Magnetic oscillation modes in square lattice artificial spin ice, Lasnier and Wysin

Modes that are antisymmetric across the vertex:
A-minus A-plus

Modes that are symmetric across the vertex:
S-minus S-plus

Solid blue arrows have positive z-components. Open red arrows have negative z-components.
These animations do not correctly represent the relative frequencies, only the phase relationships among the oscillation components on the sublattices.