Quantitative study of enantiomer-specific state transfer

TL;DR

This study demonstrates a quantitative method for enantiomer-specific state transfer in chiral molecules using microwave pulses, significantly enhancing enantiomer enrichment and enabling potential applications in spectroscopy and scattering experiments.

Contribution

The paper introduces a novel, quantitative ESST scheme in a pulsed molecular beam that improves enantiomer enrichment by over an order of magnitude compared to prior methods.

Findings

Achieved high-efficiency enantiomer-specific state transfer

Enhanced enantiomer enrichment by over tenfold

Created enantiomer-pure rotational levels from racemic mixtures

Abstract

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.