A Josephson–SQUID Barrier-Clock Diagnostic for the Residual Clock–Energy Framework
Byoungwoo Lee
Abstract
This record contains Version v0.6r2 of *A Josephson–SQUID Barrier-Clock Diagnostic for the Residual Clock–Energy Framework*. This version is a synthetic-noise sensitivity and application-readiness update to the earlier Josephson–SQUID executable diagnostic line. This manuscript is not an empirical detection paper, not a proposal for a new Josephson law, and not a replacement for standard Josephson/SQUID physics. Instead, it develops a residual phase-clock covariance diagnostic built on standard Josephson/SQUID baseline physics, RCSJ-style phase dynamics, tunneling-opacity language, and mock-data sensitivity calibration. The diagnostic is organized around the flux-control parameter $$u=\frac{\Phi_{\rm ext}}{\Phi_0},$$ and the observable vector $$u\longmapsto\left(I_c(u),\Gamma_\phi(u),\frac{\delta\nu_{\rm osc}}{\nu_{\rm osc}}(u),S_{\phi\phi}(\omega;u)\right).$$ Here \(I_c\) is the critical current, \(\Gamma_\phi\) is a phase-dephasing rate, \(\delta\nu_{\rm osc}/\nu_{\rm osc}\) is a fractional oscillator or clock-frequency shift, and \(S_{\phi\phi}\) is a phase-noise spectral density. The Residual Clock–Energy input is represented by the residual phase-tension one-form $$\alpha=d\Phi-A,$$ which is compared with the gauge-invariant superconducting phase difference $$\phi=\varphi_1-\varphi_2-\frac{2\pi}{\Phi_0}\int_1^2 A\cdot d\ell .$$ The earlier v0.5r2 version introduced a positive-control toy residual drive, $$\mathcal R_J(u)=r_0\sin^2(\pi u),$$ and used it as a morphology target for baseline-subtracted Josephson/SQUID observables. Version v0.6r2 extends this line by injecting synthetic noise and nuisance morphologies into mock observations, $$y_{k,i}^{\rm obs}(A)=A\beta_k g_i+n_{k,i}+h_{k,i},$$ where \(g_i\) is the centered residual morphology, \(n_{k,i}\) is a synthetic noise term, and \(h_{k,i}\) is a nuisance contribution. The central sensitivity outputs are the detection probability, $$P_{\rm det}(A)=\frac{1}{N_{\rm MC}}\sum_{m=1}^{N_{\rm MC}}\mathbf 1[\text{trial }m\text{ passes}],$$ the minimum detectable amplitude, $$A_{\min}=\inf\{A:P_{\rm det}(A)\ge0.95\},$$ and the false-positive rate, $$P_{\rm FP}=P_{\rm det}(0).$$ Version v0.6r2 includes: 1. synthetic observation models for residual and nuisance channels;2. white-noise, high-noise, correlated-drift, heating-mimic, and mixed-nuisance scenarios;3. morphology-score and signal-to-noise recovery criteria;4. a multi-channel admission rule requiring at least two non-current channels to pass;5. matched-control subtraction for heating-like nuisance;6. false-positive and detection-probability curves;7. sensitivity tables and CSV outputs;8. an application-readiness ladder from toy positive control to device-screening protocol;9. laboratory deployment requirements for a future calibrated experiment;10. device-facing output interpretation tables. A key outcome of the synthetic study is that heating-like nuisance can overlap strongly with the residual morphology and can therefore create false-positive hazards if not controlled. The v0.6r2 update explicitly treats this issue by introducing matched-control subtraction and by distinguishing raw nuisance-contaminated recovery from controlled recovery. The application-readiness ladder used in this version is: - L0: toy positive-control morphology;- L1: synthetic-noise recovery and false-positive stress test;- L2: calibrated synthetic noise using measured device noise floors;- L3: laboratory pilot with real Josephson/SQUID data;- L4: device-screening protocol for phase-noise and barrier-quality diagnostics. The current v0.6r2 manuscript is positioned at L1. It is therefore a synthetic sensitivity and application-readiness note, not a calibrated laboratory demonstration. The included files provide the PDF manuscript, LaTeX source, figure-generation script, synthetic sensitivity summary CSV, detection-curve CSV, matched-control example CSV, simulation metadata JSON, and a source bundle for reproducibility. This work is a companion device-facing diagnostic note following the broader protocol record *Prediction and Discriminating Experiments for the Residual Clock–Energy Framework*, Version v0.4r1, DOI: 10.5281/zenodo.19846816.