Synchronisation witnesses

scpn_quantum_control.phase.synchronisation_witness evaluates bounded phase clouds with two complementary signals: harmonic Kuramoto order parameters and exact Vietoris–Rips persistence over circular geodesic distances. The default suite contains deterministic synchronised, uniformly desynchronised, and three-cluster reference regimes.

What the suite certifies

The first harmonic measures global phase alignment. The second harmonic can reveal anti-phase or two-cluster structure that the first harmonic cancels. Persistent homology supplies component counts and loop lifetimes across an explicit filtration grid. Bootstrap perturbations estimate local uncertainty in the first-harmonic order parameter.

The implementation performs exact boundary-matrix reduction over GF(2) for small phase clouds. It supports homology dimensions zero and one. It is not an accelerated persistence kernel or a general high-dimensional topology engine.

Reference suite

from scpn_quantum_control.phase import run_sync_witness_suite


suite = run_sync_witness_suite()
assert suite.passed
for record in suite.records:
    print(
        record.case_id,
        record.regime,
        record.order_parameter,
        record.persistent_component_count,
        record.dominant_h1_persistence,
    )

Every result carries an evidence classification and a claim boundary. Boundary rows keep high-dimensional manifold inference and provider-backed hardware phase tomography explicitly closed.

Evidence artefacts

The evidence writer serialises the reference records, boundary rows, environment metadata, schema, and promotion flags to matching JSON and Markdown files:

PYTHONPATH=src:. python scripts/export_sync_witness_evidence.py

The committed examples are data/differentiable_phase_qnode/sync_witness_evidence_20260709.json and .md. They are deterministic local synthetic evidence. They do not establish device performance, provider execution, phase tomography, isolated timing, or production eligibility.

For exact signatures and fields, see the Synchronisation witness API.