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Nematic liquid crystals exhibit configurations in which the underlying ordering changes markedly on macroscopic length scales. Such structures include topological defects in the nematic phase and tactoids within nematic-isotropic…

Soft Condensed Matter · Physics 2020-05-01 Cody D. Schimming , Jorge Viñals

The properties of liquid crystals can be modelled using an order parameter which describes the variability of the local orientation of rod-like molecules. Defects in the director field can arise due to external factors such as applied…

Numerical Analysis · Mathematics 2019-10-08 Craig S. MacDonald , John A. Mackenzie , Alison Ramage

We characterise the particlelike kinematics of charge-carrying topological defects in nematic media via a geometric field theory. This differs from the theory of electromagnetism, with which it is often compared, due to the absence of…

Soft Condensed Matter · Physics 2026-05-22 Joseph Pollard , Richard G. Morris

To enhance the understanding of the behavior of active nematic, it is important to understand the behavior of topological defects. In this paper, we study the configuration of topological defects of a two-dimensional active nematic around a…

Soft Condensed Matter · Physics 2026-02-16 Hiroki Matsukiyo , Jun-ichi Fukuda

The ground state of twist-bend nematic liquid crystals is a heliconical molecular arrangement in which the nematic director precesses uniformly about an axis, making a fixed angle with it. Both precession senses are allowed in the ground…

Soft Condensed Matter · Physics 2014-04-15 Epifanio G. Virga

Computer simulations are presented of the isotropic-to-nematic transition in a liquid crystal confined between two parallel plates a distance H apart. The plates are neutral and do not impose any anchoring on the particles. Depending on the…

Statistical Mechanics · Physics 2010-08-20 J. M. Fish , R. L. C. Vink

A two-dimensional or quasi-two-dimensional nematic liquid crystal refers to a surface confined system. When such a system is further confined by external line boundaries or excluded from internal line boundaries, the nematic directors form…

Soft Condensed Matter · Physics 2022-04-27 Xiaomei Yao , Lei Zhang , Jeff Z. Y. Chen

Topological defects in active liquid crystals can be confined by introducing gradients of activity. Here, we examine the dynamical behavior of two defects confined by a sharp gradient of activity that separates an active circular region and…

Soft Condensed Matter · Physics 2021-06-16 Ali Mozaffari , Rui Zhang , Noe Atzin , Juan J. de Pablo

The growing interest in active nematics and the emerging evidence of the relevance of topological defects in biology asks for reliable data analysis tools to identify, classify and track such defects in simulation and microscopy data. We…

Soft Condensed Matter · Physics 2020-02-10 Dennis Wenzel , Michael Nestler , Sebastian Reuther , Maximilian Simon , Axel Voigt

We study the topology of smectic defects in two and three dimensions. We give a topological classification of smectic point defects and disclination lines in three dimensions. In addition we describe the combination rules for smectic point…

Soft Condensed Matter · Physics 2019-11-19 Thomas Machon , Hillel Aharoni , Yichen Hu , Randall D. Kamien

We analyze the phase behavior of lyotropic nematic liquid crystals in the self-organizing flow, viz. so called active nematics (AN). Their elastic properties are mutually caused by evolution of topological defects (for instance,…

Soft Condensed Matter · Physics 2018-02-20 L. V. Elnikova

We show by means of continuum theory and simulations that geometric percolation in uniaxial nematics of hard slender particles is fundamentally different from that in isotropic dispersions. In the nematic, percolation depends only very…

Soft Condensed Matter · Physics 2019-03-07 Shari P. Finner , Tanja Schilling , Paul van der Schoot

Liquid crystals have attracted enormous interest because of the variety of their phases and richness of their application. The interplay of general physical symmetries and specific molecular features generates a myriad of different…

Statistical Mechanics · Physics 2011-09-06 Marco G. Mazza , Martin Schoen

Using particle-resolved molecular-dynamics simulations, we compute the phase diagram for soft repulsive spherocylinders confined on the surface of a sphere. While crystal (K), smectic (Sm), and isotropic (I) phases exhibit a stability…

Soft Condensed Matter · Physics 2025-11-03 Jaydeep Mandal , Hartmut Löwen , Prabal K. Maiti

A simple model is proposed for nematogenic molecules that favor perpendicular orientations as well as parallel ones. (Charged rods, for example, show this antagonistic tendency.) When a small disorienting field is applied along $z$, a low…

Soft Condensed Matter · Physics 2009-11-10 T. G. Sokolovska , M. E. Cates , R. O. Sokolovskii

Nematic liquid crystals possess three different phases: isotropic, uniaxial, and biaxial. The ground state of most nematics is either isotropic or uniaxial, depending on the external temperature. Nevertheless, biaxial domains have been…

Soft Condensed Matter · Physics 2009-11-11 Paolo Biscari , Gaetano Napoli , Stefano Turzi

In the Landau-de Gennes theoretical framework of a $Q -tensor description of nematic liquid crystals, we consider a radial hedgehog defect with strong anchoring conditions in a ball $B \subset \mathbb{R}^3$ . We show that the scalar order…

Analysis of PDEs · Mathematics 2013-09-19 Xavier Lamy

Crystallization of supersaturated liquids usually starts by heterogeneous nucleation. Mounting evidence shows that even homogeneous nucleation in simple liquids takes place in two steps; first a dense amorphous precursor forms, and the…

Materials Science · Physics 2014-07-15 László Gránásy , Frigyes Podmaniczky , Gyula I. Tóth , György Tegze , Tamás Pusztai

Liquid crystalline phases of matter permeate nature and technology, with examples ranging from cell membranes to liquid-crystal displays. Remarkably, electronic liquid crystal phases can exist in two-dimensional electron systems (2DES) at…

Mesoscale and Nanoscale Physics · Physics 2017-11-20 Q. Qian , J. Nakamura , S. Fallahi , G. C. Gardner , M. J. Manfra

Defect dynamics in a thin active nematic layer is studied by asymptotic matching of solutions in the defect core and the far field. The analysis is facilitated by the correspondence between the 2D nematic and complex scalar field models.…

Soft Condensed Matter · Physics 2015-06-16 L. M. Pismen