Femto- and Attosecond Spectroscopy of Chiral Molecules

The capability of generating attosecond (10-18s) pulses of light in the extreme-ultraviolet domain through high-harmonic generation (HHG) has opened a broad range of possibilities in studying the fastest dynamics in matter. Notably, the creation of light pulses with tailored, time-dependent polarization states has opened a new window into the most fundamental structural and electronic dynamics underlying molecular chirality. This article reviews the work of our group on three forms of chiroptical spectroscopy: (i) high-harmonic spectroscopy with tailored light fields, which has achieved a ~13% dichroism effect in discrimination of enantiomers and the chirality-sensitive observation of a dissociative reaction, (ii) femtosecond time-resolved photoelectron circular dichroism (PECD), applied to resolve the photodissociation dynamics of two chiral molecules and (iii) the development of circularly polarized attosecond pulse trains, applied to coherently control PECD on the attosecond timescale and measure chirality-sensitive attosecond photoionization delays. These methods advance chiroptical spectroscopy to the attosecond timescale and open new perspectives for probing and controlling molecular chirality on electronic timescales.