Cholesteric liquid crystals, subject to externally applied magnetic fields and confined between two parallel planar surfaces with strong homeotropic anchoring conditions, are found to undergo transitions to different types of helicoidal configurations with disclinations. Analytical and numerical stu...

[Phys. Rev. E 100, 052703] Published Wed Nov 27, 2019

]]>We report experimental results of the orientational order parameter, the apparent tilt angle, and the field-induced tilt angle for three chiral smectic liquid crystalline materials investigated using infrared (IR) polarized spectroscopy. The common feature in these materials is use of the core 5-met...

[Phys. Rev. E 100, 052704] Published Wed Nov 27, 2019

]]>We present a Monte Carlo simulation study of chiral nematic liquid crystals confined in torus-shaped and cylindrical cavities. For an achiral nematic with planar degenerate anchoring confined to a toroidal or cylindrical cavity, the ground state is defect free, with an untwisted director field. As c...

[Phys. Rev. E 100, 052702] Published Mon Nov 25, 2019

]]>This paper presents a generalization of the elastic theory of anisotropic materials having nematic symmetry. The author shows that two families of heliconical distortions with opposite twists account for all uniform distortions of the nematic director that can fill three-dimensional space. An expression describing the twist-bend nematic phase is provided based on this generalized elastic theory.

[Phys. Rev. E 100, 052701] Published Fri Nov 15, 2019

]]>Weakly attractive interactions between the tips of rodlike colloidal particles affect their liquid-crystal phase behavior due to a subtle interplay between enthalpy and entropy. Here we employ molecular dynamics simulations on semiflexible, repulsive bead-spring chains where one of the two end beads...

[Phys. Rev. E 100, 042702] Published Mon Oct 07, 2019

]]>Molecular-statistical theory of rod-coil diblock copolymers is proposed using the general density functional approach which enables one to consider the cases of both weak and strong segregation. The free energy of the system is expressed as a functional of the phase-space densities of rod and coil m...

[Phys. Rev. E 100, 042701] Published Wed Oct 02, 2019

]]>We examine the ordering behavior of hard platelike particles in a very narrow, slitlike pore using the Parsons-Lee density functional theory and the restricted orientation approximation. We observe that the plates are orientationally ordered and align perpendicularly (face-on) to the walls at low de...

[Phys. Rev. E 100, 032704] Published Thu Sep 19, 2019

]]>We have described a novel mechanism of the kinklike pressure $\mathcal{P}(z-vt)$ response of the microsized twisted nematic volume under the effect of externally applied electric field $\mathbf{\text{E}}$ directed parallel to the restricted surfaces and induced by a strong local disturbance of the director field $\widehat{\mathbf{\text{n}}}$. It is found ...

[Phys. Rev. E 100, 032703] Published Tue Sep 17, 2019

]]>We investigate the optical properties of a metal-mirror microcavity containing a liquid-crystalline (LC) perylene tetracarboxylic bisimide (PTCBI) derivative. Measurements of the transmission's incidence angle dependence show that the peaks are split in a complex way and shift as the angle changes. ...

[Phys. Rev. E 100, 032701] Published Tue Sep 03, 2019

]]>We employ Monte Carlo simulations to study the defects occurring in a nematic droplet formed by biaxial molecules. The simulations are carried out using a lattice model based on a dispersive orientational biaxial potential previously employed to establish the rich phase diagram of the system. The fo...

[Phys. Rev. E 100, 032702] Published Tue Sep 03, 2019

]]>We conduct an in-depth analysis of the electroclinic effect in chiral, ferroelectric liquid crystal systems that have a first-order smectic-${A}^{*}$–smectic-${C}^{*}$ (Sm-${A}^{*}$–Sm-${C}^{*}$) transition, and show that such systems can be either type I or type II. In temperature-field parameter space type-I systems exhibit ...

[Phys. Rev. E 100, 022707] Published Thu Aug 29, 2019

]]>Bent-core (BC) molecules usually exhibit polar packing in smectic layers in which the long or bow axes tilt with respect to the layer normal. In many compounds, the tilt angle goes to zero, and typically the polarization (**P**) of neighboring layers has an antiferroelectric order ($\mathrm{Sm}A{P}_{\mathrm{AF}}$). A careful mo...

[Phys. Rev. E 100, 022706] Published Tue Aug 27, 2019

]]>Bulk-boundary correspondence is the emergence of features at the boundary of a material that are dependent on and yet distinct from the properties of the bulk of the material. The diverse applications of this idea in topological insulators as well as high energy physics prove its universality. Howev...

