Quantum control practice runs on characterisations: measured coherence times, gate errors, frequencies, and crosstalk figures, taken at calibration and consumed by every layer of the control stack until the next calibration replaces them. A premise rides silently in that consumption — that the characterisation remains current between calibrations — and this paper examines and refuses it. We argue three points, each held at its own strength. First, a characterisation is a finite observer's estimate, not a standing fact: at calibration time it already carries a strictly positive uncertainty floor from finite probes, and the act of probing is itself a physical intervention on the device. Second, between calibrations the device's parameters move — relaxation times fluctuate on hour scales through two-level-system dynamics, and environmental drift reshapes the error landscape — so the uncertainty a consumer should attach to a characterisation widens with time since calibration under any honest model. Third, these two facts compose into a limit with an operational consequence: under the declared drift model a characterisation carries a finite validity horizon, and in every case it carries expiry semantics — a control stack that consumes a characterisation without an expiry is acting on an unexamined exactness claim. The finite horizon is conditional and the finite-calibration limit section states its converse: a mean-reverting drift confined within tolerance admits an infinite horizon, and nothing here forbids that case. We then instantiate the external contract of the companion limits paper for this setting: a characterisation ships with a declared validity budget and a declared expiry model; consumers check validity before acting on it; and on expiry the fail-closed forms are refusal of the stale figure and escalation to recalibration with a declared deadline. We state a minimal stochastic validity model — latent device state, calibration posterior, hazard-widening between calibrations, derived expiry rule — as a declared model whose parameters an installation must estimate, not a law derived here. The authority boundary of the resulting layer is advisory by design choice, and we give the rationale rather than presenting the choice as a consequence. Related work has built the detection and tracking instruments this contract would consume; what is added here is the register those instruments lack: validity as a first-class, expiring, refusable claim.
Quantum control practice runs on characterisations: measured coherence times, gate errors, frequencies, and crosstalk figures, taken at calibration and consumed by every layer of the control stack until the next calibration replaces them. A premise rides silently in that consumption — that the characterisation remains current between calibrations — and this paper examines and refuses it. We argue three points, each held at its own strength. First, a characterisation is a finite observer's estimate, not a standing fact: at calibration time it already carries a strictly positive uncertainty floor from finite probes, and the act of probing is itself a physical intervention on the device. Second, between calibrations the device's parameters move — relaxation times fluctuate on hour scales through two-level-system dynamics, and environmental drift reshapes the error landscape — so the uncertainty a consumer should attach to a characterisation widens with time since calibration under any honest model. Third, these two facts compose into a limit with an operational consequence: under the declared drift model a characterisation carries a finite validity horizon, and in every case it carries expiry semantics — a control stack that consumes a characterisation without an expiry is acting on an unexamined exactness claim. The finite horizon is conditional and the finite-calibration limit section states its converse: a mean-reverting drift confined within tolerance admits an infinite horizon, and nothing here forbids that case. We then instantiate the external contract of the companion limits paper for this setting: a characterisation ships with a declared validity budget and a declared expiry model; consumers check validity before acting on it; and on expiry the fail-closed forms are refusal of the stale figure and escalation to recalibration with a declared deadline. We state a minimal stochastic validity model — latent device state, calibration posterior, hazard-widening between calibrations, derived expiry rule — as a declared model whose parameters an installation must estimate, not a law derived here. The authority boundary of the resulting layer is advisory by design choice, and we give the rationale rather than presenting the choice as a consequence. Related work has built the detection and tracking instruments this contract would consume; what is added here is the register those instruments lack: validity as a first-class, expiring, refusable claim.
