Resonant Tunneling and Resonant Excitation Transfer

Issues involved in the tunneling of deuterons in metal deuterides are considered in relation to experimental claims of anomalies in metal deuterides. From earlier studies, screening is thought to be similar to the case of molecular D2. Resonant tunneling has been advocated in the literature as a possible mechanism to achieve tunneling enhancements. We develop a two-level system for a piecewise constant potential model for resonant tunneling that matches the energy levels in the vicinity of a level crossing, arguing that such models are applicable for more general potential models. Resonant tunneling effects and dynamics, including acceleration due to coherence, are accounted for in the model. The model is extended to include relaxation effects, and it is found that one would not expect to find coherent effects associated with tunneling in the case of two deuterons in a metal lattice. We present a simple model for the transfer of excitation from a collection of deuterons to a collection of helium nuclei, a model closely related to resonant tunneling and also to new phonon-coupled SU(N) models under development. The excitation transfer models show coherent enhancements as well as collective effects.