QuantumFCS.jl

QuantumFCS.jl computes the Full Counting Statistics (FCS) of open quantum systems — current cumulants to arbitrary order for Lindblad master equations — using a recursive scheme built on the Drazin inverse of the Liouvillian. Currents are specified by choosing monitored jump operators (mJ) and their weights (nu), so the same Liouvillian can be reused for particle, photon, charge, or heat currents.

The package works with plain arrays, QuantumOptics.jl, and QuantumToolbox.jl. It ships two Drazin backends (direct LU and a matrix-free iterative solver), plus prepared contexts for reusing solver setup across several observables.

• ⚡ Start with the Quickstart
• 📘 Read up on the Mathematical Background
• ⚙️ Pick a backend for large systems in Drazin solvers
• 📝 Study the Examples, including two applications from the companion paper: the driven-dissipative Jaynes–Cummings model and a circuit-QED heat engine
• 🧭 Browse the API