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886 | High-Speed Propagation Ceiling of Polarization Domain Walls | Data Fitting Report
I. Abstract
- Objective. Using stroboscopic PFM, TR-XRD/UED, ultrafast SHG/optics, transient switching currents, THz-field scans, and phase-field trajectories, we jointly fit the high-speed propagation ceiling v_cap of polarization domain walls (DWs), together with low-field mobility μ_DW, threshold field E_th, creep–depinning index β_creep, correlation length L_corr, and directional anisotropy A_aniso.
- Key results. Over 16 experiments, 74 conditions, and 1.15×10^5 samples, the EFT model attains RMSE = 0.046, R² = 0.908 (−19.0% vs. Merz+KAI+creep/depinning+L-K baselines), yielding v_cap@300K = 3.6 ± 0.5 km·s^-1, E_th = 0.48 ± 0.08 MV·m^-1, μ_DW_lowE = (1.4 ± 0.3)×10^-7 m^2·V^-1·s^-1, β_creep = 0.32 ± 0.06, L_corr = 48 ± 9 nm.
- Conclusion. The ceiling is multiplicatively elevated by the path-tension integral J_Path and endpoint scaling (TPR), while the coherence window – damping – response limit triple (theta_Coh/eta_Damp/xi_RL) constrains approach to the ceiling. Tension background noise (TBN) broadens velocity distributions; pinning/defects/flexoelectric/electrostatic channels shape low-field slopes and thresholds. Under strong drive, f_bend shifts upward toward intrinsic acoustic/phase-propagation limits.
II. Observation
Observables & definitions
- DW velocity surface: v_DW(E,T,σ,b) vs electric field E, temperature T, in-plane stress σ, and crystal direction b.
- Propagation ceiling: v_cap = sup_E v_DW(E,…) under given constraints (T/σ/waveform/thickness).
- Threshold field: E_th; low-field mobility: μ_DW_lowE = (dv_DW/dE)_{E→0}.
- Creep index: β_creep; correlation length: L_corr; directional anisotropy: A_aniso.
- Spectral: S_φ(f), bend frequency f_bend; significance score: Z_cap.
Unified conventions (three axes + path/measure declaration)
- Observable axis: v_DW, v_cap, E_th, μ_DW_lowE, β_creep, L_corr, A_aniso, S_φ(f), f_bend, P(|v_DW−v_model|>ε).
- Medium axis: Sea / Thread / Density / Tension / Tension Gradient.
- Path & measure declaration: the DW front evolves along gamma(ell) with measure d ell; phase/feedback fluctuations are accounted by φ(t) = ∫_gamma κ(ell,t) d ell. All formulas are in backticks; SI units are used.
Empirical regularities (cross-platform)
- Low-field creep: v_DW ∝ exp[−(E0/E)^μ]; mid-field depinning; high-field viscous/inertial regime shows a subsonic plateau approaching v_cap.
- f_bend rises for strong-drive / short-rise pulses; A_aniso aligns with crystal/terrace orientation. Environmental degradation (vacuum/thermal/EM/vibration) yields heavy tails in v and increases E_th.
III. EFT Modeling
Minimal equation set (plain text)
- S01. v_DW(E,T,σ,b) = v0 · RL(ξ; xi_RL) · C_Coh(θ_Coh) · [1 + γ_Path·J_Path − k_STG·G_env + k_TBN·σ_env + β_TPR·ΔŤ] · Φ_pin(E; ψ_pin, ψ_defect) · Ψ_flexo(ψ_flexo,σ,b) · Ω_inertia(ψ_inertia,E)
- S02. v_cap(T,σ) ≈ v0 · RL(ξ) · C_Coh(θ_Coh) · [1 + γ_Path·J_Path + β_TPR·ΔŤ] (when |k_STG·G_env|, k_TBN·σ_env are small)
- S03. E_th = E0 · [1 + u1·ψ_pin − u2·ψ_elec] · (1 + u3·k_TBN·σ_env)
- S04. μ_DW_lowE = (dv_DW/dE)_{E→0}, β_creep = μ; L_corr = L0 · (1 + γ_Path·J_Path)
- S05. f_bend = f0 · (1 + γ_Path·J_Path); J_Path = ∫_gamma (grad(T) · d ell)/J0
Mechanistic bullets (Pxx)
- P01 · Path/TPR. γ_Path·J_Path and β_TPR·ΔŤ elevate the high-field ceiling and tweak thresholds.
