Decoherent histories with(out) objectivity in a (broken) apparatus
Quantum Physics
2026-03-23 v4 Statistical Mechanics
Abstract
We characterize monitored quantum dynamics in a solvable model exhibiting a phase transition between a measurement apparatus and a scrambler. We show that approximate decoherent histories emerge in both phases with respect to a coarse-grained extensive observable. However, the apparatus phase, where quantum Darwinism emerges, is distinguished by the non-ergodicity of the histories and their correlation with the measured qubit, which selects an ensemble of preferred pointer states. Our results demonstrate a clear distinction between two notions of classicality, decoherent histories and environment-induced decoherence.
Keywords
Cite
@article{arxiv.2508.16482,
title = {Decoherent histories with(out) objectivity in a (broken) apparatus},
author = {Benoît Ferté and Davide Farci and Xiangyu Cao},
journal= {arXiv preprint arXiv:2508.16482},
year = {2026}
}
Comments
13 pages, 4 figures; v3: approximately matching published version