  We here report on a quantitative study of Enantiomer-Specific State Transfer
(ESST), performed in a pulsed, supersonic molecular beam. The chiral molecule
1-indanol is cooled to low rotational temperatures (1-2 K) and a selected
rotational level in the electronic and vibrational ground state of the most
abundant conformer is depleted via optical pumping on the $S_{1} \leftarrow
S_{0}$ transition. Further downstream, three consecutive microwave pulses with
mutually perpendicular polarizations and with a well-defined duration and phase
are applied. The population in the originally depleted rotational level is
subsequently monitored via laser induced fluorescence (LIF) detection. This
scheme enables a quantitative comparison of experiment and theory for the
transfer efficiency in what is the simplest ESST triangle for any chiral
molecule, that is, the one involving the absolute ground state level,
$\left|J_{K_{a}K_{c}}\right\rangle = \left|0_{00}\right\rangle$. Moreover, this
scheme improves the enantiomer enrichment by over an order of magnitude
compared to previous works. Starting with a racemic mixture, a straightforward
extension of this scheme allows to create a molecular beam with an
enantiomer-pure rotational level, holding great prospects for future
spectroscopic and scattering studies.

Chemical Physics