Quantikz Tutorial - A Quantum Circuit Typesetting Tool for LaTeX

Welcome to the Quantikz tutorial repository, designed to help you create elegant quantum circuit diagrams with LaTeX and the Quantikz package. This guide offers installation instructions, usage examples, and detailed explanations of Quantikz's features.

Quantikz is a TikZ-based library that provides a more intuitive and customizable alternative to QCircuit for typesetting quantum circuits in LaTeX.

This tutorial summarizes Alastair Kay's paper, "Tutorial on the Quantikz Package," and includes examples and tips for effective use of the package.

Overview

Quantikz is a TikZ library designed for typesetting quantum circuits. It allows users to create diagrams in a matrix-like structure, enabling easy manipulation of quantum and classical wires, gates, and measurements.

Introduction

Quantikz is a LaTeX package built on top of TikZ, designed specifically for typesetting quantum circuits. It serves as a modern alternative to QCircuit, with a simpler and more intuitive syntax. Whether you're new to quantum computing or a seasoned researcher, Quantikz allows you to create professional, publication-quality quantum circuits with ease.

Key Advantages:

• Quantum and Classical Wires: Support for quantum, classical, and bundled wires.
• Customizable Gates: Create a wide variety of gates, including single-qubit gates, multi-qubit gates, and controlled gates.
• Highlighting and Slicing: Easily highlight parts of your circuit and slice it for step-by-step explanations.
• Backward Compatibility: Quantikz offers features to convert from QCircuit and remains backward-compatible with older versions.

Table of Contents

1. Installation
2. Basic Usage
   • Quantum Wires
   • Gates and Measurement
   • Controlled Gates
   • Labelling Circuits
3. Exporting Diagrams
4. Commands and Options
5. Converting from QCircuit
6. Troubleshooting
7. Citation
8. License

Installation

To use Quantikz, ensure that your LaTeX distribution includes the Quantikz package. Most current TeX distributions should have it available. In your LaTeX document, include the following in the preamble:

\usepackage{tikz}
\usetikzlibrary{quantikz2}

If you're uploading to arXiv, you may need to manually include the Quantikz file by adding tikzlibraryquantikz2.code.tex to your project.

Basic Usage Quantum Wires In Quantikz, quantum circuits are organized in a matrix-like format. Each column is separated by &, and new rows are created with \. By default, all wires are quantum wires.

\begin{quantikz}
& \gate{H} & \ctrl{1} & \gate{X} & \meter{} \\
& \targ{}  & \ctrl{-1} & \gate{H} & \meter{}
\end{quantikz}

This creates a basic quantum circuit with Hadamard (H), controlled gate (ctrl), Pauli-X (X), and measurement gates.

Gates and Measurement Use the \gate command to add gates. You can also add measurement gates (\meter) and phase gates (\phase):

\begin{quantikz}
& \gate{H} & \gate[2]{U} & \gate{R_Z(\theta)} & \meter{} \\
& & & \phase{\alpha} &
\end{quantikz}
Controlled Gates
For controlled gates, use the \ctrl and \targ commands. Here's an example of a controlled gate and a swap gate:

\begin{quantikz}
& \ctrl{1} & \targ{} & \swap{1} & \ctrl[vertical wire=c]{2} & \\
& \control{} & \ctrl[open]{-1} & \targX{} & \gate{X} & \\
&&&& \gate{U} & \meter{} \wire[u][1]{c}
\end{quantikz}