Contents

Introduction¶

Welcome to fast-pauli from Qognitive, an open-source Python / C++ library for optimized operations on Pauli matrices and Pauli strings, inspired by PauliComposer paper. fast-pauli aims to provide a fast and efficient alternative to existing libraries for working with Pauli matrices and strings, with a focus on performance and usability. For example, fast-pauli provides optimized functions to apply Pauli strings and operators to a batch of states rather than just a single state vector. See our Getting Started guide for an introduction to some of the core functionality in fast-pauli and our Benchmarks for more details about how fast-pauli can speed up certain functions compared to Qiskit.

Installation¶

In order to get started, we’ll need to install the package and its dependencies.

Requirements¶

CMake >= 3.25
Ninja >= 1.11
C++ compiler with OpenMP and C++20 support (LLVM recommended)
Python >= 3.10
scikit-build-core (ONLY for building from source with custom configuration)

In the following subsections, we describe several options for installing fast_pauli.

Install the Latest Release¶

pip install fast_pauli

Build from Source (Linux)¶

git clone [email protected]:qognitive/fast-pauli.git
cd fast_pauli
python -m pip install -e ".[dev]"

Build from Source (MacOS)¶

git clone [email protected]:qognitive/fast-pauli.git
cd fast_pauli
python -m pip install --upgrade pip
python -m pip install scikit-build-core
brew install llvm
pip install -e . -C cmake.args="-DCMAKE_CXX_COMPILER=$(brew --prefix llvm)/bin/clang++;-DCMAKE_CXX_FLAGS='-stdlib=libc++ -fexperimental-library'"

Build from Source (Custom Config)¶

git clone [email protected]:qognitive/fast-pauli.git
cd fast-pauli
python -m pip install --upgrade pip
python -m pip install scikit-build-core
python -m pip install --no-build-isolation -ve ".[dev]" -C cmake.args="-DCMAKE_CXX_COMPILER=<compiler> + <other cmake flags>"

Verify / Test Build¶

pytest -v tests/fast_pauli # + other pytest flags