Rational pulse design for enantiomer-selective microwave three-wave mixing

TL;DR

This paper presents a method to optimize microwave pulse sequences for enantiomer-selective excitation of chiral molecules, enhancing selectivity by analyzing the dependence of Rabi frequencies on molecular orientation.

Contribution

It introduces a design strategy for pulse sequences that maximize enantiomer-selectivity by considering the M-dependence of Rabi frequencies in three-wave mixing.

Findings

Maximal enantiomer-selectivity achieved with synchronized three-wave mixing.

Circularly polarized fields outperform other excitation schemes.

Optimal pulse design accounts for molecular orientation effects.

Abstract

Microwave three-wave mixing allows for enantiomer-selective excitation of randomly oriented chiral molecules into rotational states with different energy. The random orientation of molecules is reflected in the degeneracy of the rotational spectrum with respect to the orientational quantum number $M$ and reduces, if not accounted for, enantiomer-selectivity. Here, we show how to design pulse sequences with maximal enantiomer-selectivity from an analysis of the $M$-dependence of the Rabi frequencies associated with rotational transitions induced by resonant microwave drives. We compare different excitations schemes for rotational transitions and show that maximal enantiomer-selectivity at a given rotational temperature is achieved for synchronized three-wave mixing with circularly polarized fields.