Lossy Spin-boson Model with an Unstable Upper State and Extension to N-level Systems

In the Fleischmann-Pons experiment, excess heat is thought to have a nuclear origin due to the amount of energy produced, yet there are no commensurate energetic particles. This has motivated us over the years to focus attention on models in which a large quantum is fractionated into a great many small quanta. We have found that many two-level systems with a large transition energy are able to exchange energy coherently with an oscillator with a much smaller characteristic energy as long as decay channels are present in the vicinity of the two-level transition energy. In previous work we analyzed this basic model, and obtained estimates for the coherent energy exchange rate in the strong coupling limit. In this work we consider a version of this model where the upper states of the two-level systems are unstable. In this case, there is no coherent energy exchange, but instead we find a dynamical polarization effect which we have analyzed. We extend the model to the case of three-level systems, and generalize the result to apply to general N-level systems. Coherent energy exchange is possible within the context of a donor and receiver model, where the receiver transitions have unstable upper states. We give results for the donor dynamics in this case. This model provides a foundation for a new kind of model that we put forth recently for which the predictions appear to be closely connected to experiment. (C) 2013 ISCMNS. All rights reserved.