2026.03.31__Operational_Recoverability_Metrics_for_Open_Quantum_Systems:_An_EIC-Based_Diagnostic_Framework
Koizumi Takao
This paper introduces an operational framework for quantifying reconstructability in open quantum systems under realistic conditions involving noise, measurement, and recovery processes. While decoherence theory explains the suppression of interference due to system–environment interactions, it does not directly address whether quantum states remain reconstructable in practice. To bridge this gap, this work proposes the Recoverability Index (RI), a scalar diagnostic that quantifies how close a system remains to reconstructable dynamics. The RI integrates three key components: recovery fidelity, entropy-like proxies of environmental information dispersal, and distinguishability of environmental records. Unlike traditional approaches that focus on coherence loss, this framework emphasizes reconstructability as an operational criterion, enabling a practical distinction between recoverable and effectively irreversible regimes. A simplified quantum error correction (QEC) scenario is used to demonstrate the applicability of the RI. The results show that the RI provides a transparent and interpretable metric for comparing noise conditions, evaluating recovery performance, and identifying boundaries of reconstructability. This work does not propose a new fundamental theory of quantum measurement. Instead, it offers a tool-oriented extension of the Entropy-Induced Collapse (EIC) framework, focusing on measurable quantities and practical diagnostics. The Recoverability Index serves as a bridge between conceptual descriptions of irreversibility and actionable evaluation in experimental and computational quantum systems. Keywords: quantum decoherence, quantum error correction, recoverability, irreversibility, open quantum systems, quantum information
•Mar 31, 2026•0 citations