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GUESS / Symmetry-Decay Calibration Preregistration

Date: 2026-05-06

This preregistration prepares a hardware GUESS / symmetry-decay validation using parity leakage as a witness. It does not submit IBM jobs, reserve backend time, or authorise QPU spend.

Readiness Basis

The no-QPU readiness analysis is:

data/phase2_guess_calibration/phase2_guess_calibration_summary_2026-05-05.json

It fits log parity survival versus circuit depth as a cumulative-noise proxy. It is not zero-noise extrapolation, because the promoted Phase 2 datasets do not contain explicit folded-noise scale factors or another controlled noise knob.

Readiness signal:

  • Phase 2 A+G even, odd, and sector-mean series have R2 >= 0.9989.
  • Popcount-control state fits have R2 from about 0.958 to 0.992.
  • These fits justify preparing a folded-noise protocol, not claiming GUESS mitigation from existing data.

Scientific Question

Can parity leakage serve as a stable hardware symmetry-decay witness for symmetry-guided zero-noise extrapolation on the same heterogeneous Kuramoto-XY family?

Claim Boundary

Supported after successful execution and analysis:

  • calibrated relationship between explicit noise scale and parity survival;
  • comparison between standard extrapolation and symmetry-decay guided extrapolation for the selected observable;
  • statement that the witness is or is not stable enough for the tested backend/circuit family.

Blocked even after a positive result:

  • broad quantum advantage;
  • universal error mitigation;
  • backend-general GUESS performance;
  • DLA-parity-only protection;
  • transfer of fitted coefficients to a different backend, layout, or calibration window without new validation.

Circuit Matrix

Default scope:

Field Value
n 4
States 0011 even reference, 0001 odd reference
Depths 6, 8, 10, 14
Noise scales 1, 3, 5 via explicit unitary folding or approved equivalent
Repetitions 8 per state/depth/noise-scale
Main shots 4096 per circuit
Readout states 0011, 0001, 0000, 1111
Readout shots 8192 per circuit

Circuit count:

  • main circuits: 2 states x 4 depths x 3 noise scales x 8 reps = 192;
  • readout circuits: 4;
  • total circuits: 196.

Optional extension after the default block:

  • add popcount-control states 0101, 0010, and 0111 at depths 8 and 14 only if the default block passes the live depth and cost gates.

QPU-Time Estimate

Expected IBM-reported QPU time for the default block: 5-12 minutes, depending on folded circuit depths.

Budget ceiling for default block: 15 IBM-reported QPU minutes.

Optional extension ceiling: additional 15 IBM-reported QPU minutes.

Abort before submission if folded circuits exceed the ceiling or if the remaining allocation cannot cover the block plus a 25 % safety margin.

Live Readiness Gates

Before submission:

  • confirm selected backend is Heron-class, account-visible, and operational;
  • generate unfolded and folded circuits from committed code only;
  • live-transpile every folded circuit;
  • reject if max depth at noise scale 5 exceeds the unscaled depth by more than the preregistered folding expectation plus 25 % overhead;
  • reject if live two-qubit gate count makes the QPU-time estimate exceed the budget ceiling;
  • record backend name, calibration timestamp, folding rule, depth summary, two-qubit gate summary, circuit count, shot count, and estimated QPU minutes;
  • get explicit approval immediately before submission.

Analysis Plan

Primary witness:

  • parity survival and parity leakage versus explicit noise scale.

Primary extrapolation:

  • fit log survival or leakage trend versus noise scale for each state/depth;
  • compare ordinary extrapolation against symmetry-decay guided extrapolation;
  • report calibration coefficients only for the sampled backend/layout/window.

Promoted summaries:

  • per-depth witness stability;
  • fit quality by state and sector;
  • extrapolated observable shift with confidence interval;
  • failure modes where folding destroys signal or fit quality.

Readout handling:

  • apply exact-state parity readout correction where the four readout states support it;
  • do not claim full confusion-matrix mitigation from four-state readout calibration.

Falsification Rules

The GUESS witness claim is rejected or downgraded if:

  • parity survival is not monotone or fit quality is poor across noise scales;
  • folded circuits introduce layout/transpilation artefacts larger than the witness trend;
  • even and odd sectors require incompatible witness models;
  • readout correction changes the sign or removes the extrapolation signal;
  • the fitted coefficients are unstable across depths.

If the result is negative, report it as a boundary on parity leakage as a GUESS witness for this circuit/backend family.

Output Artefacts

Expected paths after approved execution:

  • data/phase3_guess_dla/phase3_guess_<backend>_<timestamp>.json;
  • data/phase3_guess_dla/phase3_guess_summary_<date>.json;
  • data/phase3_guess_dla/phase3_guess_fit_rows_<date>.csv;
  • data/phase3_guess_dla/phase3_guess_extrapolation_rows_<date>.csv;
  • docs/campaigns/phase3_guess_dla_manifest_<date>.md.

Each artefact must include backend, folding rule, circuit metadata, raw counts, SHA256 hashes, depth/gate summaries, fit diagnostics, and reproduction commands.

Submission Boundary

This preregistration is complete. QPU execution remains blocked until backend selection, folded-circuit readiness artefacts, budget confirmation, and explicit approval are completed in a separate task.