Signatures of polar order in a ferroelectric nematic liquid crystal: splay stiffening and twist softening

Abstract

The recent discovery of ferroelectric nematics—genuine 3D ferroelectric fluids—has underscored the importance of electrostatic interactions in shaping the physical behaviour of soft matter systems. In this paper, we investigate the mechanical properties of ferroelectric nematics by directly comparing the splay and twist elastic constants in a liquid crystal system that exhibits both nonpolar and ferroelectric nematic phases. Our results reveal that polar ordering results in increased splay rigidity and a concomitant reduction in twist elasticity.