Magnetic monopoles double-layer in spin ice (Dr Jaubert Ludovic)

Representation of double-layer magnetic monopoles in spin ice with arrows pointing from south to north poles. The green layers are made of south monopoles, while the yellow layers represent north monopoles. Jaubert’s team predicted the presence of a stable double-layer structure in spin ice at low temperatures (close to zero Kelvin). The double layer is formed by 2 layers of north  magnetic charges in yellow and 2 layers of south magnetic charges in green. The spins of the spin ice naturally tend towards the configurations that require less energy and that are more stable: two spins of the tetrahedron point towards the center and two point outward (2 in - 2 out). A magnetic monopole is generated when a disturbance causes a spin to flip its orientation (3 in - 1 out or 1 in - 3 out). The 3 in - 1 out configuration makes a north magnetic monopole, while the opposite forms a south magnetic monopole.