MQT Core - The Backbone of the Munich Quantum Toolkit (MQT)

MQT Core is an open-source C++20 and Python library for quantum computing that forms the backbone of the quantum software tools developed as part of the Munich Quantum Toolkit (MQT).

Key Features

• Fully fledged intermediate representation (IR) for quantum computations.
• A state-of-the-art decision diagram (DD) package for quantum computing.
• A dedicated ZX-diagram package for working with the ZX-calculus.

If you have any questions, feel free to create a discussion or an issue on GitHub.

Contributors and Supporters

The Munich Quantum Toolkit (MQT) is developed by the Chair for Design Automation at the Technical University of Munich and supported by the Munich Quantum Software Company (MQSC). Among others, it is part of the Munich Quantum Software Stack (MQSS) ecosystem, which is being developed as part of the Munich Quantum Valley (MQV) initiative.

Thank you to all the contributors who have helped make MQT Core a reality!

The MQT will remain free, open-source, and permissively licensed—now and in the future. We are firmly committed to keeping it open and actively maintained for the quantum computing community.

To support this endeavor, please consider:

• Starring and sharing our repositories: https://github.com/munich-quantum-toolkit
• Contributing code, documentation, tests, or examples via issues and pull requests
• Citing the MQT in your publications (see Cite This)
• Citing our research in your publications (see References)
• Using the MQT in research and teaching, and sharing feedback and use cases
• Sponsoring us on GitHub: https://github.com/sponsors/munich-quantum-toolkit

Getting Started

mqt.core is available via PyPI for all major operating systems and supports Python 3.9 to 3.14.

(.venv) $ pip install mqt.core

The following code gives an example on the usage:

from mqt.core import QuantumComputation

qc = QuantumComputation(2, 2)
qc.h(0)
qc.cx(0, 1)
qc.measure(range(2), range(2))

print(qc)

Detailed documentation and examples are available at ReadTheDocs.

System Requirements

Building (and running) is continuously tested under Linux, MacOS, and Windows using the latest available system versions for GitHub Actions. However, the implementation should be compatible with any current C++ compiler supporting C++20 and a minimum CMake version of 3.24.

MQT Core relies on some external dependencies:

• nlohmann/json: A JSON library for modern C++.
• boost/multiprecision: A library for multiprecision arithmetic (used in the ZX package).
• google/googletest: A testing framework for C++ (only used in tests).
• pybind/pybind11_json: Using nlohmann::json with pybind11 (only used for creating the Python bindings).

CMake will automatically look for installed versions of these libraries. If it does not find them, they will be fetched automatically at configure time via the FetchContent module (check out the documentation for more information on how to customize this behavior).

It is recommended (although not required) to have GraphViz installed for visualization purposes.

If you want to use the ZX library, it is recommended (although not strictly necessary) to have GMP installed in your system.

Cite This

Please cite the work that best fits your use case. If both apply, include both references.

MQT Core (the tool)

When citing the software itself or results produced with it, cite the MQT Core paper:

@article{burgholzer2025MQTCore,
    title        = {{{MQT Core}}: {{The}} Backbone of the {{Munich Quantum Toolkit (MQT)}}},
    author       = {Lukas Burgholzer and Yannick Stade and Tom Peham and Robert Wille},
    year         = 2025,
    journal      = {Journal of Open Source Software},
    publisher    = {The Open Journal},
    volume       = 10,
    number       = 108,
    pages        = 7478,
    doi          = {10.21105/joss.07478},
    url          = {https://doi.org/10.21105/joss.07478},
}

The Munich Quantum Toolkit (the project)

When discussing the overall MQT project or its ecosystem, cite the MQT Handbook:

@inproceedings{mqt,
    title        = {The {{MQT}} Handbook: {{A}} Summary of Design Automation Tools and Software for Quantum Computing},
    shorttitle   = {{The MQT Handbook}},
    author       = {Robert Wille and Lucas Berent and Tobias Forster and Jagatheesan Kunasaikaran and Kevin Mato and Tom Peham and Nils Quetschlich and Damian Rovara and Aaron Sander and Ludwig Schmid and Daniel Schoenberger and Yannick Stade and Lukas Burgholzer},
    booktitle    = {IEEE International Conference on Quantum Software (QSW)},
    doi          = {10.1109/QSW62656.2024.00013},
    year         = 2024,
    eprint       = {2405.17543},
    eprinttype   = {arxiv},
    addendum     = {A live version of this document is available at \url{https://mqt.readthedocs.io}},
}

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Acknowledgements

The Munich Quantum Toolkit has been supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 101001318), the Bavarian State Ministry for Science and Arts through the Distinguished Professorship Program, as well as the Munich Quantum Valley, which is supported by the Bavarian state government with funds from the Hightech Agenda Bayern Plus.