Influence of the electric field on edge dislocations in smectics

TL;DR

This paper investigates how a perpendicular electric field affects edge dislocations in smectic liquid crystals, revealing that the field influences dislocation energy divergence and their equilibrium position within the film.

Contribution

It introduces a theoretical analysis of electric field effects on dislocation behavior and equilibrium positions in smectic films, including critical field thresholds.

Findings

Electric field causes dislocation energy divergence to become logarithmic.

Dislocations can be shifted towards the surface by the electric field.

Critical electric field squared depends linearly on surface tension and inversely on film thickness.

Abstract

The electric field applied perpendicularly to smectic layers breaks the rotational symmetry of the system. Consequently, the elastic energy associated with distortions induced by an edge dislocation diverges logarithmically with the size of the system. In freely suspended smectic films the dislocations in the absence of the electric field are located exactly in the middle of the film. The electric field above a certain critical value can shift them towards the surface. This critical field squared is a linear function of the surface tension and is inversly proportional to the thickness of the film. The equilibrium location of a dislocation in the smectic film subjected to the field is also calculated.