Introducing Variable Cell Shape Methods in Field Theory Simulations of Polymers

TL;DR

This paper introduces a novel field-theoretic simulation method for polymers that allows the simulation box to change shape under external stress, enabling the study of stress-induced morphology transitions.

Contribution

A new simulation approach that incorporates variable cell shapes and a derived stress tensor expression for studying polymer morphologies under stress.

Findings

Enables fully relaxed, stress-free configurations in complex morphologies

Allows monitoring of shape changes via a derived deviatoric stress tensor

Facilitates investigation of morphology transitions induced by external stress

Abstract

We propose a new method for carrying out field-theoretic simulations of polymer systems under conditions of prescribed external stress, allowing for shape changes in the simulation box. A compact expression for the deviatoric stress tensor is derived in terms of the chain propagator, and is used to monitor changes in the box shape according to a simple relaxation scheme. The method allows fully relaxed, stress free configurations to be obtained even in non trivial morphologies, and enables the study of morphology transitions induced by external stresses.