qex 0.1.2

A lightweight experiment-runner and lab notebook for quantum computing

qex

A lightweight experiment-runner and lab notebook for quantum computing, built on top of Cirq.

Overview

qex is designed for running quantum experiments, tracking results, and visualizing outcomes. It focuses on reproducibility, persistence, and visualization rather than being a general-purpose quantum framework.

Key Features:

• 🧪 Experiment Management: Define parametric quantum circuits and run them systematically
• 💾 Result Persistence: Store runs, results, and metadata in SQLite
• 📊 Visualization: Automatic Bloch sphere visualization for 1-qubit states
• 🔬 Reproducibility: All parameters and results are stored for later analysis
• 🚀 Simple API: Minimal, opinionated design focused on experiments

Installation

pip install qex

Quick Start

from qex import CirqBackend, Runner, ResultStore
from qex.demos import hadamard_experiment
from pathlib import Path

# Setup
backend = CirqBackend()
runner = Runner(backend)
store = ResultStore(Path("qex_data/qex.db"))

# Run an experiment
experiment = hadamard_experiment()
record = runner.run(experiment, params={})

# Persist results
store.save_run(record)

# Retrieve and view
runs = store.list_runs(experiment_name="hadamard")
rho = runs[0].get_density_matrix()
print(f"Density matrix:\n{rho}")

store.close()

Built-in Experiments

qex includes three demo experiments for validation:

• X Gate: |0⟩ → X → |1⟩ - Simple bit flip
• Hadamard: |0⟩ → H → superposition - Creates equal superposition
• Ry Sweep: |0⟩ → Ry(θ) - Rotation around Y-axis with parameter theta

Documentation

• API Reference: Complete API documentation
• Design Specification: Architecture and design decisions
• Database Schema: SQLite schema documentation
• Bloch Sphere Contract: Visualization math and interface

Current Scope (MVP)

• ✅ 1-qubit experiments only
• ✅ Ideal simulation (no noise)
• ✅ Density matrix results
• ✅ SQLite persistence
• ✅ Bloch sphere HTML visualization
• ✅ Cirq-based backend

Requirements

• Python >= 3.12
• Cirq >= 1.6.1
• NumPy >= 1.24.0

License

Apache License 2.0

Contributing

Contributions are welcome! Please see the Design Specification for architecture details and constraints.