To verify the status of the divergence K» term in the elastic theory of liquid crystals we study submicron films placed onto an isotropic fluid substrate in the Langmuir trough (Langmuir liquid crystal, LLC). The upper and lower surfaces favor normal and tangential molecular orientation, respectively. The periodic domain phase is observed in a nematic LLC. The dependence of the periodicity L of...

We predict the possible existence of a new phase of liquid crystals near the nematic-isotropic transition. This phase is an achiral, tilt analogue of the blue phase and is composed of a lattice of double-tilt, escape-configuration cylinders. We discuss the structure and the stability of this phase and provide an estimate of the lattice parameter.

A molecular theory of both elastic constants and the flexoelectric coefficients of bent-core nematic liquid crystals has been developed taking into account dipole-dipole interactions as well as polar interactions determined by the bent molecular shape. It has been shown that if polar interactions are neglected, the elastic constants are increasing monotonically with the decreasing temperature. ...

We report a significant role of side chains in the propagation of molecular orientation upon annealing the liquid crystal phase of polyfluorenes. Direct rubbing of poly(9,9-di(octyl)fluorene) led to the orientation of polymer segments in the top-most region of the film and enhanced propagation of this orientation along the rubbing direction was observed upon annealing. In contrast, the rubbing-...

We describe a simple method for determining anchoring energies from the measured optical response of liquid crystal cells. The method is quick and easy to use and can therefore be used to check a range of possible treatments, or for process control in an industrial environment .

We study experimentally the interaction of spatial optical solitons with curved dielectric surfaces in unbiased nematic liquid crystals. We demonstrate that this interaction depends on the curvature of the surface and the walk-off, and it can be employed for efficient routing and control of the soliton trajectories. We also observe a large-angle total internal reflection of the soliton beam fro...

We show that discotics, lying deep in the columnar phase, can exhibit an x-ray scattering pattern which mimics that of a somewhat unusual smectic liquid crystal. This exotic, new glassy phase of columnar liquid crystals, which we call a "hybrid columnar Bragg glass," can be achieved by confining a columnar liquid crystal in an anisotropic random environment of, e.g., strained aerogel. Long-rang...

We study the optical response of a metamaterial surface created by a lattice of split-ring resonators covered with a nematic liquid crystal and demonstrate millisecond timescale switching between electric and magnetic resonances of the metasurface. This is achieved due to a high sensitivity of liquid-crystal molecular reorientation to the symmetry of the metasurface as well as to the presence o...

The Hopf fibration is an example of a texture: a topologically stable, smooth, global configuration of a field. Here we demonstrate the controlled sculpting of the Hopf fibration in nematic liquid crystals through the control of point defects. We demonstrate how these are related to torons by use of a topological visualization technique derived from the Pontryagin-Thom construction.

2014 The free growth (at constant temperature) of a columnar hexagonal liquid crystal is described. The chosen material is the hexaoctyloxytriphenylene. Three growth regimes are observed depending upon the value of the supersaturation 0394: a petal-shape regime for 0394 0.2, a dendritic regime for 0.2 0394 0.6 and a dense branching regime for 0394 > 0.6. The first morphological transition ...