Revision of the Decoherence Model: Derivations, Simulations and Protocols

We present a technical revision of an effective decoherence model with explicit fast/slow separation of environmental degrees of freedom. Fast modes are integrated out in the Born–Markov–secular regime, yielding a conditional Lindblad generator whose rates are modulated by a slow variable f(t). Slow modes are coarse-grained into a classical stochastic degree of freedom described by Langevin/Fokker–Planck dynamics. The combined evolution is written as a classical–quantum Fokker–Planck–Lindblad equation preserving complete positivity and trace. We include candidate functional families for the modulation factor with model-form uncertainty, an explicit geometric connection enabling testable predictions, operational inference for the slow-sector variance, full uncertainty propagation, and a concrete experimental protocol for superconducting qubits. v2 (March 11, 2026): Sections IV and V completed (parameter inference and quantitative predictions for superconducting qubits). Section VI added with quantitative comparison against GRW and CSL collapse-style alternatives. Hazard proxy generalized to platform-dependent form. Title updated to reflect current scope.