This "electric monopole" interaction ... A perfect sphere of charge would have zero dipole moment-- no matter what direction you apply the field in, you get the same total energy.

whose spin covers the entire sphere. To reconstruct the spin texture from the experiment, the researchers needed the electric and magnetic field vectors of the surface plasmon polaritons.

Ferroelectric materials have switchable polarization that can be controlled by an electric field, while stacking ... of a vector moving over a sphere. "For each stacking ferroelectric material ...