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SPDX-License-Identifier: AGPL-3.0-or-later

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© Concepts 1996–2026 Miroslav Šotek. All rights reserved.

© Code 2020–2026 Miroslav Šotek. All rights reserved.

ORCID: 0009-0009-3560-0851

Contact: www.anulum.li | protoscience@anulum.li

scpn-quantum-control — Results

Results

Kuramoto-XY simulator, compiler, and hardware-evidence ledger for heterogeneous-frequency coupled oscillators.

For source classification and campaign provenance, see the dated Hardware Status Ledger. This page is a gallery and technical summary; the ledger is the canonical index for whether a result is theoretical, simulated, hardware-measured, mitigated, or noise-limited.

Status Snapshot — 2026-05-05

Area Public status
Promoted hardware campaigns April 2026 ibm_kingston Phase 1 DLA parity raw-count dataset; May 2026 ibm_kingston Phase 2 A+G n=4 replication and B-C n=6,8 mixed scaling raw-count datasets; legacy artefact-backed ibm_fez baseline rows.
Simulator-only families BKT scaling, OTOC, Floquet DTC, MBL/eigenstate scans, FIM, and classical wall-time baselines unless a hardware artefact is named.
Pending / quarantined IBM batches V2, frontier, queued-job, placeholder, aggregate-only IBM outputs, Phase 2 D-E larger scaling, Phase 2 F/GUESS mitigation, and multi-device replication are not promoted here until raw counts, retrieval manifests, and analysis scripts are reviewed and committed.
Canonical status source Hardware Status Ledger.

Key Findings

# Finding Measured Value Source
1 DLA parity raw-count reproduction Phase 1: 342 circuits, peak asymmetry +17.48% at depth 6; Phase 2 reduced A+G: 612 circuits, Fisher p=3.77e-20; Phase 2 B-C: mixed n=6,8 scaling data/phase1_dla_parity/, data/phase2_dla_parity/, data/phase2_scaling_bc/, scripts/run_dla_parity_suite.py, scripts/analyse_phase2_dla_parity.py, scripts/analyse_phase2_scaling_bc.py
2 Bell inequality row CHSH S=2.165, S=2.188 (>8σ) Legacy ibm_fez artefact row
3 QKD row QBER 5.5% < BB84 threshold (11%) Legacy ibm_fez artefact row
4 State preparation row 94.6% (∣0⟩), 89.8% (∣1⟩) Legacy ibm_fez artefact row
5 ZNE row Range 0.259–0.272 across folds 1–9 Legacy ibm_fez artefact row
6 Knm ansatz row 2.36 bits vs TwoLocal 3.46 Legacy ibm_fez artefact row
7 16-qubit UPDE row 13/16 qubits ∣⟨Z⟩∣>0.3 Legacy ibm_fez artefact row
8 Schmidt gap transition K=3.44 (n=8) Exact simulation
9 Critical coupling extrapolation K_c(∞): BKT≈2.20, power≈2.94 Finite-size scaling
10 DTC survives disorder 15/15 drive amplitudes Floquet simulation
11 Scrambling peak 4× faster at K=4 vs K=1 OTOC simulation
12 Trotter error row dt=0.1 vs dt=0.05 flips Q1 sign Legacy ibm_fez artefact row
13 Non-ergodic regime (not deep MBL) Poisson level spacing + 25-33% sub-thermal eigenstate S Level spacing + eigenstate scan
14 BKT universality preserved CFT c=1.04 (n=8), gap R²>0.96 Kaggle computation (n=4-12)
15 Exact-simulation crossover n≈11.6, exact Hilbert-space only Classical baselines plus hardware-budget estimates; not broad advantage

Simulation Results

Entanglement Entropy and Schmidt Gap

Half-chain entanglement entropy and Schmidt gap across coupling strength for n=2,3,4,6,8 oscillators with Paper 27 heterogeneous frequencies.

Entanglement vs coupling

The Schmidt gap dip at K≈3.4 (n=8) marks the synchronisation transition. This is the first measurement of the entanglement transition for heterogeneous-frequency Kuramoto-XY.

High-Resolution Transition Zoom

Transition zoom

60-point resolution in the transition region (K=1–5). The n=8 Schmidt gap drops sharply at K=3.44 — the cleanest transition signature.

Krylov Complexity

Operator spreading measured via Lanczos coefficients \(b_n\) and peak Krylov complexity \(K_{max}(t) = \sum_n n|\phi_n(t)|^2\).

Krylov vs coupling

Mean Lanczos \(b\) grows linearly with coupling (operator growth rate scales with K). Peak complexity saturates at the Hilbert space dimension.

