Experimental Evidence for Quantum Phase Dynamics: Non-Exponential Decoherence in Neutron Interferometry

This study presents a reanalysis of high-precision neutron interferometry data from the Institut Laue-Langevin (ILL), revealing a significant deviation from the traditionally expected exponential decoherence. The interference visibility exhibits a stretched-exponential decay, characterized by $V(t) = V_0 \exp[-(t/\tau_{\mathrm{coh}})^{1+\varepsilon}]$ with a measured $\varepsilon = 0.18 \pm 0.08$, in agreement with the theoretical prediction of $\varepsilon = 0.23 \pm 0.02$. These results provide the first experimental support for the Quantum Phase Interpretation (QPI), in which quantum systems evolve through dynamical phases rather than static states. The phase-based model achieves a substantially better fit than conventional collapse models, with a 3.9-fold improvement in $\chi^2$, and aligns closely with the theoretical framework of nonlinear phase diffusion. The study has significant implications for the foundations of quantum mechanics, offering new insights into decoherence mechanisms, the measurement problem, and the emergence of classicality from quantum phase dynamics. Proposed future experiments aim to test phase evolution across different quantum systems, including photons, neutrons, and quantum dots. Keywords: Quantum Phase, Neutron Interferometry, Decoherence, Non-Exponential Decay, Quantum Foundations, Phase Dynamics, Measurement Problem