[Phys. Rev. E 100, 020702(R)] Published Mon Aug 26, 2019

]]>We explain theoretical peculiarities of the smectic-$A$–hexatic-$B$ equilibrium phase coexistence in a finite-temperature range recently observed experimentally in free-standing smectic films [I. A. Zaluzhnyy *et al.*, Phys. Rev. E **98**, 052703 (2018)]. We quantitatively describe this unexpected phenomenon...

[Phys. Rev. E 100, 022705] Published Mon Aug 26, 2019

]]>Molecular simulation is used to study the effect of molecular chirality on liquid crystalline phase transition and molecular assembly behavior. Based on a flexible chain (FCh) model with helical arrangement of side beads, the phase behavior of FCh models with various molecular chiralities are studie...

[Phys. Rev. E 100, 022703] Published Thu Aug 22, 2019

]]>While twist-bend nematic phases have been extensively studied, the experimental observation of two dimensional, oscillating splay-bend phases is recent. We consider two theoretical models that have been used to explain the formation of twist-bend phases—flexoelectricity and bond orientational order—...

[Phys. Rev. E 100, 022704] Published Thu Aug 22, 2019

]]>Instabilities in thin elastic sheets, such as wrinkles, are of broad interest both from a fundamental viewpoint and also because of their potential for engineering applications. Nematic liquid crystal elastomers offer a new form of control of these instabilities through direct coupling between micro...

[Phys. Rev. E 100, 022701] Published Tue Aug 13, 2019

]]>We employ a version of classical density functional theory to study the phase behavior of a simple model liquid crystal in an external field. The uniaxially symmetric molecules have a spherically symmetric core with superimposed orientation-dependent attractions. The interaction between the cores co...

[Phys. Rev. E 100, 022702] Published Tue Aug 13, 2019

]]>The ordering of 2D biaxial graphene oxide (GO) particles is investigated under the application of orthogonal electric (E) and magnetic fields (B); nematic, antinematic, or biaxial nematic ordering of GO particles is selectively obtained depending on the field conditions. Particularly, a perfect biax...

[Phys. Rev. E 100, 020701(R)] Published Mon Aug 12, 2019

]]>Using Monte Carlo numerical simulation, this work sketches the phase diagram of systems of certain hard ${C}_{2h}$-symmetric particles, formed by gluing two aligned and displaced hard spherocylinders with a cylindrical-length-to-diameter ratio realistically, if viewed not only from the lyotropic colloidal ...

[Phys. Rev. E 100, 012709] Published Tue Jul 30, 2019

]]>A simple model for estimating band edge wavelengths of selective reflection from cholesteric liquid crystals (CLCs) for oblique incidence is proposed. The proposed model and calculation method are based on a geometrical optics model and Bragg's law. Average refractive indices and Bragg angles in a C...

[Phys. Rev. E 100, 012708] Published Thu Jul 25, 2019

]]>Using grand-canonical Monte Carlo simulations, we investigate the phase diagram of hard rods of length $L$ with additional contact (sticky) attractions on square and cubic lattices. The phase diagram shows a competition between gas-liquid and ordering transitions (which are of demixing type on the squ...

[Phys. Rev. E 100, 012707] Published Mon Jul 22, 2019

]]>The unique nanometer-sized helical structure in $\mathrm{Sm}{C}_{\alpha}^{*}$ may sometimes evolve continuously to the micrometer-sized one in $\mathrm{Sm}{C}^{*}$; conceivably ferroelectric $\mathrm{Sm}{C}_{\alpha}^{*}$ is to be unwound by an applied electric field. By drawing electric-field-induced birefringence contours in the field-temperature phase diagram ...

[Phys. Rev. E 100, 010701(R)] Published Fri Jul 19, 2019

]]>Soft lamellar phases confined between two parallel plates and subject to a dilatative strain can become unstable exhibiting periodic deformations patterns of the layers. By a variational energy approach, a critical threshold for the imposed *finite* strain is derived in the case of *weak anchoring* cond...

[Phys. Rev. E 100, 012705] Published Tue Jul 16, 2019

]]>Most, but not all, liquid crystals tend to align when subject to shear flow, while most nematic polymeric liquid crystals undergo a tumbling instability, where the director rotates with the flow. The reasons of this instability remain elusive, as it is possible to find similar molecules exhibiting o...

[Phys. Rev. E 100, 012706] Published Tue Jul 16, 2019

]]>An elastic membrane with embedded nematic molecules is considered as a model of anisotropic fluid membrane with internal ordering. By considering the geometric coupling between director field and membrane curvature, the nematic texture is shown to induce anisotropic stresses additional to Canham-Hel...

