  Controlling the internal quantum states of chiral molecules for a selected
enantiomer has a wide range of fundamental applications. Using tailored
microwave fields, a chosen rotational state can be enriched for a selected
enantiomer, even starting from a racemic mixture. This enables rapid switching
between samples of different enantiomers in a given state, holding great
promise, for instance, for measuring parity violation in chiral molecules.
Achieving full enantiomer-specific state transfer is a key requirement for this
and many other applications. Although theoretically feasible, achieving the
required experimental conditions seemed unrealistic. Here, we realize
near-ideal conditions, overcoming both the limitations of thermal population
and spatial degeneracy in rotational states. Our results show that 96%
state-specific enantiomeric purity can be obtained from a racemic mixture, in
an approach that is universally applicable to all chiral molecules of C1
symmetry.
