Active Broadcast Versus Passive Decoherence in Redundant Record Formation

Quantum Darwinism explains the emergence of classical objectivity through redundant environmental encoding of quantum information. Many treatments implicitly treat redundancy as mechanism-agnostic — that is, redundancy is redundancy regardless of how it arises. In this work, I distinguish two channel classes through which environmental records form: passive decoherence, in which information leaks into unstructured environmental degrees of freedom, and active broadcast, in which classical records propagate via selective, high-fan-out channels. I show computationally that these classes produce measurably different redundancy growth rates and record-stability thresholds under comparable noise conditions, and that the distinction is not an artefact of parameter choice but reflects a difference in scaling class: passive (local) channels produce scaling consistent with polynomial spreading times T(N) ~ Nᵝ, while active (non-local) channels produce scaling consistent with logarithmic spreading times T(N) ~ log(N), under the models studied. This separation is consistent with locality constraints formalised by Lieb–Robinson bounds on information propagation in locally-coupled systems. The distinction implies that the route to classicality is not uniquely determined by the quantity of redundancy, but depends on the informational structure of the channel that generates it. This has direct consequences for how we understand irreversibility, the objectivity of measurement outcomes, and the scope of quantum Darwinism as a theory of the classical limit.