Probing and Controlling Chirality on Electronic Time Scales

Ziel

Molecular chirality plays a fundamental role in most chemical reactions and biochemical processes underlying life on earth. The underlying quantum processes unfold on electronic time scales, requiring a breakthrough: attosecond chiroptical pump–probe spectroscopy. We will generate the first characterized, isolated, circularly polarized attosecond pulses and apply them in kinematically complete electron–ion coincidence experiments. This will enable direct measurements of electronic wave packets in photoexcited chiral molecules. Attosecond electron motion in superposition states is predicted to create geometric magnetism that induces large, novel circular dichroisms—effects not yet observed on sub-10-fs time scales. Our attosecond chiroptical spectroscopy provides a unique route to test these and other fascinating predictions. We will also induce and control charge migration in chiral molecules to reveal how attosecond-pulse chirality shapes chiral charge-migration currents. We will probe their impact on spin polarization of ejected electrons and on molecular orientations, delivering the first ultrafast, time-resolved insight into mechanisms underlying chirality-induced spin selectivity (CISS). Together, these experiments on chiral electron wave packets and chiral charge migration target fundamental advances in understanding the electronic dynamics that drive chiral function. To broaden impact, we will systematically extend from isolated to micro- and fully hydrated chiral molecules, tracking how adding water molecules one-by-one modifies geometric magnetism, induced circular dichroism, attosecond photoionization delays, chiral wave packets, and charge migration. These studies will reveal how hydration shells reshape bound and continuum chiral electron dynamics, shift electronic states and time scales, and open new dissipation channels that dephase electronic coherences, clarifying the role of solvation in attosecond chiral dynamics directly relevant to life.