  Molecular chirality is an omnipresent phenomenon of fundamental significance
in physics, chemistry and biology. For this reason, search for novel techniques
for enantioselective control, detection and separation of chiral molecules is
of particular importance. It has been recently predicted that laser fields with
twisted polarization may induce persistent enantioselective field-free
orientation of chiral molecules. Here we report the first experimental
observation of this phenomenon using propylene oxide molecules
($\mathrm{CH_{3}CHCH_{2}O}$, or PPO) spun by an optical centrifuge - a laser
pulse, whose linear polarization undergoes an accelerated rotation around its
propagation direction. We show that PPO molecules remain oriented on a time
scale exceeding the duration of the centrifuge pulse by several orders of
magnitude. The demonstrated long-time field-free enantioselective orientation
opens new avenues for optical manipulation, discrimination, and, potentially,
separation of molecular enantiomers.
