Quantum control of ro-vibrational dynamics and application 
to light-induced molecular chirality

Abstract

Achiral molecules can be made temporarily chiral by excitation with electric fields, 
in the sense that an average over molecular orientations displays a net chiral signal 
Tikhonov et al., Sci. Adv. 8, eade0311 (2022). Here, we go beyond the assumption of
molecular orientations to remain fixed during the excitation process. Treating both 
rotations and vibrations quantum mechanically, we identify conditions for the creation 
of chiral vibrational wavepackets -- with net chiral signals -- in ensembles of achiral 
molecules which are initially randomly oriented. Based on the analysis of symmetry and 
controllability, we derive excitation schemes for the creation of chiral wavepackets 
using a combination of (a) microwave and IR pulses and (b) a static field and a 
sequence of IR pulses. These protocols leverage quantum rotational dynamics for 
pump-probe spectroscopy of chiral vibrational dynamics, extending the latter to 
regions of the electromagnetic spectrum other than the UV.