[Paper Review] Deformed states in paraelectric and ferroelectric nematic liquid crystals

Oleg D. Lavrentovich|arXiv (Cornell University)|Mar 22, 2026

Liquid Crystal Research Advancements0 citations

TL;DR

A review of how molecular shape, chirality, and confinement induce deformed, parity-breaking, splay/bend/twist-bend states in paraelectric and ferroelectric nematic liquid crystals, including the splay cancellation effect.

ABSTRACT

Ground states of materials with orientational order ranging from solid ferromagnets and ferroelectrics to liquid crystals often contain spatially varying vector-like order parameter caused by inner factors such as the shape of building units or by the geometry of confinement. This review presents examples of how the shapes, chirality, and polarity of molecules and spatial confinement induce deformed equilibrium and polydomain states with parity breaking, splay, bend, and twist-bend deformations of the order parameter in paraelectric and ferroelectric nematic liquid crystals. Parity breaking results either from chirality of the constituent molecules, as a replacement of energetically costly splay and bend in paraelectric nematics, or in response to depolarization field in the ferroelectric nematic. Both paraelectric and ferroelectric nematics exhibit a splay cancellation effect, in which the elastic and electrostatic energies of splay along one direction are reduced by an additional splay along orthogonal directions.

Motivation & Objective

• Explain how orientational order in nematic liquids leads to spatially varying order parameters.
• Summarize how molecular shape, chirality, and confinement induce deformed equilibrium and polydomain states.
• Discuss parity breaking and splay, bend, and twist-bend deformations in paraelectric and ferroelectric nematics.
• Describe the splay cancellation mechanism in both paraelectric and ferroelectric nematics.

Proposed method

• Review theoretical and experimental findings on deformed nematic states.
• Summarize mechanisms by which chirality and polarity stabilize deformations.
• Explain depolarization-field effects in ferroelectric nematics and splay energy considerations.
• Discuss the role of confinement and molecular geometry in generating polydomain states.

Experimental results

Research questions

• RQ1 What mechanisms drive parity-breaking deformations in paraelectric and ferroelectric nematic LC?
• RQ2 How do chirality and polarity influence splay, bend, and twist-bend distortions?
• RQ3 What is the splay cancellation effect and how does it manifest in these materials?
• RQ4 How do confinement and molecular geometry contribute to deformed equilibrium and polydomain states?

Key findings

• Parallels exist between paraelectric and ferroelectric nematics in exhibiting deformed equilibrium and polydomain states.
• Parity breaking can arise from molecular chirality or from responses to depolarization fields in ferroelectric nematics.
• Splay cancellation reduces elastic and electrostatic energy when splay occurs along orthogonal directions.
• Examples show a range of splay, bend, and twist-bend deformations driven by shape, chirality, and confinement.