[Phys. Rev. E 100, 012704] Published Mon Jul 15, 2019

]]>We study a dilute suspension of magnetic nanoparticles in a nematic-filled channel and how the spatial magnetization $\mathbf{M}$ can be tailored by the nematic anisotropy. We study the spatial configurations as stable critical points of a generalized phenomenological energy for a dilute ferronematic in the ab...

[Phys. Rev. E 100, 012703] Published Wed Jul 10, 2019

]]>We investigate how chiral dopants affect the chiral symmetry breaking of lyotropic chromonic liquid crystals (LCLCs) focusing on the double-twist (DT) director configurations in a cylindrical capillary. LCLCs of unusual elastic properties tend to exhibit chiral director configurations under confinem...

[Phys. Rev. E 100, 012702] Published Tue Jul 09, 2019

]]>It has been known that at high density, banana-shaped molecules are packed into a bent configuration locally, giving rise to interesting liquid-crystalline phases such as splay bend and twist bend. These spontaneous bend states can be modeled theoretically by allowing the bend elastic constant in th...

[Phys. Rev. E 100, 012701] Published Mon Jul 08, 2019

]]>The paper presents a detailed analysis of the effects of chiral doping on antiferroelectric ${B}_{2}$ subphases in bent core systems. The studied system exhibits the phase sequence $\text{Sm}A\leftrightarrow \text{Sm}A{P}_{A}\leftrightarrow \text{Sm}{C}_{S}{P}_{A}$. The chiral dopant induces the tilt in the $\text{Sm}A{P}_{A}$ phase or the tilt modulation in the $\text{Sm}{C}_{S}{P}_{A}$ phase, which is k...

[Phys. Rev. E 99, 062705] Published Wed Jun 26, 2019

]]>The heliconical twist-bend nematic (${N}_{\mathrm{TB}}$) phase is a promising candidate for novel electro-optic and photonic applications. However, the phase generally exists at elevated temperatures and across a narrow temperature interval, limiting its implementation in device fabrication, which would ideally req...

[Phys. Rev. E 99, 062704] Published Mon Jun 17, 2019

]]>The mean-field theory approach has been applied to the boomerang type particles from P. I. C. Teixeira, A. Masters, and B. Mulder [Mol. Cryst. Liq. Cryst. **323**, 167 (1998)] but with diminished strength of the interaction coefficient responsible for the coupling between molecular uniaxial and biaxial ...

[Phys. Rev. E 99, 062703] Published Wed Jun 12, 2019

]]>Freestanding smectic films give a unique possibility to study two-dimensional coalescence. We report experimental investigations in freestanding films and detailed analysis of coalescence of islands, circular regions of larger thickness than the surrounding film. The driving force of island coalesce...

[Phys. Rev. E 99, 062702] Published Tue Jun 11, 2019

]]>Supervised machine learning can be used to classify images with spatially correlated physical features. We demonstrate the concept by using the coordinate files generated from an off-lattice computer simulation of rodlike molecules confined in a square box as an example. Because of the geometric fru...

[Phys. Rev. E 99, 062701] Published Mon Jun 10, 2019

]]>We report a strategy to create photoswitchable chevron topographies via buckling of glassy nematic coatings with zigzag director alignments on soft elastic substrates. The idea is confirmed by numerical simulations where the nonlinear deformation of the coating is modeled by the Föppl–von Kármán pla...

[Phys. Rev. E 99, 052702] Published Fri May 31, 2019

]]>Results of broad-band dielectric spectroscopy studies in liquid crystal (pentylcyanobiphenyl, 5CB)-based nanocolloids are presented. They reveal the strong impact of ${\mathrm{BaTiO}}_{3}$ nanoparticles on dynamics and uniaxial ordering. Studies were carried out in an extreme range of temperatures ($\sim 150$ K), includi...

[Phys. Rev. E 99, 052703] Published Fri May 31, 2019

]]>In this paper, we model a number of both closed-packed and non-closed-packed crystals inside a cholesteric liquid crystal (LC) with different pitch values and nematic LC through the Landau–de Gennes free-energy method. We used binary boundary conditions (normal and planar anchoring) applied on the s...

[Phys. Rev. E 99, 052701] Published Mon May 13, 2019

]]>The theoretical description of the reorientational dynamics in the case of a hybrid-oriented two-dimensional (2D) liquid crystal (LC) cell, under the influence of a temperature gradient $\nabla T$, caused by a heat flux $\mathbf{\text{q}}$ directed at an angle $\alpha $ across the lower bounding surface with the orientational defect...

