Continuum-electron interferometry for enhancement of photoelectron circular dichroism and measurement of bound, free, and mixed contributions to chiral response

We develop photoelectron interferometry based on laser-assisted extreme ultraviolet ionization for randomly oriented chiral molecules. As in the well established 'reconstruction of attosecond beating by interference of two-photon transitions', an infrared or visible laser pulse promotes interferences between components of the photoelectron wave packet ionized by a comb of XUV photons, applied here to a sample of chiral molecules. We show that the magnitude of the resulting chiral signal is simply controlled by the time delay between the XUV and laser pulses, the choice of the laser frequency determines the photoelectron energy at which the chiral signal is probed, and comparison of different polarization configurations in the two-photon process allows for disentangling the contributions of bound and continuum states to the chiral response. Our proposal provides a simple, experimentally feasible, robust and versatile tool for the control of photoelectron circular dichroism.