Frustrated Rotations in Nematic Monolayers

TL;DR

This paper investigates the relaxation dynamics of frustrated optical axis rotations in chiral nematic monolayers, revealing complex burst behaviors due to defect nucleation and tension release, supported by simulations.

Contribution

It introduces a model for tension relaxation in nematic monolayers involving disclination pairs and predicts non-periodic burst sequences.

Findings

Long delay times before relaxation

Non-periodic burst sequences observed

Numerical simulations support the model

Abstract

Tabe and Yokoyama found recently that the optical axis in a chiral monolayer of a ferronematic rotates when water evaporates from the bath: the chiral molecules act as propellers. When the axis is blocked at the lateral walls of the trough, the accumulated rotation inside creates huge splays and bends. We discuss the relaxation of these tensions, assuming that a single dust particle nucleates disclination pairs. For the simplest geometry, we then predict a long delay time followed by a non-periodic sequence of ``bursts''. These ideas are checked by numerical simulations.