[Phys. Rev. E 99, 032701] Published Mon Mar 11, 2019

]]>We propose a surface energy for conically degenerate anchorings of uniaxial liquid crystal mesogens by modifying tensorial Nobili-Durand surface energy that is usually employed for fixed anchoring orientations with preferred polar angles. By minimizing Landau–de Gennes free energy and the proposed s...

[Phys. Rev. E 99, 032702] Published Mon Mar 11, 2019

]]>Chirality is an essential evolutionary-conserved physical aspect of swimming microorganisms. However, the role of chirality on the hydrodynamics of such microswimmers is still being elucidated. Hydrodynamic theories have so far predicted that, under a torque-free condition satisfied in the system of...

[Phys. Rev. E 99, 022704] Published Mon Feb 25, 2019

]]>Flow and director fields strongly couple with each other in liquid crystalline systems, and herein we discuss the coupling effect in cylindrical and spherical-cap droplets formed by nematic liquid crystal. Applying a temperature gradient to droplets dispersed in a liquid solvent, we observed a cross...

[Phys. Rev. E 99, 022702] Published Mon Feb 11, 2019

]]>We present a high accuracy Monte Carlo simulation study of the uniaxial nematic (${N}_{U}$) to isotropic ($I$) phase transition of a lattice dispersion model of uniaxial nematics composed of biaxial molecules. The ${N}_{U}\text{\u2212}I$ coexistence curve terminating at the Landau critical point has been determined using the m...

[Phys. Rev. E 99, 022703] Published Mon Feb 11, 2019

]]>We studied properties of monolayer films of $n$-cyanobiphenyl (with $n=5,...,8$) series of mesogens anchored on the surface of single walled boron nitride nanotube. In order to assess the impact of substrate polarization on the ordering effects we compare translational and reorientational dynamics of th...

[Phys. Rev. E 99, 022701] Published Thu Feb 07, 2019

]]>The bent-core liquid crystals (LCs) are highly regarded as the next-generation materials for electro-optic devices. The nematic (N) phase of these LCs possesses highly ordered smecticlike cybotactic clusters which are promising for electro-optic applications. We have studied a one-dimensional Landau...

[Phys. Rev. E 99, 012703] Published Mon Jan 28, 2019

]]>In this paper, we consider the optical properties of cholesteric liquid crystals (CLCs) with a dye. We investigate the reflection, transmission, and absorption spectra peculiarities. We show that in the presence of dye molecules, in certain conditions, the photonic band gap (PBG) splits into two, th...

[Phys. Rev. E 99, 012702] Published Fri Jan 25, 2019

]]>We report on the discovery of enormous negative viscosity in a nematic liquid crystal in the presence of turbulence induced by electric fields. As the negative viscosity in this system is so large, we are able to observe several phenomena originating from it. For example, we observe a spontaneous sh...

[Phys. Rev. E 99, 012701] Published Wed Jan 02, 2019

]]>We report experimental studies on the temperature-dependent translational and rotational viscosities of a few nematic liquid crystals made of highly polar molecules. Cyanobiphenyl (nCB) with longitudinal and cyanobicyclohexane molecules (CCN-mn) with transverse dipole moments were chosen and the mea...

[Phys. Rev. E 98, 062701] Published Wed Dec 19, 2018

]]>The minimal ingredient to generate a biaxial liquid-crystalline order is usually considered to be a strong biaxiality either in the molecular shape or in the molecular interactions. Although there is no fundamental reason to forbid a spontaneous biaxial liquid-crystalline ordering of pure uniaxial o...

[Phys. Rev. E 98, 050701(R)] Published Tue Nov 27, 2018

]]>Short pitch deformed helix ferroelectric liquid crystals have numerous applications as active materials in displays, optical telemetry, and biomedical devices. In this paper, we derive convenient analytical formulas to calculate the effective dielectric tensor of these materials beyond the space ave...

[Phys. Rev. E 98, 052707] Published Tue Nov 27, 2018

]]>The critical behavior at the transition from a uniform nematic to a twist-bend modulated nematic phase is revealed and shown to be well explained by the mean field approximation. The study was performed on a group of materials that exhibit an unusually broad temperature range of the nematic phase ab...

[Phys. Rev. E 98, 052706] Published Mon Nov 26, 2018

]]>Optical investigations and calculation of structures were performed on films of liquid crystal with the sequence of phase transitions in the bulk sample $\mathrm{Sm}{C}_{A}^{*}-\mathrm{Sm}{C}_{d3}^{*}-\mathrm{Sm}{C}_{d4}^{*}-\mathrm{Sm}{C}^{*}-\mathrm{Sm}{C}_{\alpha}^{*}-\mathrm{Sm}A-I$. We investigated freestanding nanofilms with number of smectic layers from 2 to 6 with thickness commensurate,...

