Fast enantioconversion of chiral mixtures based on a four-level double-$\Delta$ model

TL;DR

This paper introduces a rapid, purely optical method for enantioconversion of chiral mixtures based on a simplified four-level double-$\Delta$ model, significantly reducing operation time compared to previous methods.

Contribution

The authors develop a fast, purely optical enantioconversion technique using a simplified four-level model, eliminating the need for relaxation steps and repeated operations.

Findings

Achieves enantioconversion three orders of magnitude faster than previous methods.

Uses only optical operations without relaxation steps.

Applicable under limited operation time due to racemization or experimental constraints.

Abstract

Based on the four-level double-$\Delta$ model composed of two degenerated (left- and right-handed) chiral ground states and two achiral excited states, we propose a purely optical method for enantio-conversion of chiral mixture. By choosing appropriate parameters, the original four-level model will be simplified to two effective two-level sub-systems with each of them involving one chiral ground state. Then, with the help of well-designed optical operations, the initial unwanted and wanted chiral ground states are converted, respectively, to the wanted chiral ground state and an auxiliary chiral excited state with the wanted chirality, i.e., achieving the enantioconversion of the chiral mixture. Comparing with the original work of enantioconversion based on the four-level double-$\Delta$ model with the requirement of the time-consuming relaxation step and repeated operations, our method can be three orders of magnitude faster since we use only purely optical operations. Thus, it offers a promising candidate for fast enantioconversion when the total operation time is limited due to the racemization and/or experimental conditions.