  Chiral discrimination, a problem of vital importance, has recently become an
emerging frontier in ultrafast physics, with remarkable progress achieved in
multiphoton and strong-field regimes. Rydberg excitations, unavoidable in the
strong-field regime and intentional for few-photon processes, arise in all
these approaches. Here we show how to harness this ubiquitous feature by
introducing a new phenomenon, enantiosensitive free-induction decay, steered by
a tricolour chiral field at a gentle intensity, structured in space and time.
We demonstrate theoretically that an excited chiral molecule accumulates an
enantiosensitive phase due to perturbative interactions with the tricolour
chiral field, resulting in a spatial phase gradient steering the free-induction
decay in opposite directions for opposite enantiomers. Our work introduces a
general, extremely sensitive, all-optical, enantiosensitive detection technique
which avoids strong fields and takes full advantage of recent advances in
structuring light.
