Figure 3: Collinear antiferromagnetic ordering.
From: Magnetic order in a frustrated two-dimensional atom lattice at a semiconductor surface
(a,b) Magnetic-order induced zone boundaries for the 
-Sn/Si(111) SBZ, (a) with 120° AF, (b) with CAF order in three-fold rotational superposition, leading to an effective 
SBZ. (c) Row-wise spin alignment of the CAF order. (d) Spectral weight transfer (see arrow) consistent with shadow bands induced by the CAF superstructure.
