Investigations on pi-cell, a sandwich cell with the director rotating by 180°, are demonstrating the possibility to obtain nematic transitions between two textures with different topologies, for instance between an untwisted state and a pi-twisted one. Fast topological changes can be observed by means of suitable electric fields or by micro/nano-confinement in the nematic bulk or close to a boundary surface. A strong frustration, in fact, as in the case of a strong local distortion, can induce transient and/or local biaxial states inside a nematic calamitic phase and the resultant nematic dynamics demands a full Landau-de Gennes Q-tensor description. In this work, we present Q-tensor numerical models capable to describe the nematic order dynamics in full details, comparing theoretical results with experiments. We will also discuss as nematic order reconstruction close to a boundary surface with strong or infinite anchoring conditions can provide transitions equivalent to anchoring breaking.

Recent advances on nematic order reconstruction / R., Barberi; G., Lombardo; R., Hamdi; F., Cosenza; F., Ciuchi; Amoddeo, Antonino. - (2010).

Recent advances on nematic order reconstruction

AMODDEO, Antonino
Software
2010-01-01

Abstract

Investigations on pi-cell, a sandwich cell with the director rotating by 180°, are demonstrating the possibility to obtain nematic transitions between two textures with different topologies, for instance between an untwisted state and a pi-twisted one. Fast topological changes can be observed by means of suitable electric fields or by micro/nano-confinement in the nematic bulk or close to a boundary surface. A strong frustration, in fact, as in the case of a strong local distortion, can induce transient and/or local biaxial states inside a nematic calamitic phase and the resultant nematic dynamics demands a full Landau-de Gennes Q-tensor description. In this work, we present Q-tensor numerical models capable to describe the nematic order dynamics in full details, comparing theoretical results with experiments. We will also discuss as nematic order reconstruction close to a boundary surface with strong or infinite anchoring conditions can provide transitions equivalent to anchoring breaking.
2010
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12318/23322
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