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Related papers: Sawtooth profile in smectic A liquid crystals

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If a surface stabilized ferroelectric liquid crystal cell is cooled from the smectic-A to the smectic-C phase, its layers thin causing V-shaped (chevron like) defects to form. These create an energy barrier that can prevent switching…

Analysis of PDEs · Mathematics 2016-11-14 Lidia Mrad , Daniel Phillips

The Landau-de Gennes model of liquid crystals is a functional acting on wave functions (order parameters) and vector fields (director fields). In a specific asymptotic limit of the physical parameters, we construct critical points such that…

Analysis of PDEs · Mathematics 2016-02-22 Só ren Fournais , Ayman Kachmar , Xing-Bin Pan

We analytically derive the effective layer elastic energy of smectic-A and smectic-C liquid crystals by adiabatic elimination of the orientational degree of freedom from the generalized Chen-Lubensky model. In the smectic-A phase, the…

Soft Condensed Matter · Physics 2007-11-13 Hiroto Ogawa

A phenomenological free energy model is proposed to describe the behavior of smectic liquid crystals, an intermediate phase that exhibits orientational order and layering at the molecular scale. Advantageous properties render the functional…

Soft Condensed Matter · Physics 2021-05-05 Jingmin Xia , Scott MacLachlan , Timothy J. Atherton , Patrick E. Farrell

Structural studies by synchrotron x-ray diffraction on two main-chain smectic-C elastomers reveal the presence of two different relaxation mechanisms in these systems at low and high strains. At low strains, the smectic layers are…

Soft Condensed Matter · Physics 2014-09-19 Sonal Dey

We mathematically model Smectic-A (SmA) phases with a modified Landau-de Gennes (mLdG) model. The orientational order of the SmA phase is described by a tensor-order parameter $\mathbf{Q}$, and the positional order is described by a real…

Soft Condensed Matter · Physics 2025-09-22 Baoming Shi , Yucen Han , Chengdi Ma , Apala Majumdar , Lei Zhang

Based on simplifications of previous numerical calculations [Graf and L\"{o}wen, Phys. Rev. E \textbf{59}, 1932 (1999)], we propose algebraic free energy expressions for the smectic-A liquid crystal phase and the crystal phases of hard…

Soft Condensed Matter · Physics 2020-07-08 V. F. D. Peters , M. Vis , H. H. Wensink , R. Tuinier

A Landau-de Gennes model that integrates the nematic quadrupolar tensor order parameter and complex smectic-A order parameters is used to simulate the two-dimensional growth of an initially homogeneous smectic-A spherulite in an isotropic…

Soft Condensed Matter · Physics 2009-02-11 Nasser Mohieddin Abukhdeir , Alejandro D. Rey

We present a detailed analysis of the molecular packing of a strained liquid crystal elastomer composed of chiral mesogens in the smectic A phase. X-ray diffraction patterns of the elastomer collected over a range of orientations with…

The magnetic structure of Ba_2CuGe_2O_7 is investigated by neutron diffraction in magnetic fields applied along several directions in the $(a,b)$ plane of the crystal. In relatively weak fields, $H\lesssim 0.5$~T, the propagation vector of…

Condensed Matter · Physics 2009-10-30 A. Zheludev , S. Maslov , G. Shirane , Y. Sasago , N. Koide , K. Uchinokura , D. A. Tennant , S. E. Nagler

The de Gennes free energy functional of an infinite smectic-A liquid crystal at the dual point is shown to be topological and to depend only on the number of screw dislocations and the anisotropy. This result generalizes the existence of a…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Eric Akkermans , Sankalpa Ghosh , Amos Schtalheim

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

We study a new mechanism of active matter confinement of a thin, active nematic sample consisting of microtubules, activated by Adenosine Triphosphate (ATP), placed between a slab of passive liquid crystal, the compound 8CB, and water. The…

Soft Condensed Matter · Physics 2024-07-03 M. Carme Calderer , Lingxing Yao , Longhua Zhao , Dmitry Golovaty , Jordi Ignés-Mullol , Francesc Sagués

We develop a theory of Smectic A - Smectic C phase transition with anomalously weak smectic layer contraction. We construct a phenomenological description of this transition by generalizing the Chen-Lubensky model. Using a mean-field…

Soft Condensed Matter · Physics 2009-11-13 M. V. Gorkunov , M. A. Osipov , F. Giesselmann , T. J. Sluckin , J. P. F. Lagerwall

We consider a theoretical model for the chiral smectic A twisted ribbons observed in assemblies of fd viruses condensed by depletion forces. The depletion interaction is modeled by an edge energy assumed to be proportional to the depletant…

Soft Condensed Matter · Physics 2010-08-12 C. Nadir Kaplan , Hao Tu , Robert A. Pelcovits , Robert B. Meyer

Ginzburg-Landau-de Gennes -type covariant theories are extensively used in connection with twist grain boundary (TGB) phases of chiral smectogens. We analyze the stability conditions for the linear, covariant elasticity theory of smectic-C…

Soft Condensed Matter · Physics 2013-03-05 P. R. Venkatramanan , Yashodhan Hatwalne , N. V. Madhusudana

The single ion properties of the zig-zag chain compound SrTm$_2$O$_4$ have been investigated using heat capacity, magnetic susceptibility, magnetization, inelastic neutron scattering, and polarized muon spectroscopy. Two crystal field…

In this paper we are interested in the Landau-de Gennes functional introduced to study the transition between the smectic and nematic phases of a liquid crystal. We define a reduced functional by constraining the director field to satisfy a…

Mathematical Physics · Physics 2009-06-04 Nicolas Raymond

In this paper, we present energy-stable numerical schemes for a Smectic-A liquid crystal model. This model involve the hydrodynamic velocity-pressure macroscopic variables $({\bf u},p)$ and the microscopic order parameter of Smectic-A…

Numerical Analysis · Mathematics 2015-06-23 Francisco Guillén-González , Giordano Tierra

Smectic liquid crystals can be viewed as model systems for lamellar structures for which there has been extensive theoretical development. We demonstrate that a nonlinear energy description is required with respect to the usual Landau-de…

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