[Phys. Rev. E 98, 052705] Published Tue Nov 20, 2018

]]>We study electrohydrodynamic convection (EHC) patterns in twisted nematic liquid crystal (TNCL) cells with an initial homeotropic alignment. In addition, we demonstrate switching characteristics due to the transition between the 90° and $-{90}^{\circ}$ twisted states. The pattern formations are similar to thos...

[Phys. Rev. E 98, 052704] Published Mon Nov 19, 2018

]]>Experimental and theoretical studies of a smectic-$A$–hexatic-$B$ transition in freely suspended films of thickness $2\u201310\phantom{\rule{3.33333pt}{0ex}}\mu \mathrm{m}$ of the $n$-pentyl-${4}^{\prime}-n$-pentanoyloxy-biphenyl-4-carboxylate (54COOBC) compound are presented. X-ray investigations revealed a discontinuous first-order transition into the hexatic phas...

[Phys. Rev. E 98, 052703] Published Fri Nov 16, 2018

]]>We use density functional theory to explore the stable adsorption geometries of the liquid crystal molecule 5CB on a graphene sheet. First, we calculate the dependence of the polarizability of 5CB on its geometry. Our results break down the contributions of the cyano, biphenyl, and alkyl groups to t...

[Phys. Rev. E 98, 052702] Published Tue Nov 06, 2018

]]>Azobenzene-based molecular systems are used as photoreswitchable smart materials with applications in many areas, including designing surface orientational patterning of anisotropic molecules. It is important and challenging to probe the real-time photoresponsive behaviors of these systems, particul...

[Phys. Rev. E 98, 052701] Published Fri Nov 02, 2018

]]>To inquire into whether two enantiomers can be absolutely distinguished on the sole basis of their different degrees of orientational ordering when dissolved in a chiral nematic liquid crystal, several enantiomeric pairs of hard helical particles are dissolved in a cholesteric (nematic) liquid cryst...

[Phys. Rev. E 98, 042704] Published Tue Oct 30, 2018

]]>We consider the influence of tetrahedral (octupolar) order on ferromagnetic nematic liquid-crystalline phases. The presence of tetrahedral order leads to broken parity symmetry in an achiral liquid-crystalline system, in addition to broken time-reversal symmetry associated with the existence of a sp...

[Phys. Rev. E 98, 042703] Published Thu Oct 25, 2018

]]>We study the light scattering by localized quasiplanar excitations of a cholesteric liquid crystal known as spherulites. We quantitatively evaluate the cross section of the axis rotation for polarized light by taking into account the anisotropic optical properties of the medium and the peculiar shap...

[Phys. Rev. E 98, 042702] Published Thu Oct 18, 2018

]]>Sunset Yellow (SSY) is an aromatic heterocycle nano-sheet functionalized by hydrophilic sulphanate groups. SSY forms chromonic stacks and liquid crystal (LC) phases in aqueous solution. The DNA oligomer 5′-GCGCTTAAGCGC-3′ is a self-complementary strand which forms duplexed B-form helices in aqueous ...

[Phys. Rev. E 98, 042701] Published Mon Oct 08, 2018

]]>A large number of smectic phases can have the same energy when short-range interlayer interactions (interaction of nearest layers and frustrating next-nearest layer interaction) are taken into account. In this situation even weak long-range interactions become important. They lift the degeneracy and...

[Phys. Rev. E 98, 032707] Published Fri Sep 28, 2018

]]>This article provides an explanation for the instability of toric focal conic domains and the stability of parabolic focal conic domains in the twist-bend nematic (${N}_{\mathrm{TB}}$) phase, by reason of the presence (the first case) or absence (the second case) of defect densities attached to the conics, which ar...

[Phys. Rev. E 98, 032705] Published Mon Sep 24, 2018

]]>Topological defects resulting from boundary constraints in confined liquid crystals have attracted extensive research interest. In this paper, we use numerical simulation to study the phase transition dynamics in the context of stochastic resonance in a bistable liquid crystal device containing defe...

[Phys. Rev. E 98, 032706] Published Mon Sep 24, 2018

]]>The Lehmann effect is the rotation of cholesteric droplets when they are submitted to a temperature gradient. So far, this effect was only observed in the coexistence region between the cholesteric phase and its isotropic liquid. This zone of coexistence is due to the presence in the LC of impuritie...

