“…impulsive electronic excitation and pulsed lasers) transformed the fluorescence quantum beating technique into a tool for high-precision optical spectroscopy [5,6,10]. In the optical regime, quantum beatsrelated phenomena were observed for the resonant fluorescence of atoms [11,12] and molecules [13][14][15], from an ensemble of two-level atoms [16,17], in quantum well systems [18], and even in the temporal profiles of superfluorescence [19][20][21]. In the XUV regime, quantum beats were used as a tool to evaluate the polarization of synchrotron radiation [22].…”