Stability analysis with quantum reservoir computers and robust design with generalized synchronization

This repository provides a framework for studying the stability of chaotic dynamical systems using Quantum Reservoir Computing (QRC) and Recurrence-free Quantum reservoir computing (RF-QRC). We also use Generalised Synchronisation (GS) theory to design robust quantum reservoir computers. It includes tools for computing invariant properties such as Lyapunov exponents, Covariant Lyapunov Vectors (CLVs) and Conditional Lyapunov Exponents (CLEs) via a Qiskit-based implementation.

Repository Structure

• src/Notebook.ipynb
  Contains the main workflow to evaluate stability properties with quantum reservoir computers. Input data can be modified to extend the framework to other systems such as Lorenz96 for which the solvers are already added. Quantum noise models and the number of measurement shots can also be varied.

• src/QRC/qrc.py
  Implements the Qiskit-based quantum reservoir and the methods required to compute Lyapunov exponents, including both conditional and autonomous versions, using quantum circuit simulations.

Usage

To get started: First, install the required dependencies:

pip install -r requirements.txt

Then run the following notebook

python Notebook.ipynb

Citation

If you use this code in your research, please cite the corresponding paper:

Robust quantum reservoir computers for forecasting chaotic dynamics: generalized synchronization and stability (https://arxiv.org/abs/2506.22335)