Study of structural transition of a cholesteric blue phase by continuumsimulation and machine-learning-aided structural analysis

Abstract

We carry out a numerical study on the structural transformation between a perfectly ordered cubic cholesteric blue phase (BP), known as BP II, and another cubic BP (BP I). Our study is based on a Langevin-type equation for the dynamics of orientational order parameter of a second-rank tensor. To distinguish the local structure of BP, we resort to supervised machine learning. We successfully clarify the dynamics of the transformation to BP I with twin boundaries, initiated by the formation of a BP I nucleus. We also show that the twinned BP I transforms to a perfect BP II lattice by temperature variation.