State objectivity and information scrambling in realistic qubit-bosonic systems
Phys. Rev. A 114, 042424 – Published 13 October, 2026
DOI: https://doi.org/10.1103/ry8r-1ts9
Abstract
We explore the relationship between state objectivity (in the sense of strong quantum Darwinism) and information scrambling for a qubit interacting with a bosonic environment. Using accessible tripartite information (ATI) and standard tripartite mutual information (TMI), we verify that TMI may fail to reliably quantify scrambling, since it does not separate classically accessible correlations from quantum contributions. In contrast, ATI properly identifies scrambling by focusing on operationally accessible classical information, as argued by G. L. Monaco et al. [Quantum Sci. Technol. 8, 035006 (2023)]. Our central results reveal a clear dynamical association: genuine objectivity is observed together with positive ATI (no scrambling), whereas negative ATI (scrambling) is accompanied by the absence of objective records, even in the presence of standard quantum Darwinistic behavior. A time-resolved comparison further shows that the absence of redundant accessible records persists at later stages of the dissipative evolution as the magnitude of the negative ATI decreases, supporting a dynamical association rather than a causal relation between scrambling and the lack of genuine objectivity. We also observe that standard quantum Darwinistic behavior can coexist with positive TMI even when redundant accessible records are absent. By investigating both pure-dephasing and dissipative dynamics in Markovian and non-Markovian regimes, we show that quantum Darwinism can emerge even under non-Markovian dynamics, while genuine objectivity has no universal connection with non-Markovianity. This work highlights the significance of strong quantum Darwinism and ATI, and deepens the understanding of objectivity, information scrambling, and the quantum-to-classical transition in realistic open quantum systems.