Fig. 8
Chain particles with conic anchoring and their elastic multipole moments. a The defects transitions from Saturn ring on the equator (homeotropic anchoring) to combination of both Saturn rings, neck defects and boojums (moderate angle α) and ultimately to combination of neck defects and boojums (planar anchoring). The surface anchoring tilt angle notably affects n(r)-distortions around the particle and consequently its multipole moment. b Chain composites have mirror symmetry along z-axis, therefore multipole moments with odd l are not present. a Circles show configurations and b parameter space also realized in the experiments (see Fig. 7). Rhombs show a configurations and b parameter space with pure multipoles. Strong quadrupole emerges for spheres with tangential or homeotropic anchoring on the surface (marked respectively by red and green rhombs). Sphere with conic anchoring angle α = 40° express dominant hexadecapole (marked by a blue rhomb) since the quadrupole and other multipoles are absent. The hexadecapolar moment is also dominant in particles comprising of two spheres with tangential anchoring (marked by a red circle). 64-Pole is weak, but for the particle comprising of three spheres it is the most prominent multipole (marked by a green circle)
