Quantum beats and dephasing in isolated large molecules cooled by supersonic jet expansion and excited by picosecond pulses: Anthracene

Intramolecular relaxation in isolated large molecules is of considerable current interest . The primary questions are: what is the nature of the states which are excited by the light source, and how does the deposited energy get transferred within the molecule? In this regard, the possibility of observing coherence effect the fluorescence decay of large molecules is very important. When large molecules are excited at finite temperatures the existence of many sequence transitions results in spectral broadening and in the masking of these possible coherence effects. Although recent supersonic molecular beam spectroscopy^1-3 has been successful in circumventing the congestion problem, the large density of excited statea may still prevent the observation of such effects…