WP-E Progress — Logbook

Logbook — 2026-04-14 — Flag 1 closed: synced-phase convention → comb lineshape

2026-04-14-flag1-synced-phase.md

Context. The user's statement "Phase is kept synced for all pulses of a train" (2026-04-14) closes Flag 1 from 2026-04-13-flag-reruns.md §3. Under the synced-phase convention, the laser/AC phase reference is maintained across the full pulse train, and the spin picks up exp(−i·(δ/2)·σ_z·T_gap) per inter-pulse gap.

Logbook — 2026-04-14 — AOM erf-envelope softens v0.9.1 corrections

2026-04-14-aom-envelope.md

Context. Sequel to 2026-04-14-flag1-synced-phase.md. User authorised: τ_rise ≈ 50 ns typical, erf/Gaussian edge, driver-level wrapper. This entry swaps the rectangular pulse for an erf-shaped envelope and measures the effect on lineshape, |C|(φ_α) spread, and the γ-corrections.

Logbook — 2026-04-14 — 2D scan at |α|=3 without synced-phase (engine native)

2026-04-14-2d-scan-unsynced.md

Context. User request: "do the same without synced-phase". Same grid as 2026-04-14-2d-scan-alpha3.md (±15 MHz × [0, 2π), |α| = 3, 1001 × 64 pts) under the engine's native v0.9.1 convention instead of synced-phase.

Logbook — 2026-04-14 — 2D scan at |α|=3, ±15 MHz × [0, 2π): sideband envelope is the velocity signature

2026-04-14-2d-scan-alpha3.md

Context. User request: spin contrast as a function of motional phase (0 → 2π) and analysis-pulse detuning (±15 MHz) at fixed |α| = 3. First wide-range detuning scan under the synced-phase convention (2026-04-14-flag1-synced-phase.md).

Logbook — 2026-04-13 — WP-E v0.3 decisions

2026-04-13-v0.3-decisions.md

Context. WP revised from v0.2 → v0.3 incorporating Guardian v0.2 and external v0.2 reviews. This entry records the decisions taken on Q0–Q8, the preflight protocol specification, and the Hamiltonian-code line that fixes the φ_α sign convention.

Logbook — 2026-04-13 — Preflight results

2026-04-13-preflight-results.md

Context. Follow-up to 2026-04-13-preflight-kickoff.md. Executes the §4a protocol of ../README.md (v0.3). Scope: single-anchor cross-engine validation at (δ₀ = 0, |α| = 0, φ_α = 0); resolution of the Q3 and Q5 residual questions; S1/S2/S3 budget estimate.

Logbook — 2026-04-13 — Preflight kickoff

2026-04-13-preflight-kickoff.md

Context. Guardian cleared v0.3 for execution. This entry opens §4a preflight and codifies five residual Guardian flags as operational requirements before any numerics runs. Sequel entry: 2026-04-13-preflight-results.md will record outcomes.

Logbook — 2026-04-13 — Guardian Flag 2 + Flag 3 reruns; Flag 1 correspondence stub

2026-04-13-flag-reruns.md

Context. Guardian's R2-review (stance closed on R2-comb.md) flagged three items before v0.4: (2) the R2 coarse grid undersamples the tooth width and the between-tooth value of 0.033 is grid-limited, not physical; (3) the full-engine carrier-bias at −0.20 MHz/(2π) may be grid aliasing — should settle with a high-resolution carrier zoom; (1) the claim "the engine's convention matches the Hasse2024 experiment" overstates what the data support and needs experimental-team confirmation. This entry closes Flags 2 and 3 and stages Flag 1.

Logbook — 2026-04-13 — arg C identity under v0.9.1: survives as leading order

2026-04-13-arg-C-under-v0.9.md

Context. The S2-revisited entry (2026-04-13-S2-revisited-under-v0.9.md) established that the |C| φ_α-independence theorem breaks under D1 at the 5% level. It did not explicitly test the companion identity arg C(δ_0=0, φ_α) = 90° + 2η|α|·cos φ_α that the same S2 falsification entry reported exact to 10⁻¹¹ deg RMS under v0.8. This entry closes that test.

Logbook — 2026-04-13 — Architect-stance note: WP-E renaming before v0.4

2026-04-13-architect-renaming.md

[Stance: Architect] — the design question Guardian raised twice and the v0.3 framing cannot carry unchanged into v0.4.

Logbook — 2026-04-13 — S2 revisited under engine v0.9.0

2026-04-13-S2-revisited-under-v0.9.md

Context. Sequel to 2026-04-13-S2-falsification.md. That entry proved the matrix-element-magnitude theorem |⟨α|C|α⟩| = exp(−η²/2) and concluded that |C| is φ_α-independent for coherent states under the stroboscopic protocol. Falsification was at machine precision (worst Δ|C| = 6.6 × 10⁻¹³).

Logbook — 2026-04-13 — S2 sheet at |α|=3 — falsification of the Doppler-broadening hypothesis

2026-04-13-S2-falsification.md

Context. Sequel to 2026-04-13-S1-plots.md. Guardian explicitly invited the test: "if [the |α|·|sin φ_α| broadening prediction] fails: stop, post a logbook entry naming the failure mode." It failed. The mechanism is now understood and is more interesting than the failed prediction would have been.

Logbook — 2026-04-13 — S2 expansion (|α|=1, 5) + H1 Floquet lock-tolerance + correction to S2-falsification

2026-04-13-S2-expansion-and-H1.md

Context. Guardian cleared the falsification and recommended: (i) S2 sheets at |α| ∈ {1, 5} to complete the arg C(|α|, φ_α) map; (ii) H1 (Floquet lock-tolerance) promoted as the cheapest protocol- identity test; (iii) an unwrapped arg C panel; (iv) explicit arg C(|α|, φ_α) S3-replacement. All four done in this entry. One self-correction to the previous falsification logbook is also issued.

Logbook — 2026-04-13 — S1 plots, with one new physics observation

2026-04-13-S1-plots.md

Context. Plots for the S1 + R1 dataset of 2026-04-13-S1-and-R1.md, generated by ../numerics/plot_S1.py. One new observation surfaces from looking at the maps that was not visible from the carrier-only analysis: the φ_α = 0 slice is Doppler-blind for the contrast magnitude, with consequences for S2 priority.

Logbook — 2026-04-13 — S1 slice + R1 reference + R1 convergence check

2026-04-13-S1-and-R1.md

Context. Follow-up to 2026-04-13-preflight-results.md. Guardian cleared preflight; this entry reports the first WP-E data: S1 slice ((δ₀, |α|) at φ_α = 0), the R1 reference (η = 0.04) on the same grid, and a one-off R1 convergence cross-check (η = 0.04 vs η = 0.02) per Guardian flag 1.

Logbook — 2026-04-13 — R2 reference reveals a frame-convention choice, not a simple limit

2026-04-13-R2-comb.md

Context. Sequel to 2026-04-13-S2-expansion-and-H1.md. R2 is the instantaneous-pulse (δt → 0) reference per v0.3 §3.1 / §8 Q3. Implemented as impulsive kicks with explicit inter-pulse spin free evolution for duration T_m at detuning δ — the Monroe-like picture. Ran it. The result is physically interesting but not the "small Δt correction" the v0.3 decomposition implicitly assumed.