Emergence of the bifurcation structure of a Langmuir-Blodgett transfer model

TL;DR

This paper investigates the complex bifurcation structure of a modified Cahn-Hilliard model describing non-equilibrium phase transitions, revealing a harp-like diagram with intertwined steady and periodic solutions relevant to Langmuir-Blodgett transfer.

Contribution

It provides a detailed numerical analysis of the bifurcation structure, including the emergence of time-periodic solutions and global bifurcations, in a model for surfactant pattern deposition.

Findings

Snaking structure of steady states intertwined with periodic solution branches.

Emergence of time-periodic solutions from Hopf and period doubling bifurcations.

Harp-like bifurcation diagram elucidated through two-parameter study.

Abstract

We explore the bifurcation structure of a modified Cahn-Hilliard equation that describes a system that may undergo a first order phase transition and is kept permanently out of equilibrium by a lateral driving. This forms a simple model, e.g., for the deposition of stripe patterns of different phases of surfactant molecules through Langmuir-Blodgett transfer. Employing continuation techniques the bifurcation structure is numerically investigated employing the non-dimensional transfer velocity as the main control parameter. It is found that the snaking structure of steady fronts states is intertwined with a large number of branches of time-periodic solutions that emerge from Hopf or period doubling bifurcations and end in global bifurcations (sniper and homoclinic). Overall the bifurcation diagram has a harp-like appearance. This is complemented by a two-parameter study (in non-dimensional transfer velocity and domain size) that elucidates through which local and global codimension 2 bifurcations the entire harp-like structure emerges.