Attosecond electron dynamics in molecules and liquids

The ultrafast motion of electrons and holes following light-matter interaction is fundamental to a broad range of chemical and biophysical processes. In this lecture, I will discuss some of our recent experiments that measure the atomic-scale motion of charge with attosecond temporal resolution (1 as = 10$^{-18}$s). The first experiment is carried out on isolated, spatially oriented molecules in the gas phase. Using high-harmonic spectroscopy, we resolve the migration of an electron hole across the molecule with a resolution of $\sim$100 as and simultaneously demonstrate extensive control over charge migration [1]. In the second class of experiments, we use an attosecond pulse train synchronized with a near-infrared laser pulse to temporally resolve the process of photoemission from molecules in the gas phase [2] and from a liquid-water microjet, resolving electron transport through liquid water on the attosecond time scale.\\ [1] P. M. Kraus, B. Mignolet, D. Baykusheva, A. Rupenyan, L. Horny, E. F. Penka, G. Grassi, O. I. Tolstikhin, J. Schneider, F. Jensen, L. B. Madsen, A. D. Bandrauk, F. Remacle, and H. J. W\"orner, {\it Science} {\bf 350}, 790 (2015).\\ [2] M. Huppert, I. Jordan, A. von Conta and H.J. W\"orner, {\it Phys. Rev. Lett.} {\bf 117}, 093001 (2016)