Apolar Anchoring and Electrostatic Control of Domain Formation in Ferroelectric Nematic Liquid Crystals

Ferroelectric nematic liquid crystals are formed by polar molecules and exhibit domain patterns determined by anchoring conditions and long-range electrostatic interactions. When confined to thin cells with photopatterned, bidirectional apolar anchoring, striped domains emerge with alternating left- and right-handed twists of polarization along the normal to the cell. A photoaligned +1-radial defect splits into sectors ("pizza slices") with a splay of polarization. In thin cells, the polarization alternates from pointing inward and outward the +1 core but does not change along the normal to the cell. In thick cells, the polarization within each sector twists along the normal to the cell, so that the top and bottom polarizations are antiparallel. The physical mechanisms driving the twist and alternating splay patterns are attributed to the reduction of the electrostatic energy.