A Python/PyQt6 reimplementation of QCS 2.0, a MATLAB-based quantum circuit simulator originally developed by Dr. Ioannis G. Karafyllidis at the Democritus University of Thrace (DUTh).
This project is a clean-room rewrite in Python. All scientific concepts, gate definitions, simulation logic, and the circuit model are the intellectual work of Dr. Karafyllidis. This repository makes no claim of original scientific contribution.
Author: Dr. Ioannis G. Karafyllidis, Dept. of Electrical & Computer Engineering, Democritus University of Thrace, Greece
Original tool: QCS 2.0 (MATLAB) — available from the author's institutional page
Reference publication:
I. G. Karafyllidis, "Quantum Computer Simulator Based on the Circuit Model of Quantum Computation," IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 52, no. 8, pp. 1590–1596, Aug. 2005. DOI: 10.1109/TCSI.2005.851999
- Python 3.10+ rewrite of the same simulator
- GUI built with PyQt6 (replacing the original MATLAB GUI)
- Plots rendered with matplotlib
- Identical gate set, qubit limits (≤ 6), and step limits (≤ 12)
- Compatible with original QCS circuit files (
QuantGate.txt,QuantPhase.txt,QuantReg.txt,QuantLinstp.txt)
| Code | Gate | Description |
|---|---|---|
| 0 | I | Identity |
| 1 | H | Hadamard |
| 2 | PHG | Phase gate |
| 3 | CN | CNOT target |
| 4 | CCX | Toffoli target |
| 5 | F | Fredkin gate |
| 6 | CPH | Controlled phase gate |
| 8 | F· | Fredkin cover |
| 9 | ctrl | Control qubit marker |
| 10 | X | Pauli X |
| 11 | Y | Pauli Y |
| 12 | Z | Pauli Z |
| 13 | M | Partial measurement |
numpy>=1.26.0
PyQt6>=6.6.0
matplotlib>=3.8.0
Install:
pip install -r requirements.txt
python qcs.py- Click any cell in the circuit grid to assign a gate
- Set qubit initial states by clicking the toggle buttons (|0⟩ / |1⟩)
- Press Run Simulation to compute and plot results
- Use Load / Save to work with circuit files
This repository contains no code derived from the original MATLAB implementation. The Python code is released under the MIT License. The underlying scientific work remains the property of its original author — please cite the paper above if you use this tool in academic work.