Study of Dicke’s Model for Superradiance at Short Wavelengths from Core-excited Atoms

Abstract: The main objective of this study is to contribute toward a comprehensive understanding of the superradiance problem in a short wavelength regime ($100$ to $100$ eV). In this regime, superradiance is influenced by Auger effect which would compete with normal superradiance process, and we want to study if it is possible to generate ultra-short pulses on the femtosecond or attosecond timescale using Dicke superradiance. Major result of our work is that we proposed a simple method to describe the Auger effect on a group of two-level atoms based on the original Dicke's model, and with the help of which several interesting new results have been found. We found that Auger decay can help to shorten the pulse duration, but only at the expense of weaker pulse intensity generated. Femtosecond pulses seem reasonable to reach according to our results.