[Phys. Rev. E 98, 032704] Published Wed Sep 19, 2018

]]>The phase behavior of hard rectangular rods with edge lengths $L$, $D$, and $D$ is studied in a narrow slitlike pore using the Parsons-Lee density functional theory. Using the restricted orientation approximation, we find strong adsorption at the walls with planar ordering, second order uniaxial-biaxial o...

[Phys. Rev. E 98, 032703] Published Fri Sep 07, 2018

]]>We investigate flexodomains, which are observed in planar layers of certain nematic liquid crystals, when a dc voltage $U$ above a critical value ${U}_{c}$ is applied across the layer. They are characterized by stationary stripelike spatial variations of the director in the layer plane with a wave number $p(U...$

[Phys. Rev. E 98, 032702] Published Wed Sep 05, 2018

]]>In this study, we numerically investigate the interactions between pentagonal truncated pyramids in a nematic liquid crystal host. The colloidal arrangements are investigated by minimizing the Landau-de Gennes free energy in presence of homeotropic anchoring surface energy upon the particles. We fur...

[Phys. Rev. E 98, 032701] Published Tue Sep 04, 2018

]]>The dielectric spectra of the twist bend nematic phase (${N}_{\mathrm{TB}}$) of an achiral asymmetric bent-core liquid crystalline compound are studied for determining the various relaxation modes. Dielectric measurements are also carried out under the bias field $E$ up to 8 V/µm. Two molecular and two collective rel...

[Phys. Rev. E 98, 022704] Published Fri Aug 31, 2018

]]>Electrokinetic phenomena in a nematic suspension are considered when one or more dielectric particles are suspended in a liquid crystal matrix in its nematic phase. The long-range orientational order of the nematic constitutes a fluid with anisotropic properties. This anisotropy enables charge separ...

[Phys. Rev. E 98, 022703] Published Thu Aug 23, 2018

]]>In the present work, we have studied the liquid crystalline properties of a luminescent molecule, which presents smectic mesophases, using the emission ellipsometry technique. A methodology with photoselection of the excitation light to improve the experiment is presented. An empirical model is prop...

[Phys. Rev. E 98, 022702] Published Fri Aug 10, 2018

]]>A rigorous microscopic treatment of a nematic fluid system based on a pairwise interaction potential is immensely complex. For studying such systems molecular field theories are often the standard method of choice. In this paper we have chosen a simple effective potential $U=\frac{{u}_{4}}{{v}^{4}}-\frac{{u}_{2}}{{v}^{2}}-\frac{A{u}_{2}}{{v}^{2}}\u2329{P}_{2}\u232a{P}_{2}(cos\vartheta )$...

[Phys. Rev. E 98, 022701] Published Wed Aug 01, 2018

]]>Electric field driven Frèedericksz transition in chiral nematic (cholesteric) planar liquid crystal cell is studied in the presence of flexoelectric effect. An inhomogeneity of electric field and finiteness of anchoring energy are considered. The extra contribution to the electric field induced by f...

[Phys. Rev. E 98, 012702] Published Mon Jul 23, 2018

]]>When a material surface is functionalized so as to acquire some type of order, functionalization of which soft condensed matter systems have recently provided many interesting examples, the modeler faces an alternative. Either the order is described on the curved, physical surface where it belongs, ...

[Phys. Rev. E 98, 012701] Published Fri Jul 20, 2018

]]>An anomalous dielectric relaxation process, called the partially unwound helical mode (*p-*UHM), is a collective dielectric process apart from the well known Goldstone and soft mode process; it is studied in the smectic ${C}^{*}$ ($\mathrm{Sm}\text{\u2212}{C}^{*}$) phase and at the transition temperature of the $\mathrm{Sm}\text{\u2212}{C}^{*}-\mathrm{Sm}\text{\u2212}{A}^{*}$ phase in the...

[Phys. Rev. E 97, 062707] Published Wed Jun 27, 2018

]]>When chiral liquid crystals or magnets are subjected to applied fields or other anisotropic environments, the competition between favored twist and anisotropy leads to the formation of complex defect structures. In some cases, the defects are skyrmions, which have ${180}^{\circ}$ double twist going outward fro...

[Phys. Rev. E 97, 062706] Published Wed Jun 20, 2018

]]>We consider the reshaping of closed Janus filaments acquiring intrinsic curvature upon actuation of a driven component—a nematic elastomer elongating upon phase transition. Linear stability analysis establishes instability thresholds of circles with no imposed twist, dependent on the ratio $q$ of the ...

