| name | fisher-glasses-tail-certified-metrology |
| description | Tail-certified quantum metrology for quenched sensors — Fisher-zero integrability transition, no-go theorem on averaged Fisher data, universal design laws (safe windows, nondegenerate portfolios, Fisher reserves, Fisher-cut criteria). Activation: quantum metrology, Fisher information, quenched environments, tail certification, NV centers, superconducting qubits, Fisher glass, QFI certification |
| metadata | {"arxiv_id":"2607.01085","published":"2026-07-01","authors":"El Mustapha Mansouri, Keigo Arai"} |
Fisher Glasses: Tail-Certified Quantum Metrology
Overview
Quantum metrological advantage certified by averaged Fisher responses (contrast, susceptibility, QFI) fails in quenched sensors where slow environmental variables freeze within a session but vary between repetitions.
Key Contributions
No-Go Theorem
No averaged Fisher data determine quenched certification. Ensembles sharing averaged Fisher matrix, QFI, and projected information can have finite or zero certified precision.
Fisher-Zero Integrability Transition
- The inverse-loss tail exponent β sets the boundary
- Nonintegrable certified loss for β ≤ 1, even when annealed information is large or scaling
- Certified quantum resource is response transverse to latent disorder, not raw amplification
Universal Design Laws
- Safe windows: Operating regimes where certification is reliable
- Nondegenerate portfolios: Measurement configurations avoiding degeneracy
- Fisher reserves: Buffer capacity for certification robustness
- Action separation: Distinguishing signal from latent disorder
- Fisher-cut criteria: Threshold for meaningful certification
Experimental Validation
Shallow-NV Ramsey tournament: average-QFI optimization is tail-catastrophic, whereas tail-certified designs recover nearly three orders of magnitude in certified information at equal shot budget.
Applicable Systems
- Shallow NV centers
- Superconducting qubits with slow two-level fluctuators
- Semiconductor spin qubits in drifting charge noise
Pitfalls
- Optimizing average QFI can be tail-catastrophic — use tail-certified designs instead
- The Fisher-zero rare-event statistics govern the Fisher glass phase
Related Skills
quantum-metrology-sensing-review — broader quantum metrology reviewfinite-shot-quantum-metrology — finite-measurement metrology theoryquantum-fisher-information-duality — QFI duality framework
References
- arXiv: 2607.01085 — "Fisher Glasses: Tail-Certified Quantum Metrology in Quenched Environments"
