Room_Temperature_Superconductor

This is the fourteenth paper (an applications paper) of the Light-Speed Critical FieldTheory (LS-CFT) Complete Series, dealing with the problem of room-temperature superconductivity. Positioning (honest boundary): room-temperature superconductivity isan unsolved scientific problem — this paper does not claim to solve it; the theoretical contribution of Light-Speed Critical Field Theory (LS-CFT) consists of three testable outputs: (1)mechanism criteria (the rescaling argument + the three-layer distinction of the phononceiling), (2) a material-system prediction (the B–C–N light-element layered doping system), and (3) a low-pressure fabrication roadmap (an operable parameter window +stopping discipline). Core derivation: the McMillan/Eliashberg phonon mechanism saturatesat strong coupling for B–C–N parameters (ΘD ≈ 1500 K , µ∗ = 0 .1) — the mathematicalextrapolation limit λ → ∞ gives Tmaxc = 341 K, whereas realistic phonon coupling (lightelement λph ≤ 0.6) reaches only ∼ 28 K (experimental anchor: MgB2 , λ ≈ 0.8 → 39 K ,the highest conventional phonon superconductor) — a room-temperature Tc throughthe phonon mechanism would require the unconventional strength λ ≥ 3, unreachable by light-element phonon physics; hence room temperature (if achievableat all) must come from rescaling: unconventional pairing channels enter the pairing formula Tgeoc ∼ Λgeo e −1/λgeo with the electronic scale Λgeo ∼ EF /kB ∼ 103–104 K (not theDebye scale) — λgeo ≥ 0.3 already reaches the room-temperature level . Definition of thecriterion line: Tc > 50 K = surpassing the measured conventional ceiling of MgB2 at 39 K(the layer-(3) criterion line; the 341 K mathematical extrapolation is irrelevant to the criterion). The geometric contribution of Light-Speed Critical Field Theory (LS-CFT) to thischannel: the internal-space Z3 three-channel structure yields a pairing-symmetry predictionand mechanism-discrimination criteria (isotope-effect exponent α ≈ 0 vs phonon α = 0 .5;weak vs strong pressure dependence — the mechanism can be fixed only when the twocriteria agree crosswise). Material system: the h-BCN layered doping system — Cu(111)substrate Moiré-superlattice matching (mismatch 2 .0–3.7%, residual strain 1–3% falls withinthe tuning window), the B–N domain period calibrated empirically via nucleation–growthdynamics, and a five-step, fully low-pressure, iteratively refinable process . Honest boundary: the existence of the geometric channel is an assumption (Tier II), while its criteria (isotope/pressure/symmetry)are falsifiable predictions (Tier I)—if the criterion experimentsexclude the geometric channel, the room-temperature roadmap of this paper is falsified —the same standard of honesty as for all predictions of the series .