Deterministic Limit for Quantum Decoherence: Deriving the Critical Environmental Noise Radius via Phase Coherence

The prediction of wavefunction collapse and quantum decoherence in solid-state quantum processors, such as superconducting transmon lattices, relies heavily on the stochastic Lindblad master equation and empirical T1 and T2 relaxation times. While these thermodynamic and statistical frameworks effectively estimate the aggregate probability of quantum error over time, they fail to deterministically define the exact spatial boundary where localized environmental coupling triggers an irreversible collapse of the superposition state. This paper introduces a strict continuum framework for quantum information science. By modeling the topological quantum state as a dynamic kinematic balance between the spatial capacity for phase entanglement (phase coherence) and the localized rate of classical measurement (environmental coupling), we derive a universal critical decoherence radius (Rcollapse). We demonstrate that wavefunction collapse is not a probabilistic decay over time, but an exact deterministic limit where localized environmental perturbation strictly overpowers the advective phase-distributing capacity of the surrounding topological geometry. We propose a blueprint for Absolute Topological Qubit Scaling to guarantee infinite coherence, bypassing massive software-based error-correction overheads.