Theory of Polar Blue Phases

TL;DR

This paper explores the stability and formation of novel polar blue phases in liquid crystals, revealing new modulated structures beyond previously known phases through simulations and theoretical analysis.

Contribution

It introduces the concept of polar blue phases with 2D and 3D modulations, expanding understanding of liquid crystal phases beyond twist-bend and splay-bend.

Findings

Discovery of polar blue phases with complex modulations

Comparison between polar and chiral blue phases

Potential experimental observation pathways

Abstract

In liquid crystals, if flexoelectric couplings between polar order and director gradients are strong enough, the uniform nematic phase can become unstable to formation of a modulated polar phase. Previous theories have predicted two types of modulation, twist-bend and splay-bend; the twist-bend phase has been found in recent experiments. Here, we investigate other types of modulation, using lattice simulations and Landau theory. In addition to twist-bend and splay-bend, we also find polar blue phases, with 2D or 3D modulations of both director and polar order. We compare polar blue phases with chiral blue phases, and discuss opportunities for observing them experimentally.