qlbm documentation

The long-term goal of qlbm is to be a quantum computational fluid dynamics (QCFD) solver for fault-tolerant quantum computers running on a heterogeneous quantum-classical high-performance computer (QHPC). Currently, the primary aim of qlbm is to accelerate and improve the research surrounding Quantum Lattice Boltzmann Methods (QLBMs). On this website, you can find the Internal Documentation of the source code components that make up qlbm. A paper describing qlbm in detail is available on here [2].

qlbm is made up of 4 main modules. Together, the Base Classes, Collisionless Circuits, Space-Time Circuits, and LQLGA Circuits modules handle the parameterized creation of quantum circuits that compose QBMs. The Lattices and Geometry module parses external information into quantum registers and provides uniform interfaces for underlying algorithms. The Infrastructure module integrates the quantum components with Tket, Qiskit, and Qulacs transpilers and runners. The Other Tools module contains miscellaneous utilities.

qlbm currently supports three algorithms:

1. The Collisionless QLBM (CQLBM) first described in [5] and later expanded in [6].

2. Space-Time QLBM (STQLBM) described in [7] and [1].

3. Linear Quantum Lattice Gas Automata (LQLGA) described in [1], [4], and [3].

Internal Documentation

Detailed documentation of qlbm.

Internal Documentation

Tutorials

Hands-on examples.

Tutorials

Code documentation

• Internal Documentation
  • Base Classes
  • Collisionless Circuits
  • Collision Logic Classes
  • Space-Time Circuits
  • LQLGA Circuits
  • Lattices and Geometry
  • Infrastructure
  • Other Tools
• Tutorials
  • Visualizing Collisionless QLBM circuits
  • Visualizing Space-Time circuits
  • Visualizing LQLGA circuits
  • Visualizing Geometry
  • Flowfield Visualization

References

[1] (1,2)

Călin A Georgescu, Merel A Schalkers, and Matthias Möller. Fully quantum lattice gas automata building blocks for computational basis state encodings. arXiv preprint arXiv:2506.12662, 2025.

[2]

Călin A. Georgescu, Merel A. Schalkers, and Matthias Möller. Qlbm – a quantum lattice boltzmann software framework. Computer Physics Communications, 315:109699, 2025. URL: https://www.sciencedirect.com/science/article/pii/S0010465525002012, doi:https://doi.org/10.1016/j.cpc.2025.109699.

[3]

Sriharsha Kocherla, Zhixin Song, Fatima Ezahra Chrit, Bryan Gard, Eugene F Dumitrescu, Alexander Alexeev, and Spencer H Bryngelson. Fully quantum algorithm for mesoscale fluid simulations with application to partial differential equations. AVS Quantum Science, 2024.

[4]

Peter Love. On quantum extensions of hydrodynamic lattice gas automata. Condensed Matter, 4(2):48, 2019.

[5]

Merel A. Schalkers and Matthias Möller. Efficient and fail-safe quantum algorithm for the transport equation. Journal of Computational Physics, 502:112816, 2024.

[6]

Merel A. Schalkers and Matthias Möller. Momentum exchange method for quantum boltzmann methods. Computers & Fluids, 285:106453, 2024.

[7]

Merel A. Schalkers and Matthias Möller. On the importance of data encoding in quantum boltzmann methods. Quantum Information Processing, 23(1):20, 2024.