OpenQuantumSim

OpenQuantumSim is a Python interface with a Julia backend for open quantum system simulation. It is aimed at researchers who need Lindblad propagation, Monte Carlo wave-function trajectories, Bloch-Redfield weak-coupling dynamics, collective-spin/Dicke models, restartable sweeps, HDF5 outputs, and state diagnostics without leaving the Python scientific stack.

• One import, no glue code. import openquantumsim as oqs gives the full API: spaces, operators, solvers, diagnostics, plotting, and persistence.

• Julia speed, Python ergonomics. Propagation runs in the packaged OpenQuantumSimJL backend; arrays go in, named results come back.

• Validated, not just benchmarked. Analytic limits and QuTiP reference models are checked in CI on Linux and Windows.

Get started with the Quick Start, browse the Example Gallery, or jump straight to the API Reference. The package is currently an alpha: the API is usable, tested, and published on PyPI, but minor interface changes may still occur before a stable 0.1 release. The solver entry points, the Result object, and the HDF5 result schema are stable-in-practice; see the README for the road to 0.1.0.

If you use OpenQuantumSim in your research, please cite the software release — see the repository CITATION.cff.

Getting Started

• Quick Start
  • Backend Setup and Startup Speed
  • Spontaneous Emission
  • Beyond the Basics
  • Development Install
• Example Gallery
  • Deterministic Qubit Decay
  • Driven Qubit
  • Jaynes-Cummings Dynamics
  • Quantum Trajectories
  • Phase-Space Distributions
  • Entanglement and Emission Spectra
  • Parameter Sweep

Reference

• API Reference
  • Hilbert Spaces
  • Operators and States
  • Solvers
  • Correlations
  • Phase Space
  • Plotting
  • Parameter Sweeps
  • System Builders
  • Results
  • Observables
  • Time-Dependent Hamiltonians
• Tutorial Notebooks
  • Qubit Decay in Five Minutes
  • Qubit Decay with mesolve
  • Restartable Parameter Sweeps
  • Wigner and Husimi-Q Functions
  • State Metrics and Solver Diagnostics
  • Dicke Synchronization with a Collective Spin Ensemble
• Result HDF5 Schema
  • Solver Result Files
  • State Observable Groups
  • Solver Statistics
  • Loading Results
  • Parameter Sweep Output
  • Compatibility Notes

Background

• Theory Notes
  • Lindblad Dynamics
  • Monte Carlo Wave Function
  • Bloch-Redfield Equation
  • Quantum Regression Theorem
  • Secular Approximation and Degeneracies
• Validation Gallery
  • Analytic Qubit Decay
  • Jaynes-Cummings Against QuTiP
  • QuTiP Speed Benchmark
• Performance Benchmarks
  • Benchmark Environment
  • Deterministic Solver: OpenQuantumSim vs QuTiP
  • Python Wrapper Profile
  • Backend Startup Profile
  • Local Sysimage Startup
  • Larger Deterministic Spot Checks
  • Monte Carlo Wave Functions: OpenQuantumSim vs QuTiP
  • Monte Carlo Wave Function Scaling
  • Dicke Mutual-Information Batch Runner
  • Sparse Scaling (Hilbert Dimensions 512-2048)
  • Reproducing Results
• Case Studies
  • Template
  • Available Case Studies