Breaking the ice rule: Barcelona physicists build an 'anti-spin ice' that does the opposite of ice

In ordinary ice, atoms follow a quiet rule about how they arrange themselves — and for decades that rule has organised a whole field of physics. A team including Pietro Tierno at the University of Barcelona has now built a system that breaks it on purpose. Using microscopic magnetic particles that attract rather than repel each other, and a rotating magnetic field to control them, the researchers created an 'anti-spin ice' in which the particles crowd together into patterns the ice rule forbids — even arranging themselves into a checkerboard of high charges. Published in Nature Communications, the work shows that frustration in materials can be switched and even programmed, a step toward designing new magnetic and computing materials.

SDG 9 · Industry, innovation and infrastructure — Mechanism: tech innovation