Energy Equilibrium Manifold for Qubit Coherence Stabilization in Gaussian-Coupled Field Models

This revised version (v1.1) introduces several major improvements compared to the previous release: 1. Added a physically consistent open-system model The qubit–bosonic–mode system is now described using a full Lindblad master equation, including: relaxation (T1), non-geometric dephasing, bosonic-mode damping, realistic mode–reduction from a Gaussian scalar field. This makes the model experimentally testable and physically grounded. 2. New coherence-stabilization mechanism validated in an open system We demonstrate that the proposed Energy-Balance Manifold(Δlog⁡=0) acts as a true coherence sweet-spot,even when dissipation is present. The previous version only discussed this at a conceptual level. 3. Improved numerical simulations All figures have been recomputed using the new codebase: 2D manifold maps, analytic suppression law, 3D coherence surface, Ramsey and Spin-Echo simulations. All numerical scripts are now included in /Code and all datasets in /Data,making the results fully reproducible. 4. Added figure references, cross-citations and expanded physical explanation The manuscript now contains: figure-by-figure captions, in-text references to Figures 1–10, an expanded physical motivation for the bosonic-mode reduction, a new section 4.5 Open-System Extension and Realistic Decoherence Channels. 5. Complete package archive with checksums The ZIP now contains: report, code, figures, data, checksum file, README file. This enables independent verification of all results.