  Chiral light-matter interactions have been investigated for two centuries,
leading to the discovery of many chiroptical processes used for discrimination
of enantiomers. Whereas most chiroptical effects result from a response of
bound electrons, photoionization can produce much stronger chiral signals that
manifest as asymmetries in the angular distribution of the photoelectrons along
the light propagation axis. Here we implement a self-referenced attosecond
photoelectron interferometry to measure the temporal profile of the forward and
backward electron wavepackets emitted upon photoionization of camphor by
circularly polarized laser pulses. We found a delay between electrons ejected
forward and backward, which depends on the ejection angle and reaches 24
attoseconds. The asymmetric temporal shape of electron wavepackets emitted
through an autoionizing state further reveals the chiral character of
strongly-correlated electronic dynamics.
