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Related papers: Spherical nematics with a threefold valence

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We propose a continuum model to describe the molecular alignment in thin nematic shells. By contrast with previous accounts, the two-dimensional free energy, aimed at describing the physics of thin films of nematics deposited on curved…

Soft Condensed Matter · Physics 2012-06-19 Gaetano Napoli , Luigi Vergori

A nematic liquid crystal confined to the surface of a sphere exhibits topological defects of total charge $+2$ due to the topological constraint. In equilibrium, the nematic field forms four $+1/2$ defects, located at the corners of a…

Soft Condensed Matter · Physics 2020-07-22 Yi-Heng Zhang , Markus Deserno , Zhan-Chun Tu

In two dimensional nematics, topological defects are point like singularities with both a charge and a phase. We study topological defects within curved nematic textures on the surface of a cylinder. This allows us to isolate the effect of…

Soft Condensed Matter · Physics 2022-05-10 Daniel J. G. Pearce

We present a theoretical study of the director fields and energetics of nematic liquid crystal shells with two pairs of surface defects. The pairs of defects can undergo abrupt transitions between a configuration of maximum separation to at…

Soft Condensed Matter · Physics 2012-11-21 V. Koning , T. Lopez-Leon , A. Fernandez-Nieves , V. Vitelli

We present a hydrodynamic model for a thin spherical shell of active nematic liquid crystal with an arbitrary configuration of defects. The active flows generated by defects in the director lead to the formation of stable vortices,…

Soft Condensed Matter · Physics 2017-11-13 Diana Khoromskaia , Gareth P. Alexander

We perform energy spectrum analysis of the active turbulence in 3D bulk active nematic using continuum numerical modelling. Specifically, we calculate the spectra of two main energy contributions---kinetic energy and nematic elastic…

Soft Condensed Matter · Physics 2020-09-15 Žiga Krajnik , Žiga Kos , Miha Ravnik

The equilibrium texture of nematic shells is studied as a function of their thickness. For ultrathin shells the ground state has four short 1/2 disclination lines but, as the thickness of the film increases, a three dimensional escaped…

Soft Condensed Matter · Physics 2009-11-11 Vincenzo Vitelli , David R. Nelson

We investigate experimentally and numerically the defect configurations emerging when a cholesteric liquid crystal is confined to a spherical shell. We uncover a rich scenario of defect configurations, some of them non-existent in nematic…

Soft Condensed Matter · Physics 2017-09-13 Alexandre Darmon , Michael Benzaquen , Simon Čopar , Olivier Dauchot , Teresa Lopez-Leon

Active nematics are fluids in which the components have nematic symmetry and are driven out of equilibrium due to the microscopic generation of an active stress. When the active stress is high, it drives flows in the nematic and can lead to…

Soft Condensed Matter · Physics 2025-11-10 Daniel J. G. Pearce , Berta Martínez-Prat , Jordi Ignés-Mullol , Francesc Sagués

We study the organization of topological defects in a system of nematogens confined to the two-dimensional sphere (S^2). We first perform Monte Carlo simulations of a fluid system of hard rods (spherocylinders) living in the tangent plane…

Soft Condensed Matter · Physics 2009-11-13 Homin Shin , Mark J. Bowick , Xiangjun Xing

In this paper we rigorously investigate the emergence of defects on Nematic Shells with genus different from one. This phenomenon is related to a non trivial interplay between the topology of the shell and the alignment of the director…

Analysis of PDEs · Mathematics 2017-03-17 Giacomo Canevari , Antonio Segatti

The transition from a nematic to an isotropic state in a self-closing spherical liquid crystal shell with tangential alignment is a stimulating phenomenon to investigate, as the topology dictates that the shell exhibits local isotropic…

Soft Condensed Matter · Physics 2024-02-02 Yucen Han , Jan Lagerwall , Apala Majumdar

In this work we study a charged particle in the presence of both a continuous distribution of disclinations and a continuous distribution of edge dislocations in the framework of the geometrical theory of defects. We obtain the self-energy…

General Relativity and Quantum Cosmology · Physics 2009-11-10 A. M. de M. Carvalho , Fernando Moraes , Claudio Furtado

Using computer simulations we investigate the microscopic structure of the singular director field within a nematic droplet. As a theoretical model for nematic liquid crystals we take hard spherocylinders. To induce an overall topological…

Soft Condensed Matter · Physics 2009-10-31 J. Dzubiella , M. Schmidt , H. Loewen

We study {{\rm C}$_{60}$} with the use of Thomas-Fermi theory. A spherical shell model is invoked to treat the nuclear potential, where the nuclear and core charges are smeared out into a shell of constant surface charge density. The…

chem-ph · Physics 2009-10-28 Dennis P. Clougherty , Xiang Zhu

We present results of micromagnetic simulations of thin ferromagnetic nano hemispheroidal shells with sizes ranging from 1 to 50 nm (inside dimensions). Depending on the geometrical and magnetic parameters of the hemispheroidal shell, there…

Mesoscale and Nanoscale Physics · Physics 2017-08-23 Keren Schultz , Moty Schultz

Active nematics contain topological defects which under sufficient activity move, create and annihilate in a chaotic quasi-steady state, called active turbulence. However, understanding active defects under confinement is an open challenge,…

Soft Condensed Matter · Physics 2019-10-02 Simon Čopar , Jure Aplinc , Žiga Kos , Slobodan Žumer , Miha Ravnik

We present a novel, self-consistent and robust theoretical model to investigate elastic interactions between topological defects in liquid crystal shells. Accounting for the non-concentric nature of the shell in a simple manner, we are able…

Soft Condensed Matter · Physics 2016-12-14 Alexandre Darmon , Olivier Dauchot , Teresa Lopez-Leon , Michael Benzaquen

A shape sensitive, variational approach for the matching of surfaces considered as thin elastic shells is investigated. The elasticity functional to be minimized takes into account two different types of nonlinear energies: a membrane…

Optimization and Control · Mathematics 2021-06-09 José A. Iglesias , Martin Rumpf , Otmar Scherzer

We derive the effective energy density of thin membranes of liquid crystal elastomers as the Gamma-limit of a widely used bulk model. These membranes can display fine-scale features both due to wrinkling that one expects in thin elastic…

Analysis of PDEs · Mathematics 2015-09-02 Pierluigi Cesana , Paul Plucinsky , Kaushik Bhattacharya
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