Ferroelectric nematic liquids with conics

Spontaneous electric polarization of solid ferroelectrics follows aligning directions of crystallographic axes. Domains of differently oriented polarization are separated by domain walls (DWs), which are predominantly flat and run along directions dictated by the bulk translational order and the sample surfaces. Here we explore DWs in a ferroelectric nematic (N-F) liquid crystal, which is a fluid with polar long-range orientational order but no crystallographic axes nor facets. We demonstrate that DWs in the absence of bulk and surface aligning axes are shaped as conic sections. The conics bisect the angle between two neighboring polarization fields to avoid electric charges. The remarkable bisecting properties of conic sections, known for millennia, play a central role as intrinsic features of liquid ferroelectrics. The findings could be helpful in designing patterns of electric polarization and space charge.

Automated summary

Solid ferroelectrics have aligned polarization along crystallographic axes, with different polarization domains separated by flat domain walls. In a ferroelectric nematic liquid crystal without crystallographic axes or facets, domain walls shape as conic sections to bisect the angle between neighboring polarization fields and avoid electric charges. The intrinsic properties of conic sections play a central role in liquid ferroelectrics.