Your browser has javascript turned off or blocked. This will lead to some parts of our website to not work properly or at all. Turn on javascript for best performance.

The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Portrait of Martin Leijnse; Photo: Kennet Ruona

Martin Leijnse

Professor, Member of NanoLund Management Group

Portrait of Martin Leijnse; Photo: Kennet Ruona

QmeQ 1.0 : An open-source Python package for calculations of transport through quantum dot devices

Author

  • Gediminas Kirsanskas
  • Jonas Nyvold Pedersen
  • Olov Karlström
  • Martin Leijnse
  • Andreas Wacker

Summary, in English

QmeQ is an open-source Python package for numerical modeling of transport through quantum dot devices with strong electron-electron interactions using various approximate master equation approaches. The package provides a framework for calculating stationary particle or energy currents driven by differences in chemical potentials or temperatures between the leads which are tunnel coupled to the quantum dots. The electronic structures of the quantum dots are described by their single-particle states and the Coulomb matrix elements between the states. When transport is treated perturbatively to lowest order in the tunneling couplings, the possible approaches are Pauli (classical), first-order Redfield, and first-order von Neumann master equations, and a particular form of the Lindblad equation. When all processes involving two-particle excitations in the leads are of interest, the second-order von Neumann approach can be applied. All these approaches are implemented in QmeQ. We here give an overview of the basic structure of the package, give examples of transport calculations, and outline the range of applicability of the different approximate approaches. Program summary: Program Title: QmeQ Program Files doi: http://dx.doi.org/10.17632/8687mrhgg9.1 Licensing provisions: BSD 2-Clause. Programming language: Python External libraries: NumPy, SciPy, Cython Nature of problem: Calculation of stationary state currents through quantum dots tunnel coupled to leads. Solution method: Exact diagonalization of the quantum dot Hamiltonian for a given set of single particle states and Coulomb matrix elements. Numerical solution of the stationary-state master equation for a given approximate approach. Restrictions: Depending on the approximate approach the temperature needs to be sufficiently large compared to the coupling strength for the approach to be valid.

Department/s

  • Mathematical Physics
  • NanoLund: Center for Nanoscience
  • Solid State Physics

Publishing year

2017-08-19

Language

English

Pages

317-342

Publication/Series

Computer Physics Communications

Volume

221

Document type

Journal article

Publisher

Elsevier

Topic

  • Other Physics Topics
  • Software Engineering

Keywords

  • Anderson-type model
  • Coulomb blockade
  • Open quantum systems
  • Python
  • Quantum dots

Status

Published

ISBN/ISSN/Other

  • ISSN: 0010-4655