QubiCycle

QubiCycle is a qubit reuse algorithm that reduces the number of qubits required by quantum circuits.
It supports different qubit-reuse strategies (gate reordering and eager measurement) and multiple solver backends (SMT and ILP).

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Environment Setup

This repository includes a Conda environment file:

• qubicycle_environmenr.yml

It specifies all required Python packages and versions.

Create and activate the environment with:

conda env create -f qubicycle_environmenr.yml
conda activate <env_name>

Replace <env_name> with the environment name defined inside qubicycle_environmenr.yml.

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Usage

Quick Start

There are two main entry scripts:

• scale_script.py – runs QubiCycle with divide-and-conquer.
• script.py – runs QubiCycle without divide-and-conquer.

Run them as:

python scale_script.py

or

python script.py

Custom Parameters

If you want to customize parameters (e.g., mode, solver, subset size), you can modify the corresponding arguments inside:

• scale_script.py (divide-and-conquer version), or
• script.py (non-divide-and-conquer version).

Arguments

--input Path to the input QASM file.

--output Path to the output QASM file after applying QubiCycle.

--log Path to the log file that records the execution process.

--mode Qubit-reuse mode. Supported values are:

• none – without gate reordering and without eager measurement.
• reorder – with gate reordering only.
• eager – with eager measurement only.
• all – with both gate reordering and eager measurement.

--k Subset size used only in the scaled (divide-and-conquer) version.

--solver Solver for the optimization. Supported values:

• SMT
• ILP

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Reference

If you use QubiCycle in your research or publications, please cite:

Wen-Chen Yu*, Tian-Fu Chen*, Yu-Hsiang Chan, Jie-Hong R. Jiang, Dah-Wei Chiou, and Yao-Wen Chang, “Optimal Qubit Reuse for Quantum Computation with Gate Reordering and Eager Measurement,” in Proceedings of the IEEE International Conference on Quantum Computing and Engineering (QCE), 2025.

(* equal contribution)

@inproceedings{Yu2025QubiCycle,
  author    = {Wen-Chen Yu* and Tian-Fu Chen* and Yu-Hsiang Chan and Jie-Hong R. Jiang and Dah-Wei Chiou and Yao-Wen Chang},
  title     = {Optimal Qubit Reuse for Quantum Computation with Gate Reordering and Eager Measurement},
  booktitle = {IEEE International Conference on Quantum Computing and Engineering (QCE)},
  year      = {2025}
}