Determination of enantiomeric excess with chirality-dependent ac Stark effects in cyclic three-level models

Abstract

Determination of enantiomeric excess is important and remains challenges. We theoretically propose a new spectroscopic method for this issue based on the chirality-dependent AC Stark effects in cyclic three-level models under the three-photon resonance condition. The enantiomeric excess of the chiral mixture is determined by comparing the amplitudes of the two chosen AC Stark peaks in the Fourier transform spectrum of the induced polarizations, which are (approximately) proportional to the molecule numbers of the two enantiomers, respectively. Comparing with current spectroscopic methods based on the interference between the electric-and (usually weak) magneticdipole transition moments and/or with the need for enantio-pure samples, our method only involves electric-dipole transitions and does not require the enantio-pure samples. Therefore, it will give strong chiral signals and can be applied to the determinations of enantiomeric excess for chiral molecules whose enantio-pure samples are still challenging to achieve.

Enantiodiscrimination of chiral molecules via quantum correlation function

“…In general, only one enantiomeric form is biologically beneficial, while the other one is harmful or even fatal. Thus, enantiodiscrimination [4][5][6][7][8][9][10][11][12][13][14][15], enantiospecific state transfer [16][17][18][19][20][21][22][23][24][25][26][27], spatial enantioseparation [28][29][30][31][32][33][34][35], and enantioconversion [36][37][38][39][40][41][42][43] of chiral molecules have become very important and challenging tasks.…”

“…In recent years, some theoretical schemes have been proposed to implement the enantiodiscrimination [4][5][6][7][8][9][10][11][12][13][14][15], enantiopurification (including enantiospecific state transfer [16][17][18][19][20][21][22][23][24][25][26][27] and enantioconversion [36][37][38][39][40][41][42][43]), and spatial enantioseparation [28][29][30][31][32]35] of chiral molecules through the optical means.…”

Fast enantioconversion of chiral mixtures based on a four-level double- Δ model

“…Well-established optical methods [16][17][18], such as circular dichroism, vibrational circular dichroism, and Raman optical activity, were used for determination of enantiomeric excess in chiral mixtures (enantiodiscrimination). Based on the three-level -type (also called cyclic three-level) models, theoretical methods for enantiodiscrimination [24,43], enantiospecific state transfer [19,21,23,38,44,45], and enantioseparation [20,22] were proposed. Very recently, breakthrough experiments devoted to realizing enantiodiscrimination [46][47][48][49][50][51][52] and enantiospecific state transfer [53,54] have been achieved based on the threelevel -type models.…”

Two-Path Interference for Enantiomer-Selective State Transfer of Chiral Molecules

“…Lately, a lot of remarkable experiments were contributed to the verification of enantiomeric differentiation and the probe of enantiomeric excess based on the technique of microwave three-wave mixing (M3WM) [41][42][43][44][45][46][47][48]. Promoted by experimental achivements, some proposals were put forward very recently for the related issues, such as the design of cyclic three-level configurations in chiral molecules [49], shortcut-to-adiabatic (STA) enantiomerselective population transfer of chiral molecules by means of shaped pulses [50,51], and dynamic methods for the enantiomeric excess determination [40] and the innerstate enantio-separation [52].…”