[Phys. Rev. E 97, 062705] Published Mon Jun 18, 2018

]]>We modeled the experimentally observed self-assembly of nanoparticles (NPs) into shells with diameters up to 10 $\mu \mathrm{m}$, via segregation from growing nematic domains. Using field-based Monte Carlo simulations, we found the equilibrium configurations of the system by minimizing a free-energy functional th...

[Phys. Rev. E 97, 062704] Published Fri Jun 15, 2018

]]>The self-propelled motions of micron-sized nematic liquid crystal droplets in an aqueous surfactant solution have been studied by tracking individual droplets over long time periods. Switching between self-propelled modes is observed as the droplet size decreases at a nearly constant dissolution rat...

[Phys. Rev. E 97, 062703] Published Thu Jun 14, 2018

]]>Using resonant x-ray scattering techniques, transitional subphases during the electric-field-induced phase transition of a mixture of Se-containing chiral liquid crystals, 80% AS657 and 20% AS620, in a planar-aligned cell geometry were investigated, where the prototypical phase sequence $\mathrm{Sm}{C}_{A}^{*}-\mathrm{Sm}{C}_{\gamma}^{*}-\mathrm{...}$

[Phys. Rev. E 97, 062702] Published Tue Jun 12, 2018

]]>We develop a theoretical model to describe two-beam energy exchange in a hybrid photorefractive cholesteric cell with a short-pitch helix oriented parallel to the cell substrates (so-called uniformly lying helix configuration). Weak and strong light beams incident on the hybrid cell interfere and in...

[Phys. Rev. E 97, 062701] Published Fri Jun 01, 2018

]]>When a spatially uniform system that displays a liquid-crystal ordering on a two-dimensional surface is confined inside a rectangular box, the liquid crystal direction field develops inhomogeneous textures accompanied by topological defects because of the geometric frustrations. We show that the ric...

[Phys. Rev. E 97, 052707] Published Wed May 30, 2018

]]>Ordering configurations of a director field on a curved membrane induces stress. In this work, we present a theoretical framework to calculate the stress tensor and the torque as a consequence of the nematic ordering; we use the variational principle and invariance of the energy under Euclidean moti...

[Phys. Rev. E 97, 052706] Published Tue May 29, 2018

]]>Nematic films are thin fluid structures, ideally two dimensional, endowed with an in-plane degenerate nematic order. In this paper we examine a generalization of the classical Plateau problem to an axisymmetric nematic film bounded by two coaxial parallel rings. At equilibrium, the shape of the nema...

[Phys. Rev. E 97, 052705] Published Thu May 24, 2018

]]>Nematogenic liquids are materials that are in high demand for many application purposes. Field-induced nematic order in isotropic liquids can be observed by the enhancement of electric permittivity during dielectric spectroscopy measurements under the bias electric field. For this reason, dielectric...

[Phys. Rev. E 97, 052704] Published Fri May 18, 2018

]]>We formulate the scaled particle theory for a general mixture of hard isosceles triangles and calculate different phase diagrams for the one-component fluid and for certain binary mixtures. The fluid of hard triangles exhibits a complex phase behavior: (i) the presence of a triatic phase with sixfol...

[Phys. Rev. E 97, 052703] Published Fri May 11, 2018

]]>The hexatic phase predicted by the theories of two-dimensional melting is characterized by the power-law decay of the orientational correlations, whereas the in-layer bond orientational order in all the hexatic smectic phases observed so far was found to be long range. We report a hexatic smectic ph...

[Phys. Rev. E 97, 052702] Published Thu May 10, 2018

]]>Active colloids and liquid crystals are capable of locally converting the macroscopically supplied energy into directional motion and promise a host of new applications, ranging from drug delivery to cargo transport at the mesoscale. Here we uncover how topological solitons in liquid crystals can lo...

[Phys. Rev. E 97, 052701] Published Wed May 02, 2018

]]>We investigate the alternating current (ac) -driven electroconvection (EC) in one-dimensional cells (1DCs) under the in-plane switching mode. In 1DCs, defect-free EC can be realized. In the presence and absence of external multiplicative noise, the features of traveling waves (TWs), such as their Ho...

[Phys. Rev. E 97, 042707] Published Mon Apr 30, 2018

]]>A molecular field theory and coarse-grained computer simulations with dissipative particle dynamics have been used to study the spontaneous orientational ordering of anisotropic nanoparticles in the lamellar and hexagonal phases of diblock copolymers and the effect of nanoparticles on the phase beha...

