Note
This repository is under active development and the code here should not be considered stable.
Qiskit swapnet is a package for laying out and routing a single QAOA cost layer onto a real device within a budget of k parallel SWAP layers. It enables the creation of practical-depth QAOA layers by solving an approximated problem rather than the full original one. Specifically, it contains:
- Problem definitions from a covariance matrix, a QUBO, or a general coupling matrix, together with the coupling weights that the layout and routing stages expect.
- Analytic rank-0 and rank-1 shifts, which implement the dominant part of the couplings in a single layer of RZ rotations, with no two-qubit gates and no routing.
- Qubit layout by quadratic assignment, and SWAP routing by prize-collecting vertex-disjoint multi-commodity flow.
- Hardware descriptions built from a backend, with per-link traversal costs derived from device error rates.
- Construction of the resulting cost-layer circuit from an algorithm-neutral
Schedule, so swapnet can be replaced by another routing algorithm without changing anything downstream.
All documentation will be available on IBM Quantum Platform soon.
swapnet includes a native C++ extension, so building it requires a C++ compiler and CMake. Install it from source:
git clone git@github.com:Qiskit/qiskit-swapnet.git
cd qiskit-swapnet
pip install -e '.[dev]'The core is Qiskit-free. To install only the core, without Qiskit and the fake backends, use pip install -e '.[highs,graphs]'.
For more installation information refer to these installation instructions.
The source code is available on GitHub.
The developer guide is located at CONTRIBUTING.md in the root of this project's repository. By participating, you are expected to uphold Qiskit's code of conduct.
If you use this package in your research, use the CITATION.bib file in this project’s repository to cite the appropriate reference(s).
We follow semantic versioning. We may occasionally make breaking changes in order to improve the user experience. When possible, we will keep old interfaces and mark them as deprecated, as long as they can co-exist with the new ones. Each substantial improvement, breaking change, or deprecation will be documented in the release notes.