transport properties (conductance, noise, scattering matrix), dispersion relations, modes, wave functions, various Green's functions, and out-of-equilibrium local quantities. Other computations involving tight-binding Hamiltonians can be implemented easily thanks to its extensible and modular nature. Kwant is free software available at http://kwant-project.org/.