Relaxation dynamics, dissipative tunneling, solitons, and anomalous decay

An anomalous behavior of the emission properties of alkali halides doped with heavy impurities, stimulated new efforts for its interpretation, invoking delicate and sophisticated mechanisms whose interest transcends the considered specific case. Of crucial importance is the evolution of the lattice reaction time. This gives strong support to a Jahn-Teller model which is able to interpret the slow (complex) decay of the emissions in the $A$ band. The mechanism adopted is borrowed from the dissipative-tunneling approach, previously developed for loaded superconducting Josephson junctions, and suitably modified. Moreover, an attempt is made for a modification of the model by considering a mechanism based on soliton confinement.