Laser Stabilised Ionising Transitions

The dominant paradigm is the Fano model of bound-to-continuum transitions and resonant fluorescence. The preprint introduces a drift by demonstrating the emergence of a novel metastable state under resonant pumping.

The preprint operates within the established paradigm of Fano's theory of bound-to-continuum transitions and utilizes resonant fluorescence as a standard tool for investigating quantum emitters. However, the central finding challenges the conventional understanding within this paradigm. The authors demonstrate that above a critical pump intensity, a metastable bound state emerges, which can decay via two-photon ionization. This contrasts with the assumption in Fano's approach that the spectrum of the coupled system is entirely continuous. While the preprint acknowledges the existence of discrete bound states outside the continuum for large coupling strengths (as shown in the Lee-Friedrichs Hamiltonian), the emergence of this state under resonant pumping and its metastable nature introduces a drift from the existing Fano model. The authors draw parallels with photon-bound excitons, hinting at a potential shift towards a more encompassing model that accounts for this laser-stabilized state, but the overall framework remains within the existing paradigm of resonant fluorescence, thus classifying the research as Model Drift, with hints of a possible incipient Model Revolution. The exploration of these metastable states could signify a move towards a refined paradigm, but currently, the changes are best understood as a modification rather than a complete overthrow of the Fano model. The investigation of these metastable states is still in early stages, with the present study offering primarily theoretical predictions. Future experimental validation of these states and their dynamics will be crucial to consolidate the drift and potentially lead to a model revolution.