Emergent elasticity linked to topological phase transitions controlled via molecular chirality and steric anisotropy

TL;DR

This paper demonstrates how emergent elasticity, arising from steric and twisting interactions, can be used to control topological phases like skyrmions in molecular solids through external stimuli.

Contribution

It introduces a novel control mechanism for topological phases in molecular solids based on emergent elasticity linked to molecular chirality and anisotropy.

Findings

Control of topological phases via temperature, electromagnetic fields, and stresses.

Emergent elastic fields influence molecular orientation and topological structures.

Potential for designing materials with tunable electro- and magneto-mechanical properties.

Abstract

Self-organisation into spatially modulated structures has different nature from phase transition into uniform states. Skyrmions and half-skyrmions (merons) are representatives of such structures and are utilised in designing magnetoelectric, optical, and mechanoresponsive materials by controlling topological phases. However, skyrmions and half-skyrmions in molecular solids are rarely studied, though there is a universality in theoretical descriptions between magnetic and molecular systems with chiral interactions. Here we develop a simple physical system for controlling topological phases in a solid with chirality. We reveal that emergence of elastic fields from anisotropic steric interactions and intermolecular twisting is a key to control helical and half-skyrmion structures. Utilising the coupling between the emergent elastic fields and molecular orientations, we successfully control topological phases by temperature, external electromagnetic fields, and anisotropic stresses. The concept of the emergent elasticity provides a control system for designing molecular and macromolecular solids with tunable electro- and magneto-mechanical properties.