Atomic Physics Seminars

The development of ultrashort, broadband light pulses in the vacuum ultraviolet enables resonant excitation and probing of the dynamics of isolated molecules. Since the total angular momentum of an isolated system is conserved, broadband excitation necessarily leads to a coherent wavepacket of angular momentum states. Coherences between states of different angular momentum physically manifest as a time varying alignment or orientation of the molecular axis, as well as a much faster variation in the alignment or orientation of the electronic probability distribution, which is synchronized with electronic dynamics occurring in the molecular frame. I will present a direct and selective measurement of this time varying electronic anisotropy, and the potential application of ultrafast scattering probes to this end. I will also briefly discuss the application of purely rotational coherences in the electronic ground state to extract molecular frame information, particularly in the context of photoionization.