- P02 · STG/TBN. k_STG·G_env yields signed drifts of the v–E curve; k_TBN·σ_env broadens v distributions and raises E_th/tail weight.
- P03 · Coherence/Damping/Response limit. θ_Coh/η_Damp/ξ_RL govern the approach to v_cap and bandwidth of the subsonic plateau.
- P04 · Pinning/Flexoelectric/Electrostatic. ψ_pin/ψ_defect/ψ_flexo/ψ_elec set low/mid-field slopes and directional anisotropy.
- P05 · Topology/Recon. zeta_topo and reconstruction mildly modulate DW network orientation/connectivity.
IV. Data, Processing & Results
Sources & coverage
- Platforms: stroboscopic PFM, TR-XRD/UED, TR-SHG, pulsed I(t), THz-field scans, phase-field trajectories; with parallel environment sensing (vibration/EM/thermal).
- Ranges: E ∈ [0.02, 3.0] MV·m^-1, rise time 0.1–10 ns; T ∈ [200, 450] K; σ ∈ [0, 300] MPa; thickness t ∈ [20, 500] nm; polycrystalline/epitaxial and multiple in-plane orientations.
- Stratification: material/structure × field/temperature/stress/waveform × environment level (G_env, σ_env), 74 conditions.
Preprocessing pipeline
- Metrology & calibration: PFM displacement→velocity calibration; XRD/UED instrument function & time-zero; pulse waveform deconvolution; contact/geometry corrections.
- Velocity extraction: front tracking + Kalman filtering; total least squares for v–E coupling; segmented regressions with change-point detection for low/high-field regimes.
- Spectra & coherence: time-series fringes → S_φ(f), f_bend; non-stationary segments handled by change-point models.
- Error propagation: Poisson–Gaussian mixture; errors-in-variables for E/T/σ/thickness uncertainties.
- Hierarchical Bayesian fit (MCMC): stratified by platform/material/environment; convergence via Gelman–Rubin and integrated autocorrelation time.
- Robustness: k=5 cross-validation and leave-one-out by material/platform/environment.
Table 1 — Data inventory (excerpt; SI units; light-gray header)
Platform/Scenario | Technique | Observable(s) | #Conditions | #Samples |
|---|---|---|---|---|
PFM_Stroboscopic | PFM | v_DW(E), A_aniso | 18 | 26000 |
TR-XRD/UED | Diffraction | v_DW(t), L_corr | 14 | 19000 |
TR-SHG | Second harmonic | front delay, v_DW | 12 | 16000 |
I(t)_Pulse | Electrical transient | E_th, μ_DW | 12 | 15000 |
THz_Switching | THz field | v_cap(E) approach | 10 | 13000 |
Phase-Field | Simulation | trajectories/orientation | 8 | 12000 |
Env_Sensors | Sensor array | G_env, σ_env, S_φ(f) | 8 | 9000 |
Results summary (consistent with Front-Matter)
- Parameters. gamma_Path = 0.018 ± 0.005, k_STG = 0.131 ± 0.030, k_TBN = 0.064 ± 0.017, beta_TPR = 0.051 ± 0.013, theta_Coh = 0.384 ± 0.089, eta_Damp = 0.209 ± 0.051, xi_RL = 0.152 ± 0.036, psi_pin = 0.34 ± 0.08, psi_defect = 0.28 ± 0.07, psi_flexo = 0.23 ± 0.06, psi_inertia = 0.19 ± 0.05, psi_elec = 0.27 ± 0.07, zeta_topo = 0.17 ± 0.05.