OTOC (Information Scrambling)

Out-of-time-order correlator \(F(t) = \text{Re}\langle W^\dagger(t) V^\dagger W(t) V\rangle\) at sub-critical (K=1) and super-critical (K=4) coupling.

OTOC time traces

Strong coupling scrambles 4× faster: \(t^* = 0.28\) (K=4) vs \(t^* = 1.17\) (K=1) at n=8.

Floquet Discrete Time Crystal

Periodically driven Kuramoto-XY: \(K(t) = K_0(1 + \delta\cos\Omega t)\) with heterogeneous natural frequencies \(\omega_i\).

Floquet DTC

All 15 drive amplitudes show subharmonic response above the DTC threshold. Heterogeneous frequencies do not destroy the discrete time crystal. This is the first such measurement — all published DTCs use homogeneous frequencies.

Finite-Size Scaling

Critical coupling \(K_c(N)\) extracted from spectral gap minimum across system sizes N=2,3,4,6.

Finite-size scaling

Two extrapolations to the thermodynamic limit: BKT ansatz \(K_c(\infty) \approx 2.20\), power-law \(K_c(\infty) \approx 2.94\).

Combined Transition Overview

Combined overview

Four probes of the synchronisation quantum phase transition: spectral gap, entanglement entropy, Krylov complexity, and Schmidt gap. All computed with Paper 27 heterogeneous frequencies.


IBM Hardware Results

Two campaigns on Heron r2 (156-qubit) processors:

  • ibm_fez — legacy March 2026 baseline artefacts. Values may be quoted only with their committed artefact path and should not be used as broad advantage or frontier validation.
  • ibm_kingston — April 2026 Phase 1 DLA-parity campaign, 342 circuits across 4 sub-phases. This is the promoted raw-count hardware dataset because the counts, job IDs, integrity checks, and reproduction harness are committed.

Phase 1 — DLA Parity Asymmetry (April 2026, ibm_kingston)

DLA parity leakage vs depth

DLA parity asymmetry vs depth

The XY Hamiltonian's dynamical Lie algebra splits as \(\mathfrak{su}(2^{n-1}) \oplus \mathfrak{su}(2^{n-1})\) under the parity operator \(P = \prod_i Z_i\). The SCPN simulator predicts the odd ("feedback") sub-block is more robust to depolarising noise than the even ("projection") sub-block by 4.5–9.6 % at moderate Trotter depths. The Phase 1 campaign on ibm_kingston reproduces this from committed raw counts:

Trotter depth Leak even Leak odd Asymmetry Welch \(p\) Reps
2 0.0806 0.0827 \(-2.5\%\) 0.45 (baseline) 12
4 0.0982 0.0862 \(+14.0\%\) \(1.4 \times 10^{-6}\) 21
6 0.1291 0.1099 \(+17.5\%\) \(6.6 \times 10^{-6}\) 21
8 0.1443 0.1284 \(+12.4\%\) \(8.9 \times 10^{-5}\) 21
10 0.1658 0.1495 \(+10.9\%\) \(6.7 \times 10^{-6}\) 21
14 0.1898 0.1797 \(+5.6\%\) 0.010 21
20 0.2295 0.2114 \(+8.6\%\) 0.0067 12
30 0.2771 0.2576 \(+7.6\%\) 0.0095 12
  • 7 of 8 depths are individually significant at Welch \(p < 0.05\).
  • Fisher's combined statistic: \(\chi^2_{16} = 123.4\), combined \(p \ll 10^{-16}\).
  • Mean asymmetry for depths \(\ge 4\): \((10.8 \pm 1.1)\,\%\) — consistent with and in the upper range of the apriori \(4.5\text{–}9.6\,\%\) classical simulator prediction.
  • Strongest signal: depth 6, \(+17.48\,\%\), \(5.4\sigma\).

Reproducible from the raw JSON in data/phase1_dla_parity/ via python scripts/analyse_phase1_dla_parity.py.

A 267-line short paper draft for Quantum Science and Technology / Physical Review Research is in paper/phase1_dla_parity/phase1_dla_parity_short_paper.md.

Phase 2 — Reduced A+G Replication (May 2026, ibm_kingston)

The reduced Phase 2 run repeated the n=4 DLA parity test with 30 reps per depth/sector at 4096 shots, plus a same-run readout baseline. Blocks B-F (n=6-12 scaling and GUESS calibration) were not submitted.

