Flexoelectrically driven electroclinic effect in the twist-bend nematic phase of achiral molecules with bent shapes.
Phys Rev Lett
; 111(6): 067801, 2013 Aug 09.
Article
en En
| MEDLINE
| ID: mdl-23971614
We extend the twist-bend nematic (N(TB)) model to describe the electro-optics of this novel phase. We predict an electroclinic effect (ECE) subject to a dc electric field E applied perpendicular to the helix axis or wave vector q, with rotation of the N(TB) optic axis around E. This linear effect, with its flexoelectric origin, is a close analog to the electro-optic effects observed for chiral liquid crystals. However, in nematics composed of achiral molecules having a bent shape, it is the electro-optic signature of the N(TB) phase. We test our model experimentally in the low-temperature nematic phase of the odd liquid crystal dimer, CB7CB, with its molecules having, on average, a bent shape. The ECE measurements confirm the previously proposed twist-bend nematic structure of this phase, with its broken chiral symmetry, extremely short (<10 nm) doubly degenerate pitch and ultrafast, submicrosecond response times.
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Base de datos:
MEDLINE
Asunto principal:
Cristales Líquidos
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Modelos Químicos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Phys Rev Lett
Año:
2013
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos