Tkwant: a software package for time-dependent quantum transport

TL;DR

Tkwant is a Python software package extending Kwant for simulating time-dependent quantum transport in nanoelectronic devices, handling complex many-body phenomena within the non-equilibrium Keldysh formalism.

Contribution

It introduces a modular, user-friendly Python tool for simulating time-dependent quantum transport phenomena in nanoelectronics, expanding Kwant's capabilities to include dynamic perturbations.

Findings

Demonstrates applications in plasmon propagation and Majorana spectroscopy

Enables simulation of Floquet topological insulators and thermoelectric effects

Provides an accessible, open-source tool for complex quantum transport simulations

Abstract

Tkwant is a Python package for the simulation of quantum nanoelectronics devices to which external time-dependent perturbations are applied. Tkwant is an extension of the Kwant package (https://kwant-project.org/) and can handle the same types of systems: discrete tight-binding-like models that consist of an arbitrary central region connected to semi-infinite electrodes. The problem is genuinely many-body even in the absence of interactions and is treated within the non-equilibrium Keldysh formalism. Examples of Tkwant applications include the propagation of plasmons generated by voltage pulses, propagation of excitations in the quantum Hall regime, spectroscopy of Majorana fermions in semiconducting nanowires, current-induced skyrmion motion in spintronic devices, multiple Andreev reflection, Floquet topological insulators, thermoelectric effects, and more. The code has been designed to be easy to use and modular. Tkwant is free software distributed under a BSD license and can be found at https://tkwant.kwant-project.org/.