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Opportunities for imaging chiral nuclear dynamics on ultrafast timescales with synthetic chiral light

ORAL

Abstract

Chiral molecules appear in pairs of left- and right-handed enantiomers. These “mirror twins” behave identically, unless they interact with another chiral “object”. Distinguishing them is vital, but also hard [1]. Traditional optical methods rely on the helical structure that circularly polarized light draws in space. However, the pitch of this helix is too large, which leads to weak enantio-sensitivity (usually below 0.1%) and poses major challenges for imaging chiral dynamics, especially on ultrafast time scales. 

The recently introduced synthetic chiral light [2,3] allows us to bypass this fundamental limitation by encoding chirality in time, rather than relying on the spatial helix of a circularly polarized wave. Such light is locally chiral: the tip of the electric-field vector draws a chiral (3D) Lissajous figure in time, at every point in space. It produces giant enantio-sensitivity (100%) at the level of total intensity signals [2]. We have also shown that light's local handedness can be structured to realize a chiral version of Young’s double-slit experiment that leads to enantio-sensitive light bending [3]. 

Here we show how to exploit the giant enantio-sensitivity enabled by synthetic chiral light to probe chiral nuclear rearrangements during chemical reactions in a highly enantio-sensitive manner. Using time-dependent density functional theory, we explore how the nonlinear response of the prototypical chiral molecule H2O2 changes as a function of its dihedral angle, which defines its handedness. The direct mapping between chiral dichroism and nuclear geometry provides a way of probing chiral nuclear dynamics at their natural time scales. Our work paves the way for ultrafast and highly efficient imaging of enantio-sensitive dynamics in complex chiral systems, including biologically relevant molecules.

[1] Berova et al, Comprehensive Chiroptical Spectroscopy (Wiley, 2013)

[2] Ayuso et al, Nat Photon 13, 866 (2019)

[3] Ayuso et al, Nat Commun 12, 3951 (2021)

Publication: David Ayuso, Misha Ivanov and Olga Smirnova, "Opportunities for imaging chiral nuclear dynamics on ultrafast timescales with synthetic chiral light", manuscript in preparation.

Presenters

  • David Ayuso

    Imperial College London

Authors

  • David Ayuso

    Imperial College London

  • Misha Ivanov

    Max-Born-Institut

  • Olga Smirnova

    Max-Born-Institut