clerq

clerq solves the propagation of classical electromagnetic fields through media of open quantum systems, using Maxwell's equations coupled to the Lindblad master equation. It is used for near-resonant light in thermal atomic vapours, with two-, three- and many-level atoms, spontaneous decay, dephasing and Doppler broadening.

Renamed from maxwellbloch. This package was previously published as maxwellbloch. Install clerq and change import maxwellbloch to import clerq. The old name keeps working through a transitional release that re-exports clerq with a DeprecationWarning. Version 0.13.0 also fixes a factor-of-2 error in the propagation equation, so results from earlier versions change. See the announcement.

Above is an example solution for the propagation of a 4π pulse through a dense atomic vapour. The pulse immediately breaks up on entering the medium and the resultant pulses form two optical solitons each with a pulse area of 2π.

Documentation

Docs for the project are at clerq.org.

Install

The recommended way to install is via uv:

uv pip install clerq

Or using pip:

pip install clerq

If you prefer Conda, you can create and activate an environment with the required dependencies with

conda create --name mb -c conda-forge python=3.11 qutip
conda activate mb
pip install clerq

More detailed installation instructions can be found in the docs along with many example problems.

Attribution

If you use clerq for research, please cite the original package, which was published as MaxwellBloch:

@misc{ogden2020maxwellbloch,
  author = {Ogden, Thomas P.},
  title = {{MaxwellBloch}: a Python package for solving the coupled 
    Maxwell-Bloch equations describing the nonlinear propagation of 
    near-resonant light through thermal quantised systems such as atomic 
    vapors.},
  year = {2020},
  publisher = {GitHub},
  journal = {GitHub repository},
  howpublished = {\url{https://github.com/tpogden/clerq}}
}

A CITATION.cff for clerq is included (GitHub's "Cite this repository" button reads it). A citation with its own DOI will be added once the first archived release under the new name is available.

Changelog

See CHANGELOG.md.

License

MIT License. See LICENSE.txt.