Chiral ground states of ferroelectric liquid crystals

TL;DR

This paper reveals that ferroelectric nematic liquid crystals naturally exhibit chiral ground states with left- and right-handed twists, driven by electrostatic interactions, even without chemically induced chirality.

Contribution

It demonstrates that the polar orientational order in achiral molecules can spontaneously induce chirality in ferroelectric nematic liquid crystals.

Findings

Chiral ground states exist in ferroelectric nematic liquid crystals.

Twists reduce electrostatic energy and are affected by doping.

Chirality can emerge without chemical chiral centers.

Abstract

Ferroelectric nematic liquid crystals are formed by achiral molecules with large dipole moments. Its three-dimensional orientational order is universally described as unidirectionally polar. We demonstrate that the ground state of ferroelectric nematic unconstrained by externally imposed alignment directions is chiral, with left- and right-hand twists of polarization. Although the helicoidal deformations and defect walls separating domains of opposite handedness increase the elastic energy, the twists reduce the electrostatic energy and become weaker when the material is doped with ions. The study shows that the polar orientational order of molecules could trigger chirality in the soft matter with no chemically induced chiral centers.