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Phase 3 Entanglement/Tomography IBM Execution Package

Date: 2026-05-20

Decision

  • Campaign: reduced-Pauli entanglement/tomography follow-up.
  • Backend preflight target: ibm_marrakesh.
  • Live preflight artefact: data/phase3_entanglement_tomography/entanglement_tomography_live_ibm_marrakesh_2026-05-20T001956Z.json.
  • Completed execution artefact: data/phase3_entanglement_tomography/entanglement_tomography_live_ibm_marrakesh_2026-05-20T004334Z.json.
  • Status: completed.
  • Hardware submission performed: True.
  • Job IDs: d86g7h1789is738vkreg, d86ggpis46sc73f6v170.

Live Preflight Summary

Field Value
Main circuits 162
Readout circuits 4
Total circuits 166
Main shots 2048
Readout shots 8192
Estimated QPU minutes 1.5217
Budget ceiling minutes 25.0
Selected physical qubits [1, 2, 3, 4]
Mean readout error 0.005584716796875
Backend pending jobs 0
Maximum transpiled depth 388
Maximum basis-expansion ratio 1.0718232044198894

The preflight passed the preregistered guards: the circuit count remains below the DLA+FIM ceiling, estimated QPU time remains below the budget ceiling, and measurement-basis expansion remains below the 1.20 depth-ratio guard.

Execution Commands

Live readiness only:

python scripts/phase3_entanglement_tomography_ibm.py --backend ibm_marrakesh

Approved QPU submission:

python scripts/phase3_entanglement_tomography_ibm.py --backend ibm_marrakesh --submit --confirm-budget

Post-run raw-count analysis:

python scripts/analyse_phase3_entanglement_tomography.py \
  data/phase3_entanglement_tomography/entanglement_tomography_live_<backend>_<timestamp>.json

First-Pass Analysis

Post-run analysis produced:

  • JSON summary: data/phase3_entanglement_tomography/entanglement_tomography_summary_2026-05-20.json
  • Observable rows: data/phase3_entanglement_tomography/entanglement_tomography_rows_2026-05-20.csv
  • Manifest: docs/campaigns/phase3_entanglement_tomography_manifest_2026-05-20.md

Result snapshot:

Metric Value
Observable rows 54
Mean absolute deviation from exact reference 0.12989296537986128
Maximum absolute deviation from exact reference 0.5560906424788263
Rows SHA256 3d18308d60fe32827bae7517f18fd71690240b105779287408c4749cb0e7dc72

Paper Spin

Working title:

Reduced-Pauli entanglement checks for DLA-sector leakage mechanisms on IBM Heron hardware

Core result class:

  • compare measured reduced-Pauli correlators against exact classical references for the promoted DLA parity and FIM-pair circuits;
  • report whether the leakage/retention mechanism has a measurable entanglement-structure companion;
  • include a null or negative result as a bounded measurement-cost and mechanism-separation result.

Blocked claims:

  • quantum advantage;
  • scalable tomography;
  • backend-general entanglement dynamics;
  • full-state reconstruction;
  • claims on unmeasured subsystems, unmeasured depths, or unmeasured backends.

Paper-facing artefacts:

  • Plan: docs/campaigns/phase3_entanglement_tomography_paper_plan_2026-05-20.md
  • Canonical LaTeX source: paper/submissions/submission_005_phase3_reduced_pauli_entanglement/phase3_entanglement_tomography.tex
  • Built PDF: paper/submissions/submission_005_phase3_reduced_pauli_entanglement/phase3_entanglement_tomography.pdf
  • Historical Markdown scaffold: paper/submissions/submission_005_phase3_reduced_pauli_entanglement/phase3_entanglement_tomography_short_paper.md

Completed Extensions

The initial execution package was extended on the same date with second-backend replication, pinned-layout full correlated readout calibration, and a preregistered five-channel ZNE stress test on ibm_fez.

Extension artefacts:

  • data/phase3_entanglement_tomography/entanglement_tomography_live_ibm_fez_2026-05-20T014536Z.json
  • data/phase3_entanglement_tomography/entanglement_tomography_live_ibm_fez_2026-05-20T020452Z.json
  • data/phase3_entanglement_tomography/entanglement_tomography_live_ibm_fez_2026-05-20T023204Z.json
  • data/phase3_entanglement_tomography/entanglement_tomography_live_ibm_fez_2026-05-20T023600Z.json
  • data/phase3_entanglement_tomography/entanglement_zne_summary_2026-05-20_ibm_fez_zne.json
  • docs/campaigns/phase3_entanglement_zne_manifest_2026-05-20_ibm_fez_zne.md

Extension jobs:

  • backend replication and full-readout calibration: d86hdk8p0eas73dkv9eg, d86hedp789is738vm7mg
  • ZNE subset and 16-state readout calibration: d86hs6qs46sc73f70h90, d86hsltg7okc73el4lg0

ZNE snapshot:

Metric Value
ZNE scale rows 15
ZNE channels 5
Scale-1 mean absolute deviation 0.4196274906488838
Linear-ZNE mean absolute deviation 0.44124749932943935
Full-readout-mitigated linear-ZNE mean absolute deviation 0.4468173734963394
Quadratic-ZNE mean absolute deviation 0.4477931807530503

The ZNE extension is interpreted as a mechanism stress test only. The simple global-folding lane does not erase the four dominant DLA transverse deviations; the FIM control channel behaves differently and improves under linear extrapolation.

Boundary

This package records a completed, approved QPU submission and first-pass reduced-Pauli analysis. It supports only the bounded claim that measured small-system reduced-Pauli correlators deviate from exact references under the specified backend, layout, circuit family, shots, repetitions, and calibration window. It does not support scalable tomography, quantum advantage, or backend-general entanglement dynamics.