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Updated: Aug 19, 2025

Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
Discrimination of Chiral and Helical Contributions to Raman Scattering of Liquid Crystals Using Vortex Beams
Silvia Müllner1, Florian Büscher1, Angela Möller2
1Institute for Condensed Matter Physics, University of Technology Braunschweig, D-38106 Braunschweig, Germany.
Abstract:
We use vortex photon fields with orbital and spin angular momentum to probe chiral fluctuations within liquid crystals. In the regime of iridescence with a well-defined pitch length of chirality, we find low energy Raman scattering that can be decomposed into helical and chiral components depending on the scattering vector and the topological charge of the incident photon field. Based on the observation of an anomalous dispersion we attribute quasielastic scattering to a transfer of angular momenta to rotonlike quasiparticles. The latter are due to a competition of short-range repulsive and long-range dipolar interactions. Our approach using a transfer of orbital angular momentum opens up an avenue for the advanced characterization of chiral and optically active devices and materials.
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