Procrastinating einselection in non-Markovian quantum dynamics

Abstract

Among the processes governed by open-system and dissipative quantum dynamics, environment-induced superselection, or einselection, is particularly foundational, since it describes the formation of a preferred set of pointer states through environmental monitoring and ultimately the emergence of classicality. Especially in the context of Quantum Darwinism, einselection can be studied in terms of the motion of an observable towards its pointer value. To this end, we derive a quantum speed limit for observables for finite-dimensional systems governed by differentiable time-local open dynamics. We identify two mechanisms through which non-Markovianity can enhance observable speed: direct dissipative motion supported by population retention or revival, and indirect enhancement through restoration of the asymmetry available for coherent motion. For permanent einselection, this delays the emergence of the pointer basis due to accumulated negativity.