[Phys. Rev. E 97, 042706] Published Fri Apr 27, 2018

]]>We investigate the effects of flow on the dynamics of ferromagnetic nematic liquid crystals. As a model, we study the coupled dynamics of the magnetization, $\mathbf{M}$, the director field, $\mathbf{n}$, associated with the liquid crystalline orientational order, and the velocity field, $\mathbf{v}$. We evaluate how simple shear f...

[Phys. Rev. E 97, 042705] Published Thu Apr 26, 2018

]]>Knotted fields enrich a variety of physical phenomena, ranging from fluid flows, electromagnetic fields, to textures of ordered media. Maxwell's electrostatic equations, whose vacuum solution is mathematically known as a harmonic field, provide an ideal setting to explore the role of domain topology...

[Phys. Rev. E 97, 040702(R)] Published Wed Apr 25, 2018

]]>Chiral smectic liquid crystals are known for their huge optical activity due to the precession of the anisotropic dielectric tensor around the helicoidal axis. For an oblique direction of the propagating wave, the helix acts as a grating which splits an incident beam in different directions as long ...

[Phys. Rev. E 97, 042704] Published Wed Apr 25, 2018

]]>We use experiment and computational modeling to understand the defect structure and director configuration in a nematic liquid crystal capillary bridge confined between two parallel plates. We find that tuning of the aspect ratio of the bridge drives a transition between a ring defect and a point de...

[Phys. Rev. E 97, 040701(R)] Published Fri Apr 13, 2018

]]>Tilted smectic liquid crystal phases such as the smectic-C phase seen in calamitic liquid crystals are usually treated using the assumption of biaxial orthorhombic symmetry. However, the smectic-C phase has monoclinic symmetry, thereby allowing disassociation of the principal optic and dielectric ax...

[Phys. Rev. E 97, 042702] Published Tue Apr 10, 2018

]]>A biaxial surface potential ${\mathrm{\Phi}}_{s}$ of smectic-${C}^{*}$ surface-stabilized ferroelectric liquid crystals (SSFLCs) is introduced in this paper to explain the experimentally observed electric-field dependence of polarization ${\stackrel{\u0303}{P}}_{\mathrm{cell}}\left(E\right)$, in particular the shape of the static hysteresis loops. Our potential consist...

[Phys. Rev. E 97, 042703] Published Tue Apr 10, 2018

]]>We study experimentally the impact of spherical nanoparticles on the orientational order parameters of a host nematic liquid crystal. We use spherical core-shell quantum dots that are surface functionalized to promote homeotropic anchoring on their interface with the liquid crystal host. We show exp...

[Phys. Rev. E 97, 042701] Published Fri Apr 06, 2018

]]>In thermotropic chiral $\mathrm{Sm}\text{\u2212}{A}^{*}$ phases, an electric field along the smectic layers breaks the ${D}_{\infty}$ symmetry of the $\mathrm{Sm}\text{\u2212}{A}^{*}$ phase and induces a tilt of the liquid crystal director. This so-called electroclinic effect (ECE) was first reported by Garoff and Meyer in 1977 and attracted substantial scientific a...

[Phys. Rev. E 97, 032705] Published Fri Mar 30, 2018

]]>The interaction between nematic liquid crystals and polymer-coated substrates may lead to slow reorientation of the easy axis (so-called “director gliding”) when a prolonged external field is applied. We consider the experimental evidence of zenithal gliding observed by Joly *et al.* [Phys. Rev. E **70**,...

[Phys. Rev. E 97, 032704] Published Mon Mar 19, 2018

]]>The competing effect of surface anchoring of dispersed microparticles and elasticity of nematic and cholesteric liquid crystals has been shown to stabilize a variety of topological defects. Here we study a pair of colloidal microparticles with homeotropic and planar surface anchoring across $N\text{\u2212}\mathrm{Sm}A\text{\u2212}\mathrm{Sm}\mathrm{...}$

[Phys. Rev. E 97, 032702] Published Tue Mar 13, 2018

]]>Coupling between the defect mode of a cholesteric liquid crystal and the localized mode of a cholesteric liquid crystal–phase plate–metal structure is theoretically demonstrated. It is shown that the transmittance spectrum can be tuned by changing the twist-defect angle and helix pitch, which are go...

[Phys. Rev. E 97, 032703] Published Tue Mar 13, 2018

]]>A micrometer-scale elastic shell immersed in a nematic liquid crystal may be deformed by the host if the cost of deformation is comparable to the cost of elastic deformation of the nematic. Moreover, such inclusions interact and form chains due to quadrupolar distortions induced in the host. A conti...

[Phys. Rev. E 97, 032701] Published Fri Mar 02, 2018

]]>