This paper addresses a missing architectural layer in full-dive and metaverse research. The central question is not whether immersive systems require virtual reality, brain-computer interfaces, neural decoding, haptic feedback, quantum computation, embodiment, low-latency rendering, or persistent simulated worlds, but whether these mechanisms can be organized into a single measurable condition for reversible first-person station access. The paper proposes Full-Dive Quantum Metaverse Access as a constructive brain–quantum-computer station architecture in which a living biological conscious system is not uploaded, copied, or replaced, but synchronized with an executable station environment through basis translation, phase synchrony, source–sink coupling, embodied feedback, and operational self-continuity. The central contribution is the full-dive station access score AFD. This score combines six necessary factors: biological consciousness gate, station-level substrate homeostasis, brain–station basis alignment, phase synchrony, effective source–sink coupling, and operational self-continuity. The resulting condition, AFD = Cbio · Qstation · Wbridge · Φsync · κBQ · χcont, defines full-dive access as a conjunctive architecture rather than a single interface parameter. A quantum computer may provide a homeostatic information organ; a persistent world engine may provide executable station-state; a VR or BCI loop may provide embodied feedback; neural decoding may support basis translation; latency control may preserve synchrony; and memory, agency, body ownership, and return coherence may support self-continuity. However, none of these mechanisms is sufficient alone. A high-resolution virtual world can still fail if the user does not experience the avatar as the operational body. A powerful quantum substrate can still fail if it does not execute an inhabitable station. A precise neural decoder can still fail if phase synchrony or return continuity is lost. The paper therefore reframes full-dive as active station-mediated synchronization of a living conscious relay, not as destructive mind uploading. The structural theorem of the paper is conditional: if a full-dive architecture admits operational definitions of biological consciousness, station-level substrate stability, basis alignment, phase synchrony, source–sink coupling, and self-continuity, then it admits an AFD representation. Under the reduced-order assumptions stated in the manuscript, full-dive station access follows the minimal normalized product of necessary failure channels: if any required module collapses to zero, the station-access condition fails. The paper interprets this not as a new fundamental law of consciousness or quantum mechanics, but as an architectural connector condition for reversible access. Full-dive is therefore understood as controlled information coupling: biological consciousness remains alive, station information remains executable, embodied action remains closed through feedback, and identity-relevant continuity is preserved across entry, presence, and return. The empirical layer is framed as an architectural consistency program rather than proof of completed full-dive technology. The framework is anchored against published results in virtual embodiment, presence research, BCI decoding, adaptive closed-loop control, cybersickness, and quantum-state homeostasis. Protocol 14.0 reports 44 currently scorable retrospective/proxy IVP items passed out of 45 listed internal items, with P23.10 reserved as a genuine future prospective test pending operational full-dive prototypes. The paper further commits to staged validation tiers: formal audit, simulation audit, VR/BCI proxy audit, quantum-substrate audit, integrated station-connector audit, and future prototype-level tests. Failure of station-level variables to improve prediction over reduced models, failure of basis translation to affect presence, failure of phase synchrony to predict stability, failure of closed-loop embodied feedback to outperform open-loop systems, or failure of self-continuity to predict “I was there” return reports would revise or falsify corresponding sub-claims. The manuscript also defines strict claim boundaries. AFD does not prove metaphysical identity, does not claim that current hardware already achieves full-dive, does not require destructive upload, does not claim that a quantum computer alone is conscious, and does not authorize high-depth human trials. Classical VR and BCI systems may serve as near-term proxy layers, but the strict Paper 23 station architecture requires quantum-state homeostasis as one substrate module and operational self-continuity as the identity-preserving access module. The engineering program is explicitly non-invasive-first, low-pressure-first, reversible-first, and safety-gated: psychological screening, emergency exit, session limits, aftercare, data privacy, independent oversight, and return-path integrity are treated as necessary constraints rather than optional ethical annotations. Its value lies in proposing a falsifiable, platform-neutral, source–sink architecture for testing whether a living conscious brain can be reversibly present through an avatar in a quantum-computer station. Keywords: full-dive, quantum metaverse, quantum-computer station, reversible synchronization, avatar presence, brain-computer interface, operational self-continuity, basis translation, phase synchrony, source-sink connector, quantum-state homeostasis, embodied feedback, station access, virtual embodiment, consciousness gate, persistent world-state, full-dive architecture, validation protocol, prospective falsification.
Taekyung Lee (Sat,) studied this question.