Quantum entropic exchange at avoided crossings due to laser–atom interaction

In the present study, we detail the entropic characteristics of a dressed atom, wherein the atom undergoes an interaction with a monochromatic laser beam. Our investigation of the laser–atom interplay employs a well-established non-perturbative quasi-energy methodology, allowing us to discern the dressed wavefunctions and quasi-energies of the laser-dressed atom. Utilizing these dressed wavefunctions as a foundation, we systematically examine various entropic measures, observing their behaviour for laser frequency and intensity. The selection of levels within the system adheres to the criteria dictated by the selection rules governing transitions between these levels. Our exploration focuses on the interplay between Shannon entropy and other entropic metrics, with their fluctuations intricately tied to the phenomenon of avoided crossings. As the laser amplitude intensifies, the AC Stark effect takes centre stage, exerting influence over the sharp or smooth variations in Shannon entropy at these avoided crossings. Furthermore, we delineate the correlation between the number of levels considered and the identification of avoided crossings. Our present analysis sheds light on the intricate dynamics in the dressed atom system, enhancing our understanding of the interplay between laser-induced dressing and entropic measures.