WaveguideQED.jl - Modeling Propagating Photons in Julia

Learn to model propagating photons in quantum systems using WaveguideQED.jl, a high-performance Julia package presented at JuliaCon Global 2025. Discover how this framework leverages Julia's multiple dispatch and lazy evaluation to efficiently handle time-dependent quantum mechanical operators, moving beyond traditional sparse matrix methods to employ matrix-free operator applications through non-allocating kernel functions. Explore the package's ability to simulate up to two propagating photons while studying non-Markovian feedback and multiphoton entanglement phenomena. Understand how WaveguideQED.jl integrates seamlessly with QuantumOptics.jl and provides a flexible interface familiar to users of quantum optics toolkits like QuTiP, Quantum Toolbox, and QuantumToolbox.jl. Examine practical demonstrations including photon scattering calculations, quantum feedback simulations, and multi-photon dynamics in waveguides. See how lazy operator application significantly reduces memory overhead and computational complexity through detailed benchmarks. Gain insights into the framework's modular design that enables construction of arbitrary local quantum systems for studying complex quantum optical interactions, with future developments focusing on Monte Carlo trajectory methods for exploring system losses and expanding the maximum number of propagating photons.