Detecting chirality in molecules by linearly polarized laser fields

TL;DR

This paper introduces a laser-based method to differentiate enantiomers by inducing unidirectional molecular rotation, leveraging differences in electric polarizability, applicable at high temperatures and suitable for studying short-lived chiral states.

Contribution

It presents a novel ultrafast laser technique for enantiomer discrimination using polarized pulses that exploits anisotropic polarizability differences, enabling analysis of complex and transient chiral molecules.

Findings

Differentiates enantiomers via phase-shifted unidirectional rotation

Effective at high temperatures and for low barrier molecules

Suitable for studying short-lived chiral states and parity violation

Abstract

A new scheme for enantiomer differentiation of chiral molecules using a pair of linearly polarized intense ultrashort laser pulses with skewed mutual polarization is presented. The technique relies on the fact that the off-diagonal anisotropic contributions to the electric polarizability tensor for two enantiomers have different signs. Exploiting this property, we are able to excite a coherent unidirectional rotation of two enantiomers with a {\pi} phase difference in the molecular electric dipole moment. The approach is robust and suitable for relatively high temperatures of molecular samples, making it applicable for selective chiral analysis of mixtures, and to chiral molecules with low barriers between enantiomers. As an illustration, we present nanosecond laser-driven dynamics of a tetratomic non-rigid chiral molecule with short-lived chirality. The ultrafast time scale of the proposed technique is well suited to study parity violation in molecular systems in short-lived chiral states.