The central theme of our experimental research program is the study of coherent electron and nuclear dynamics in molecules. Coherent electron motion and the ensuing quantum dynamics set forth by either optical excitation or nonresonant strong-field ionization of molecules by few-cycle laser pulses will be probed with attosecond to femtosecond time resolution. The typical ~1-eV energy spacing between occupied frontier molecular orbitals translates to a periodicity of a few femtoseconds for the coherent electron motion. Charge migration that is mediated by electronic quantum coherences therefore occurs at rates that are at least two orders of magnitude faster than Marcus-type charge transfer. Moreover, the comparable time scales for motion of the electronic and nuclear wave packets presents, in many cases, the possibility of unraveling non-Born-Oppenheimer dynamics. The main experimental techniques that will be employed are core-level transient absorption and transient photoelectron spectroscopies, in which extreme ultraviolet pulses produced by high-order harmonic generation will be used as probe. The ultimate goal of our studies is to exploit quantum coherences to enhance the performance of nanoelectronics and artificial light harvesting systems
