Magnetic Coulomb phase in spin ice

Analysis of a Fully Packed Loop Model Arising in a Magnetic Coulomb Phase.
L. D. C. Jaubert, M. Haque, and R. Moessner
Phys. Rev. Lett. 107, 177202 (2011)

Left: Loops of two colors, blue (red) for up (down) spins, and a worm (dashed green, made of alternating up and down spins), on the checkerboard lattice. Right: Spin ice model on the pyrochlore lattice with in (blue) and out (red) spins.