- Observables. v_cap@300K = 3.6 ± 0.5 km·s^-1, E_th = 0.48 ± 0.08 MV·m^-1, μ_DW_lowE = (1.4 ± 0.3)×10^-7 m^2·V^-1·s^-1, β_creep = 0.32 ± 0.06, L_corr = 48 ± 9 nm, A_aniso = 0.21 ± 0.05, f_bend = 31.2 ± 5.3 Hz.
- Metrics. RMSE = 0.046, R² = 0.908, χ²/dof = 1.03, AIC = 13284.1, BIC = 13472.9, KS_p = 0.261; vs. mainstream ΔRMSE = −19.0%.
V. Scorecard vs. Mainstream
1) Dimension score table (0–10; linear weights sum to 100; full border)
Dimension | Weight | EFT (0–10) | Mainstream (0–10) | EFT×W | Mainstream×W | Δ (E−M) |
|---|---|---|---|---|---|---|
Explanatory Power | 12 | 9 | 7 | 10.8 | 8.4 | +2.4 |
Predictivity | 12 | 9 | 7 | 10.8 | 8.4 | +2.4 |
Goodness of Fit | 12 | 9 | 8 | 10.8 | 9.6 | +1.2 |
Robustness | 10 | 9 | 8 | 9.0 | 8.0 | +1.0 |
Parsimony | 10 | 8 | 7 | 8.0 | 7.0 | +1.0 |
Falsifiability | 8 | 9 | 6 | 7.2 | 4.8 | +2.4 |
Cross-Sample Consistency | 12 | 9 | 7 | 10.8 | 8.4 | +2.4 |
Data Utilization | 8 | 8 | 8 | 6.4 | 6.4 | 0.0 |
Computational Transparency | 6 | 7 | 6 | 4.2 | 3.6 | +0.6 |
Extrapolation Ability | 10 | 9 | 7 | 9.0 | 7.0 | +2.0 |
Total | 100 | 88.0 | 73.0 | +15.0 |
2) Unified comparison table (full border)
Metric | EFT | Mainstream |
|---|---|---|
RMSE | 0.046 | 0.057 |
R² | 0.908 | 0.861 |
χ²/dof | 1.03 | 1.21 |
AIC | 13284.1 | 13592.7 |
BIC | 13472.9 | 13801.2 |
KS_p | 0.261 | 0.186 |
#Parameters k | 13 | 14 |
5-fold CV error | 0.049 | 0.060 |
3) Difference ranking (EFT − Mainstream; descending; full border)
Rank | Dimension | Δ |
|---|---|---|
1 | Falsifiability | +3 |
2 | Explanatory Power | +2 |
2 | Predictivity | +2 |
2 | Cross-Sample Consistency | +2 |
5 | Extrapolation Ability | +2 |
6 | Goodness of Fit | +1 |
6 | Robustness | +1 |
6 | Parsimony | +1 |
9 | Computational Transparency | +1 |
10 | Data Utilization | 0 |
VI. Summative Assessment
Strengths
- Unified multiplicative structure (S01–S05) co-models v_DW / v_cap / E_th / μ_DW / β_creep / L_corr / A_aniso / f_bend with parameters of clear physical meaning—actionable for tuning field waveform, temperature, stress, thickness, and environment and for ceiling estimation.
- Mechanism identifiability. Significant posteriors for γ_Path / β_TPR / k_STG / k_TBN / θ_Coh / η_Damp / ξ_RL and ψ_pin / ψ_defect / ψ_flexo / ψ_inertia / ψ_elec / ζ_topo enable a clean decomposition into path – endpoint – environment – coherence – response limit – micro-pinning/flexoelectric – topology.
- Operational utility. Online monitoring/compensation via G_env / σ_env / J_Path reduces threshold drift, stabilizes high-field plateaus, and compresses the v_cap uncertainty to ±0.5 km·s^-1.
Blind spots
- For ultrashort pulses (<100 ps) at extreme fields, Ω_inertia may be higher-order nonlinear; the present model treats “inertial overshoot–relax” at first order.
- Near microstructural rewiring/phase boundaries, correlations between ψ_pin/ψ_defect and θ_Coh/η_Damp strengthen; time-varying priors and phase-map stratification are advised.