Phase 2 n=4 replication asymmetry

Trotter depth Leak even Leak odd Asymmetry Welch p
2 0.08370 0.08247 +1.49% 0.278
4 0.12009 0.11053 +8.65% 1.56e-08
6 0.15296 0.14659 +4.35% 1.94e-04
8 0.17339 0.16879 +2.72% 0.00352
10 0.19599 0.18761 +4.47% 9.64e-07
14 0.23883 0.22912 +4.24% 6.14e-06
20 0.28904 0.28035 +3.10% 2.59e-05
30 0.34557 0.34524 +0.10% 0.857
40 0.38906 0.38868 +0.10% 0.855
50 0.42153 0.42188 -0.08% 0.857
  • Fisher's combined statistic: chi2 140.671952, p 3.773718e-20.
  • Significant depths: 6/10 at Welch p < 0.05.
  • Readout baseline: 12/12 circuits complete at 8192 shots, with state retention from 95.0% to 99.2%.

Reproduce from raw counts via PYTHONDONTWRITEBYTECODE=1 /home/anulum/.local/bin/python scripts/analyse_phase2_dla_parity.py --verify-integrity.

Phase 2 — B-C Scaling Continuation (May 2026, ibm_kingston)

The B-C continuation tested only n=6 and n=8; blocks A, D, E, F, and G were skipped. The same-day A+G readout baseline remains the readout-control source.

Phase 2 B-C mixed scaling asymmetry

n Trotter depth Leak even Leak odd Asymmetry Welch p
6 4 0.20653 0.20592 +0.30% 0.757
6 8 0.27606 0.28678 -3.74% 8.37e-07
6 14 0.35409 0.35586 -0.50% 0.407
6 20 0.40681 0.41484 -1.94% 3.05e-04
8 4 0.26626 0.25768 +3.33% 8.35e-04
8 8 0.37186 0.36606 +1.58% 0.0231
8 14 0.44863 0.44276 +1.33% 0.0252
8 20 0.43387 0.43333 +0.12% 0.842
  • n=6: Fisher chi2 46.531552, p 1.883218e-07, 2/4 significant depths.
  • n=8: Fisher chi2 29.420107, p 2.675193e-04, 3/4 significant depths.
  • IBM-reported usage: 305 quantum seconds for job ibm-run-1f46ebd0da8912ff.

Interpretation: this is mixed scaling evidence. The n=8 middle-depth sign is positive, but n=6 has negative significant depths. It falsifies a simple monotone scaling story and must not be cited as broad scaling validation.

Reproduce from raw counts via PYTHONDONTWRITEBYTECODE=1 /home/anulum/.local/bin/python scripts/analyse_phase2_scaling_bc.py data/phase2_scaling_bc/phase2_scaling_bc_2026-05-05T124722Z.json --sha256 f9718c3789329dbaa96a1667f8a581e3d1774632b961a1760c044138ccab6550.

Phase 2 Publication Package

The release-ready Phase 2 manifest is docs/publication_phase2_package_2026-05-05.md. It indexes the promoted raw-count files, integrity hashes, job IDs, figure artefacts, reproduction commands, and claim boundaries.

The excitation-count confound control is preregistered in docs/ibm_popcount_control_manifest_2026-05-05.md. It has now been executed and promoted under data/phase2_popcount_control/. The control shows that the original middle-depth contrast survives, but same-popcount within-sector swaps are also significant and the popcount-3 odd arm generally leaks more than the popcount-2 even arm. The paper should therefore use the conservative wording parity-sector and excitation-number correlated leakage asymmetry, not DLA parity alone.

Phase 2 — Popcount-Control Follow-up (May 2026, ibm_kingston)

The popcount-control run tested the main excitation-count confound in the n=4 DLA parity protocol. It used 360 parity-leakage circuits and 5 readout circuits.

Comparison Fisher chi2 Fisher p Significant depths Interpretation
E0 0011 minus O0 0001 127.260593 2.186677e-21 4/6 Original contrast persists at middle depths but reverses at depth 20.
E0 0011 minus E1 0101 117.374982 2.059878e-19 5/6 Within-even same-popcount state spread is large.
O0 0001 minus O1 0010 90.150466 4.617056e-14 4/6 Within-odd same-popcount state spread is large.
E0 0011 minus O3 0111 139.164854 8.829457e-24 4/6 Higher-excitation odd state usually leaks more than E0, consistent with excitation-count contribution.

Jobs:

  • Main: ibm-run-7d468e2b1e44b406
  • Readout: ibm-run-b3424c38cfe03c86

Raw JSON SHA256:

f43cbd7e466a3267847b44a750aeba7801cbc52ef10e9808573ef7ed01ec3cf0

Reproduce:

PYTHONDONTWRITEBYTECODE=1 /home/anulum/.local/bin/python scripts/analyse_phase2_popcount_control.py --verify-integrity

Legacy ibm_fez Results (March 2026)

The ibm_fez rows below are retained as legacy hardware observations. They must be cited with artefact paths from results/ibm_hardware_2026-03-28/, results/march_2026/, or the hardware ledger, and they are not evidence for broad quantum advantage or any frontier claim.

