Pressure-Locked Apical-Anion Resonance in Multilayer Hg Cuprates: An AI-Guided Route Toward Ambient-Pressure Room-Temperature Superconductivity

Ambient-pressure room-temperature superconductivity remains one of the highest-valueunsolved problems in condensed-matter physics. The contemporary materials landscapepoints in two conflicting directions. On one side, machine-learning-accelerated searches havebecome scientifically serious: ambient-pressure conventional hydride candidates with predictedtransition temperatures above 80 K have been reported, and end-to-end AI-acceleratedworkflows have already delivered experimentally confirmed new superconductors. On theother side, large-scale analyses of conventional superconductors at ambient pressure indicatethat room-temperature conventional superconductivity is unlikely in practice because thesame trends that raise the pairing scale also drive systems toward instability. Simultaneously,the Hg-based cuprates remain the strongest ambient-pressure platform presently known:Hg-1223 defines the ambient cuprate record, fluorination compresses the in-plane lattice andraises the pressure-enhanced ceiling, and pressure-quench protocols have now produced aretained ambient-pressure state at 151 K without maintaining pressure.Motivated by these facts, this paper argues that the most credible route to room-temperature operation at ambient pressure is not a purely conventional hydride, but ametastable multilayer cuprate in which apical-anion chemistry, interlayer inequivalence, andpressure-locked local structure cooperate to amplify both the pairing scale and the phasestiffness. The primary target family is fluorine-stabilized HgBa2Ca2Cu3O8+δ−xFx processedthrough a pressure-quench-and-lock sequence and then retained either by bulk encapsulationor by epitaxial strain. The central physical claim is that shortening the in-plane latticeparameter and reshaping the apical environment can raise the superexchange-driven pairingscale, while a pressure-locked charge-transfer imbalance between inner and outer CuO2planes can create an interlayer shape-resonance channel that elevates the phase coherencetemperature beyond the current retained ambient record.We formulate an effective model, define a synthesis program, identify quantitative controlvariables, and list decisive transport, spectroscopic, structural, isotope, and relaxationsignatures. The manuscript therefore functions as a falsifiable target paper: if the predictedstructural lock-in, interlayer imbalance, and gap hierarchy are not observed together, thenthe proposed mechanism is wrong.