Coherence-Driven Phase Transitions and Defect Dynamics in PdTe2 to PdTe Thin Films

This work develops a coherence-field interpretation of the large-area non-stoichiometric phase transition observed in PdTe2 thin films. The PdTe2-to-PdTe conversion is treated as a reorganization of coherence phase structure rather than a purely chemical or phonon-mediated process. Within this framework, phase-gradient stress acts as a primary dynamical driver of tellurium vacancy nucleation, intermediate heterostructure stabilization, and boundary formation. Vacancies are interpreted as coherence antisolitons that relieve accumulated phase stress. PdTe2/PdTe interfaces are modeled as coherence domain walls that localize stress and serve as active transduction regions. The work further identifies boundary-localized terahertz emission as a direct radiative decay channel of coherence gradients, derives a minimal electromagnetic coupling mechanism, and connects helicity dependence to interfacial phase chirality. Superconducting enhancement in PdTe films is reframed as coherence phase-locking facilitated by boundary pre-loading. A central prediction is that electronic effective mass reflects coherence stiffness rather than solely band curvature, leading to testable signatures in spatially resolved and strain-tunable ARPES measurements. The paper includes explicit derivations of phase-gradient stress transport, topological defect energetics, electromagnetic radiation coupling, and stiffness-linked inertial response, and proposes a set of falsifiable experimental protocols to distinguish coherence-mediated dynamics from conventional lattice and electronic models.