Unveiling the X-ray-Induced Rabi Dynamics in Resonant Auger Fragment Spectra.

Vibrationally resolved resonant Auger spectroscopy (RAS) on bound-continuum transitions enables highly sensitive probing of ultrafast dissociation in molecular core-excited states, where a distinct fragment band arises from Auger decay in dissociation fragments. Here, we theoretically investigate fragment band formation driven by ultrashort X-ray pulses. Unlike conventional molecular bands, fragment RAS peaks exhibit an insensitivity to strong X-ray Rabi oscillations.