Mladen Horvatić

A handful of copper coins scattered on a triangular grid freezes into a strange order when a current is passed through them. That's roughly how tiny magnetic arrows, electron spins, behave in a crystal with the rare name Y-capellasite.

A magnetic field of 42 tesla — about a million times stronger than Earth's field. In such a field, the crystal SrCu₂(BO₃)₂ behaves unusually: its magnetization doesn't increase smoothly but in jumps, pausing at specific values.