A companion paper reported a fail-closed estimator — the Quantum Control Kernel (QCK) — that detects the precursor of systematic bias drift in cryogenic quantum control before actuator saturation, validated in simulation and against live, publicly accessible IBM hardware-calibration data. This paper reports what the estimator is for: the Quantum Control Architecture (QCA), a governed measurement-and-control layer in which the demonstrated kernel is the sensing floor of a larger construction. The construction is not free design. It is the quantum instantiation of a result established generically in the Finite Cognition series: a finite observer serving both a committing execution demand and a wide-field vigilance demand is forced to partition the two and re-couple them at the point of finalisation, so that no output is committed that vigilance has not verified. We show that quantum control information forces exactly this construction — telemetry is consumed by every layer of the control stack yet governed by none of them; observation of a quantum plant must be non-perturbative by discipline, not by hope; and an estimator that is fluent but ungoverned reproduces, on the control substrate, the same confident-and-blind failure the series identified generically. We then state the architecture that discharges the constraint, in its public units: a non-perturbative observer (NPO); the QCK detection floor; fail-closed gates that allow, abstain, or refuse; a state-coherence and equilibrium discipline over commits; provenance-checked memory that refuses known-failure patterns; a lifecycle and loop supervisor; a measurement plane of stability, coupling, margin, and cost features; and an integrity plane that audits the architecture’s own calibration model and gates its portability to new hardware on provably leak-free relocation. We are explicit about maturity throughout: the kernel is demonstrated at Technology Readiness Level 4 under published bounds; the architecture beyond it is compile-ready geometry — derived, specified, and internally consistent, not validated as live middleware on partner hardware. The architecture is advisory by construction: the operator owns the plant at every depth.
A companion paper reported a fail-closed estimator — the Quantum Control Kernel (QCK) — that detects the precursor of systematic bias drift in cryogenic quantum control before actuator saturation, validated in simulation and against live, publicly accessible IBM hardware-calibration data. This paper reports what the estimator is for: the Quantum Control Architecture (QCA), a governed measurement-and-control layer in which the demonstrated kernel is the sensing floor of a larger construction. The construction is not free design. It is the quantum instantiation of a result established generically in the Finite Cognition series: a finite observer serving both a committing execution demand and a wide-field vigilance demand is forced to partition the two and re-couple them at the point of finalisation, so that no output is committed that vigilance has not verified. We show that quantum control information forces exactly this construction — telemetry is consumed by every layer of the control stack yet governed by none of them; observation of a quantum plant must be non-perturbative by discipline, not by hope; and an estimator that is fluent but ungoverned reproduces, on the control substrate, the same confident-and-blind failure the series identified generically. We then state the architecture that discharges the constraint, in its public units: a non-perturbative observer (NPO); the QCK detection floor; fail-closed gates that allow, abstain, or refuse; a state-coherence and equilibrium discipline over commits; provenance-checked memory that refuses known-failure patterns; a lifecycle and loop supervisor; a measurement plane of stability, coupling, margin, and cost features; and an integrity plane that audits the architecture’s own calibration model and gates its portability to new hardware on provably leak-free relocation. We are explicit about maturity throughout: the kernel is demonstrated at Technology Readiness Level 4 under published bounds; the architecture beyond it is compile-ready geometry — derived, specified, and internally consistent, not validated as live middleware on partner hardware. The architecture is advisory by construction: the operator owns the plant at every depth.
Cryogenic control electronics accumulate systematic, non-zero-mean bias — from thermal cycling of mounts, flux leakage, and dielectric memory — that a feedback loop integrates until its actuator authority is exhausted and the integrator saturates. A controller that alarms on amplitude thresholds sees this failure only after correction is no longer available. This paper reports a precursor estimator that reads the dynamics of the control signal for the onset of systematic drift, built deliberately as a finite observer in the sense of the first Finite Cognition paper: a declared error budget, an explicit competence boundary, and fail-closed abstention. Its evidence is presented in two declared strata. First, a fresh, fully archived Monte-Carlo run of record on a declared control-loop model: across 30 seeds × 7 sensor-environment conditions × two drift polarities, with every threshold frozen before the batch, the estimator detected drift before saturation in 246/354 eligible collapse runs (69.5%, 95% interval 64.5–74.1%), with per-condition detection ranging from 25.5% (all disturbances combined) to 100% (dropout; 92.4–100), median leads of 7–17 s, and zero false interdicts across 210 healthy runs within the declared calibration window (0.0–1.8%) — a bound the long-horizon batch shows is conditional on the mandated recalibration schedule. Second, an archived read of live IBM quantum-hardware calibration telemetry (a 156-qubit Heron device, June 2026): the same governed detector family flagged the two genuinely degraded qubits and the sole sustained relaxation-time decline within that window (T_1 falling 88.0 → 19.1 µs across 43 returned calibration snapshots spanning 42 calendar days) — an event a longer archived record later resolves into the first, longest and deepest of four recurring excursions on the same qubit, at a cost to this detector family the paper states while staying silent on a bad-but-stable qubit and the 154 others. The estimator holds advisory-only authority under the programme's interface contract: it emits verdicts and writes nothing to the plant. This record supersedes an earlier version whose simulation table could not be traced to a quantum-specific run; the run of record reported here, code and data archived, is the evidence this paper stands on.