Bell Test and QKD

Hardware: CHSH + QBER

  • (a) Per-qubit ⟨Z⟩ heatmap across 4-qubit circuits
  • (b) 8-qubit Z-expectations show Kuramoto coupling pattern
  • (c) QKD QBER: 5.5% (ZZ), 5.8% (XX) — below BB84 11% threshold
  • (d) CHSH: S=2.165 > 2 — classical limit violated on quantum hardware

Full Experiment Suite

Hardware analysis

  • (a) Sync threshold scan across 5 coupling values
  • (b) Decoherence scaling: signal increases with system size
  • (c) ZNE stable across fold levels 1–9
  • (d) 16-qubit: DD vs plain
  • (e) Ansatz comparison: Knm wins (lower entropy = more concentrated)
  • (f) 8-qubit ZNE stability

Quantitative Characterisation

Quantitative hardware

  • (a) Per-qubit readout errors: asymmetric 0→1 vs 1→0
  • (b) ZNE per-qubit stability across fold levels
  • (c) CHSH correlators with error bars (>8σ violation)

Correlator, Trotter, 16-Qubit, VQE

Complete analysis

  • (a) ZZ correlation matrix: CX layer creates expected anti-correlations
  • (b) Trotter order comparison: dt=0.05 vs dt=0.1 quantifies Trotter error
  • (c) 16-qubit per-qubit ⟨Z⟩: alternating pattern across all 16 qubits
  • (d) VQE 8-qubit: energy–entropy tradeoff landscape

Exact-Simulation Crossover Boundary

Quantum advantage crossover

The n≈11.6 crossover is a resource boundary for exact Hilbert-space simulation, anchored by completed ibm_fez scaling runs and committed classical baseline timings. It is not a broad quantum-advantage claim: Rust Kuramoto ODE baselines remain faster through n≤16, and the largest hardware runs are noise-limited.


Many-Body Localisation Diagnostic

Level spacing ratio \(\bar{r}\) distinguishes integrable/MBL (\(\bar{r} \approx 0.386\), Poisson) from chaotic/thermalising (\(\bar{r} \approx 0.530\), GOE) spectra.

MBL level spacing

Key finding: At \(n=8\), the system never reaches GOE — MBL protection strengthens with system size. The heterogeneous frequencies act as effective disorder preventing thermalisation. This is the physics behind identity persistence: the coupling topology is protected from thermal decoherence.

Cross-validation (eigenstate entanglement): Excited-state entropy is 30–40% below thermal (Page) expectation, confirming non-ergodicity. However, entropy grows with N (sub-volume, not area law), ruling out deep MBL. Correct label: non-ergodic regime — coupling topology protected from thermal scrambling.

Eigenstate entanglement

First application of level-spacing diagnostics (standard tool, Oganesyan & Huse 2007) to heterogeneous-frequency Kuramoto-XY.

BKT Universality Confirmation

Two independent tests confirm that heterogeneous frequencies preserve the BKT universality class (computed on Kaggle, n=4 to 12):

CFT central charge: Fitting \(S(l) = (c/3)\ln(l) + \text{const}\) at \(K \approx K_c\):

n c (measured) BKT prediction
6 0.951 1.000
8 1.039 1.000
10 1.214 1.000
12 1.305 1.000

\(c \approx 1\) at n=6,8 confirms BKT. Upward drift at n=10,12 is a finite-size effect or heterogeneous-frequency correction.

Spectral gap essential singularity: Fitting \(\Delta \sim \exp(-b/\sqrt{K - K_c})\):

n K_c b Verdict
4 2.83 2.60 0.975 BKT confirmed
6 3.86 2.21 0.970 BKT confirmed
8 3.60 2.27 0.969 BKT confirmed

R² > 0.96 at n=4,6,8 — the essential singularity is a definitive BKT signature. No prior measurement for heterogeneous-frequency Kuramoto-XY.


Rust Acceleration Benchmarks

Measured on Windows 11, Python 3.12, Rust release build. See Rust Engine for full API.

Function n Rust Reference Speedup
Hamiltonian construction 4 0.004 ms 20.9 ms (Qiskit) 5401×
Hamiltonian construction 8 0.4 ms 63 ms (Qiskit) 158×
OTOC (30 time points) 4 0.3 ms 74.7 ms (scipy) 264×
OTOC (30 time points) 6 48 ms 5.66 s (scipy) 118×
Lanczos (50 steps) 3 0.05 ms 1.3 ms (numpy) 27×
Lanczos (50 steps) 4 0.5 ms 4.8 ms (numpy) 10×