Variational-LSE-Solver

This repo contains the code for the PennyLane-based variational-lse-solver library introduced in "Comprehensive Library of Variational LSE Solvers", N. Meyer et al. (2024).

Setup and Installation

The library requires an installation of python 3.12, and following libraries:

• pennylane~=0.34
• torch~=2.1.2
• tqdm~=4.66.2

We recommend setting up a conda environment:

conda create --name ENV_NAME python=3.12
conda activate ENV_NAME

The package variational-lse-solver can be installed locally via:

pip install variational-lse-solver

Usage and Further Information

For further usage details and examples please refer to the repository https://github.com/nicomeyer96/variational-lse-solver

Acknowledgements

The variational-lse-solver library is mostly based on the techniques introduced in "Variational Quantum Linear Solver", C. Bravo-Prieto et al., Quantum 7, 1188 (2023).

The concept of using dynamically growing circuits is inspired by "Variational quantum linear solver with a dynamic ansatz", H. Patil et al., Phys. Rev. A 105, 012423 (2022)

There are some alternative implementations of subroutines provided by variational-lse-solver in the PennyLane Demos:

• https://pennylane.ai/qml/demos/tutorial_vqls/
• https://pennylane.ai/qml/demos/tutorial_coherent_vqls/

However, those realisations contain several hard-coded parts and can not be used for arbitrary problems out of the box. Furthermore, we identified some small inaccuracies, which might lead to converging to a wrong solution -- this is explained in more detail in the documentation of variational-lse-solver.

Citation

If you use the variational-lse-solver or results from the paper, please cite "Comprehensive Library of Variational LSE Solvers", N. Meyer et al. (2024).

Version History

Initial release (v1.0): April 2024

License

Apache 2.0 License