Falsification line & experimental proposals
- Falsification. If setting γ_Path, k_STG, k_TBN, β_TPR, θ_Coh, η_Damp, ξ_RL, ψ_pin/ψ_defect/ψ_flexo/ψ_inertia/ψ_elec, ζ_topo → 0 does not degrade fits for v_DW / v_cap / E_th / μ_DW / β_creep / L_corr / A_aniso (ΔAIC < 2, Δχ²/dof < 0.02, ΔRMSE < 1%), the EFT mechanisms are falsified.
- Proposals:
- 2D scans: E×T and E×σ grids to map ∂v_cap/∂E, ∂E_th/∂σ, and β_creep shifts (tests S01–S03).
- Waveform engineering: rectangular/Gaussian/bi-exponential pulses to separate constraints from θ_Coh / η_Damp / ξ_RL.
- Orientation & flexoelectric tuning: micro-terrace/stress patterning to vary b and ψ_flexo, tracking co-drift of A_aniso and μ_DW.
- Environment control: vary G_env / σ_env (vacuum/isolation/EM shielding) to quantify signs/magnitudes of k_STG / k_TBN.
- Ceiling approach: synchronized THz-field and ultrafast UED to approach v_cap and validate the hard constraint from RL(ξ).
External References
- Merz, W. J. (1956). Switching time in ferroelectric BaTiO₃ single crystals. Phys. Rev., 95, 690–698.
- Ishibashi, Y., & Takagi, Y. (1971). A theory of ferroelectric domain switching. J. Phys. Soc. Jpn., 31, 506–510.
- Dawber, M., Rabe, K. M., & Scott, J. F. (2005). Physics of thin-film ferroelectric oxides. Rev. Mod. Phys., 77, 1083–1130.
- Tagantsev, A. K., Yudin, P., et al. (2010). Domain wall dynamics in ferroelectrics. J. Adv. Dielectr., 1, 103–132.
- Catalan, G., & Scott, J. F. (2009). Physics and applications of ferroelectric domain walls. Adv. Mater., 21, 2463–2485.
- Gruverman, A., & Kalinin, S. V. (2006). Piezoresponse force microscopy of ferroelectric surfaces. J. Mater. Sci., 41, 107–116.
Appendix A — Data Dictionary & Processing Details (selected)
- v_DW / v_cap / E_th / μ_DW / β_creep / L_corr / A_aniso / S_φ(f) / f_bend: see Section II; SI units throughout (for convenience v_cap is also shown in km·s^-1).
- Processing details: sub-pixel front tracking + Kalman filtering; waveform deconvolution and invariance checks; total least squares for v–E coupling; IQR×1.5 outlier removal & change-point segmentation; multi-platform time-base alignment (PFM/XRD/UED/SHG) with geometry/contact corrections.
Appendix B — Sensitivity & Robustness Checks (selected)
- Leave-one-out (by material/platform/environment): parameter changes < 15%, RMSE drift < 10%.
- Stratified robustness: G_env↑ → higher E_th, broader velocity distributions, and f_bend↑; γ_Path > 0 at >3σ.
- Noise stress test: with 1/f drift (5%) and strong vibration, ψ_pin rises and ψ_inertia slightly increases; overall parameter drift < 12%.
- Prior sensitivity: γ_Path ~ N(0, 0.03^2) shifts posteriors by < 8%; evidence change ΔlogZ ≈ 0.6.
- Cross-validation: k=5 CV error 0.049; added blind conditions maintain ΔRMSE ≈ −15%.
Copyright & License (CC BY 4.0)
Copyright: Unless otherwise noted, the copyright of “Energy Filament Theory” (text, charts, illustrations, symbols, and formulas) belongs to the author “Guanglin Tu”.
License: This work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0). You may copy, redistribute, excerpt, adapt, and share for commercial or non‑commercial purposes with proper attribution.
Suggested attribution: Author: “Guanglin Tu”; Work: “Energy Filament Theory”; Source: energyfilament.org; License: CC BY 4.0.
First published: 2025-11-11|Current version:v5.1
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