Qiskit BIPMapping Plugin

This repository contains a standalone routing stage to use the BIPMapping routing pass. The BIP mapping pass solves the routing and layout problems as a binary integer programming (BIP) problem. The algorithm used in this pass is described in:

G. Nannicini et al. "Optimal qubit assignment and routing via integer programming." arXiv:2106.06446

This plugin depends on CPLEX to solve the BIP problem. While a no-cost version of CPLEX is available (and published on PyPI) this has limits set on the size of the problems it can solve which prevents it from being used except for very small quantum circuits. If you would like to use this transpiler pass for larger circuits a CPLEX license will be required.

Install and Use plugin

To use the unitary synthesis plugin first install qiskit terra with the pull request:

pip install qiskit-bip-mapper

To install the plugin package. As part of the install process pip will install the no-cost version of CPLEX from PyPI automatically. However, if you're going to use the qiskit-bip-mapper plugin for running transpile() on circuits more than a couple qubits or with more than handful of 2 qubit gates you will likely need to install the commercial version of CPLEX.

Using BIPMapping pass

Once you have the plugin package installed you can use the plugin via the routing_method="bip" argument on Qiskit's transpile() function. For example, if you wanted to use the BIPMapping method to compile a 15 qubit quantum volume circuit for a backend you would do something like:

from qiskit import transpile
from qiskit.circuit.library import QuantumVolume
from qiskit.providers.fake_provider import FakePrague

qc = QuantumVolume(15)
qc.measure_all()
backend = FakePrague()

transpile(qc, backend, routing_method="bip")

Authors and Citation

The qiskit-bip-mapper is the work of many people who contribute to the project at different levels. Additionally, the plugin was originally developed as part of the Qiskit project itself and you can see the development history for it here:

• https://github.com/Qiskit/qiskit-terra/commits/0.23.3/qiskit/transpiler/passes/routing/bip_mapping.py
• https://github.com/Qiskit/qiskit-terra/commits/0.23.3/qiskit/transpiler/passes/routing/algorithms/bip_model.py

If you use qiskit-bip-mapper in your research, please cite our paper as per the included BibTeX file file.