Here's what this paper means for actual humans: WHAT THIS IS ABOUT. When you build or use a quantum device, everything rests on knowing what its parts are: which degrees of freedom are "qubit 1," which are "qubit 2." The companion paper ("Forged Frames") showed that simple mathematical criteria cannot certify this; convincing fakes exist. This paper answers the question that result leaves standing: what is the MINIMUM experimental information that genuinely pins down a system's subsystem structure, and when can that information silently fail? WHAT WE FOUND, IN PLAIN TERMS. Four things. (1) EXACT LAWS INSTEAD OF MEASUREMENTS. Any wrong choice of parts must visibly distort the family of unentangled states, and we derive exactly how much, at every system size: closed-form constants (verified to seven decimal places), an explicit error bound, and a surprise. The two natural ways to measure "wrongness" (state distortion versus operator scrambling) turn out to be literally the same measurement, up to a fixed number, whenever the two parts have equal size. Wrongness cannot hide. (2) THE TWO-OPERATION THRESHOLD. You can pin down what your subsystems are by implementing just TWO generic operations and checking their statistics, while a THOUSAND mutually commuting operations tell you nothing at all. Diversity of control, not volume of control, is what fixes what your qubits are. The residual uncertainty is proportional to your measurement tolerance, with a constant we derive exactly and show how to compute in advance, so an experimenter can screen candidate operation pairs and pick a strong one (random pairs are typically several times worse, occasionally catastrophically so). (3) THE ALIASING LIMIT: CERTIFICATION CAN PASS WHILE TELLING YOU NOTHING. If you sample your certification data at special "resonant" times (set by the operations' energy scales), a maximally wrong assignment of subsystems passes the test perfectly. What your qubits are depends on when you looked. We characterize these blind spots exactly (for qubits they are universal and computable in advance; the danger windows shrink with the square root of your tolerance), and the fix costs almost nothing: sample at two different times, at least one away from the resonant set. With that, certification is restored; we prove it exactly and measure it. (4) REAL-LAB BUDGETS. We work out what certification costs in actual measurement shots (the error falls off unusually fast, inversely with the total number of shots rather than with its square root), how hardware noise floors the procedure, and how a simple reference measurement removes that floor to first order. A single seven-row table in the paper is effectively a lab protocol: it shows, condition by condition, which kinds of experimental access identify the subsystem structure (two generic operations: yes; one operation, commuting operations, resonant sampling: no). WHY IT MATTERS. For quantum hardware: this is a concrete recipe for certifying that the qubits you think you have are the qubits you physically have, with explicit tolerances, a sampling-time warning that is a real failure mode on calibrated hardware, and shot budgets. For foundations: the contested question "does physics determine its own subsystems?" gets a quantitative operational answer. Physics determines an operational subsystem CLASS (not one preferred coordinate representation of it), and that class is fixed by two operations sampled at two times, and by nothing less that we tested. WHAT IT OPENS UP. The seven-row identifiability table is a blueprint for a tabletop experiment on any small quantum platform; running it on hardware would move this from simulation to laboratory fact. On the theory side the paper leaves sharply posed open problems: the exact global constants when the two parts differ in size, the number-theoretic structure of long-time sampling (the failure times form a small-divisor hierarchy), and the extension from two parts to many. METHODS NOTE, BECAUSE IT MATTERS FOR TRUST. Every quantitative claim was pre-registered in the companion scripts before its run. The full ledger, including predictions that failed and one published-in-note constant that our own later theory overturned, is an appendix of the paper. All code, data, and working notes are in the deposit, seeded for exact reproduction. WHO AND HOW. A human-AI collaboration: research direction and standards of evidence by Ryan Cardwell (Crystalline Labs); design, code, derivations, and drafting by Claude (Anthropic), including autonomous sessions under the program's pre-registration rules, with adversarial reviews by other AI models incorporated and credited.
