Multistability in planar liquid crystal wells

Chuong Luo, Apala Majumdar, Radek Erban

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

A planar bistable liquid crystal device, reported in Tsakonas et al. [Appl. Phys. Lett. 90, 111913 (2007)], is modeled within the Landau-de Gennes theory for nematic liquid crystals. This planar device consists of an array of square micrometer-sized wells. We obtain six different classes of equilibrium profiles and these profiles are classified as diagonal or rotated solutions. In the strong anchoring case, we propose a Dirichlet boundary condition that mimics the experimentally imposed tangent boundary conditions. In the weak anchoring case, we present a suitable surface energy and study the multiplicity of solutions as a function of the anchoring strength. We find that diagonal solutions exist for all values of the anchoring strength W ⩾ 0 , while rotated solutions only exist for W ⩾ W c > 0 , where W c is a critical anchoring strength that has been computed numerically. We propose a dynamic model for the switching mechanisms based on only dielectric effects. For sufficiently strong external electric fields, we numerically demonstrate diagonal-to-rotated and rotated-to-diagonal switching by allowing for variable anchoring strength across the domain boundary.
Original languageEnglish
Article number061702
Number of pages15
JournalPhysical Review E
DOIs
Publication statusPublished - 8 Jun 2012

Fingerprint

Multistability
Liquid Crystal
liquid crystals
boundary conditions
Multiplicity of Solutions
Surface Energy
Nematic Liquid Crystal
profiles
tangents
dynamic models
Tangent line
Dirichlet Boundary Conditions
External Field
surface energy
micrometers
Electric Field
Dynamic Model
Boundary conditions
electric fields
Demonstrate

Keywords

  • Landau-de Gennes theory
  • nematic liquid crystals
  • Dirichlet boundary condition

Cite this

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title = "Multistability in planar liquid crystal wells",
abstract = "A planar bistable liquid crystal device, reported in Tsakonas et al. [Appl. Phys. Lett. 90, 111913 (2007)], is modeled within the Landau-de Gennes theory for nematic liquid crystals. This planar device consists of an array of square micrometer-sized wells. We obtain six different classes of equilibrium profiles and these profiles are classified as diagonal or rotated solutions. In the strong anchoring case, we propose a Dirichlet boundary condition that mimics the experimentally imposed tangent boundary conditions. In the weak anchoring case, we present a suitable surface energy and study the multiplicity of solutions as a function of the anchoring strength. We find that diagonal solutions exist for all values of the anchoring strength W ⩾ 0 , while rotated solutions only exist for W ⩾ W c > 0 , where W c is a critical anchoring strength that has been computed numerically. We propose a dynamic model for the switching mechanisms based on only dielectric effects. For sufficiently strong external electric fields, we numerically demonstrate diagonal-to-rotated and rotated-to-diagonal switching by allowing for variable anchoring strength across the domain boundary.",
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author = "Chuong Luo and Apala Majumdar and Radek Erban",
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Multistability in planar liquid crystal wells. / Luo, Chuong; Majumdar, Apala; Erban, Radek.

In: Physical Review E, 08.06.2012.

Research output: Contribution to journalArticle

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T1 - Multistability in planar liquid crystal wells

AU - Luo, Chuong

AU - Majumdar, Apala

AU - Erban, Radek

PY - 2012/6/8

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N2 - A planar bistable liquid crystal device, reported in Tsakonas et al. [Appl. Phys. Lett. 90, 111913 (2007)], is modeled within the Landau-de Gennes theory for nematic liquid crystals. This planar device consists of an array of square micrometer-sized wells. We obtain six different classes of equilibrium profiles and these profiles are classified as diagonal or rotated solutions. In the strong anchoring case, we propose a Dirichlet boundary condition that mimics the experimentally imposed tangent boundary conditions. In the weak anchoring case, we present a suitable surface energy and study the multiplicity of solutions as a function of the anchoring strength. We find that diagonal solutions exist for all values of the anchoring strength W ⩾ 0 , while rotated solutions only exist for W ⩾ W c > 0 , where W c is a critical anchoring strength that has been computed numerically. We propose a dynamic model for the switching mechanisms based on only dielectric effects. For sufficiently strong external electric fields, we numerically demonstrate diagonal-to-rotated and rotated-to-diagonal switching by allowing for variable anchoring strength across the domain boundary.

AB - A planar bistable liquid crystal device, reported in Tsakonas et al. [Appl. Phys. Lett. 90, 111913 (2007)], is modeled within the Landau-de Gennes theory for nematic liquid crystals. This planar device consists of an array of square micrometer-sized wells. We obtain six different classes of equilibrium profiles and these profiles are classified as diagonal or rotated solutions. In the strong anchoring case, we propose a Dirichlet boundary condition that mimics the experimentally imposed tangent boundary conditions. In the weak anchoring case, we present a suitable surface energy and study the multiplicity of solutions as a function of the anchoring strength. We find that diagonal solutions exist for all values of the anchoring strength W ⩾ 0 , while rotated solutions only exist for W ⩾ W c > 0 , where W c is a critical anchoring strength that has been computed numerically. We propose a dynamic model for the switching mechanisms based on only dielectric effects. For sufficiently strong external electric fields, we numerically demonstrate diagonal-to-rotated and rotated-to-diagonal switching by allowing for variable anchoring strength across the domain boundary.

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