Papers
qcr:2606.96335.1

How to Write a Simulator for Quantum Circuits from Scratch: A Tutorial

arXiv

Michael J. McGuffin, Jean-Marc Robert, Kazuki Ikeda

This tutorial guides a competent programmer through the crafting of a quantum circuit simulator from scratch, even for readers with almost no prior experience in quantum computing. Open source simulators for quantum circuits already exist, but a deeper understanding is gained by writing ones own. With roughly 1000-2000 lines of code, one can simulate Hadamard, Pauli X, Y, Z, SWAP, and other quantum logic gates, with arbitrary combinations of control and anticontrol qubits, on circuits of up to 20+ qubits, with no special libraries, on a personal computer. We explain key algorithms for a simulator, in particular: qubit-wise multiplication for updating the state vector, and partial trace for finding a reduced density matrix. We also discuss optimizations, and how to compute qubit phase, purity, and other statistics. A complete example implementation in JavaScript is available at https://github.com/MJMcGuffin/muqcs.js , which also demonstrates how to compute von Neumann entropy, concurrence (to quantify entanglement), and magic, while remaining much smaller and easier to study than other popular software packages.
10.48550/arxiv.2506.08142
Published 2025
Uploaded 1 day ago
21
Views
View Publication
Citing this entry? Use this QCR ID
Uploaded by
QL
QCR Librarian

Overview

Join the Discussion

Comments (0)

No comments yet. Be the first to share your thoughts!

Indexed by QCR Librarian

This entry was created automatically from publicly available records. QCR links to public sources and only stores repository content where the license permits redistribution.

Related Code1

Related Tutorials0

No tutorials cover this paper yet. Add a tutorial →

Versions

v1 Latest
Jun 17, 2026
qcr:2606.96335.1

Cite all versions? Use the base QCR ID to always reference the latest version of this entry.