Cryogenic control electronics for quantum hardware accumulate systematic, non-zero-mean bias that integrates in a feedback loop until the actuator saturates; a threshold controller detects this only after saturation. We present a precursor estimator that detects the onset of systematic drift from the dynamics of the control signal, built as a finite observer (declared error budget, explicit competence boundary, fail-closed abstention) in the sense of a companion paper on the physical limits of finite observation. It uses path-functional invariants (a Fisher–Rao metric stability bound, a maximum-likelihood bias decoder, a cumulative-damage functional) rather than eigenvalue analysis, which we show is neither necessary nor sufficient for finite-time survival. In simulation, across 30 seeds × 7 sensor-environment conditions (including a 1/f dephasing spectrum), it detects 96.7% of drift-collapse scenarios before saturation at a 12 s median lead with 0% false positives over 210 healthy runs. On real data, the same governed outlier-and-drift detector, applied to live publicly accessible IBM quantum-hardware calibration time-series (a 156-qubit IBM Heron device), flags genuinely degraded qubits and catches a real relaxation-time decline (one qubit's T1 falling 88.0→19.1 µs, −78%, over 43 days) while staying silent on a qubit that is poor but stable and on the other 155 — detection of change, not of mere badness. The work is TRL 4: an advisory detection layer, not a deployed controller, and it does not emulate entanglement, non-local correlation, or contextuality. The contribution is the integrated, calibrated estimator and its operating discipline, demonstrated in simulation and against real hardware-calibration data.
We construct a source-matched reference calibration for distinguishing the coherent law h = 0 from the specified added generator h = J/25 in a finite quantum-record model. A complete-carrier transfer bound connects an accessible reference contrast to a delayed target contrast while retaining the original drift and actual law. On reference coverage and measured admission, restricting both hypotheses by the same observed reference band yields a directed target-set separation of at least 0.0071230619 whenever both compatible classes are nonempty. Rival worlds may have different admitted nuisance parameters. The constants are uniform over independently known finite lengths m >= 65, with tag 65, access prefix 1:32 and target deadline 25.02/J. Finite reference preparation and work/source reset satisfy the declared response budgets. Reset acts on the actual joint input and consumed supply, with the retained reference R exactly inert. It does not assign a universal reduced channel to correlated supplies. Under almost-sure conditional resource and supply bounds, the comparison extends to history-dependent acquisition. A prespecified rule, including abstention below the calibration threshold, has each-law unconditional wrong-declaration probability at most 2 exp(-6) + exp(-85/16) < 0.01. This is neither a posterior probability nor an error bound conditional on admission. The statistical step uses standard bounded-martingale concentration. Global target states and specified auxiliary supplies remain resources. Reset requires additional globally conditioned controls and has very large finite costs. The result is a conditional theorem for the two declared laws; it does not establish practical implementation or a unique diagnosis of fundamental collapse. A supporting Lean 4 companion contains 85 theorem declarations and 30 supporting definitions across Calibration, Operations and Risk. It provides checked scalar, sufficient-bound, resource-arithmetic and finite-history risk consequences under explicit premises. The companion has an executed Linux preflight and accepted returned macOS compilation, named-type and transitive-axiom evidence. The quantum constructions and conditional moment, filtration, tower and tail derivations remain written proofs or external premises; this is not an end-to-end formalization of the physical theorem chain. The original checked companion targeted author v0.4 and is carried forward unchanged, with its scope and execution chronology preserved.