Spontaneous helix formation in non-chiral bent-core liquid crystals with fast linear electro-optic effect

Chiral symmetry breaking in bent-core liquid crystals.

By molecular modeling we demonstrate that the nematic long-range order discovered in bent-core liquid-crystal systems should reveal further spatially homogeneous phases. Two of them are identified as a tetrahedratic nematic (N_{T}) phase with D_{2d} symmetry and a chiral tetrahedratic nematic (N_{T};{ *}) phase with D2 symmetry. These phases were found for a lattice model with quadrupolar and o...

Electric field induced biaxiality and the electro-optic effect in a bent-core nematic liquid crystal

We report the observation of a biaxial nematic phase in a bent-core molecular system using polarizing microscopy, electro-optics, and dielectric spectroscopy, where we find that the biaxiality exists on a microscopic scale. An application of electric field induces a macroscopic biaxiality and in consequence gives rise to electro-optic switching. This electro-optic effect shows significant poten...

Converse flexoelectric effect in bent-core nematic liquid crystals.

We report on the converse flexoelectric effect in two bent-core nematic liquid crystals with opposite dielectric anisotropies. The results are based on electro-optic investigations of inplane field-driven distortions in homeotropic samples (the Helfrich method). They are interpreted by an extension of the Helfrich theory that takes into account the higher order distortions. The bend flexocoeffi...

Electro-optic technique to study biaxiality of liquid crystals with positive dielectric anisotropy: the case of a bent-core material.

We propose that, for materials having positive dielectric anisotropy, the biaxiality can be clearly verified or excluded by measuring the transmitted light intensity as a function of electric field. If the material is biaxial and is observed in homeotropically aligned cells, the schlieren texture should not disappear (transmitted intensity is not zero) even at very high fields, since the field ...

Electro-Optic Kerr Effect in Polymer-Stabilized Isotropic Liquid Crystals