In this material, the tiny magnets of vanadium atoms and electrons form something like a flock of birds. Each little magnet, like a bird, wants to fly its own way, but the electron flow forces them all to move in a single front, making the motion heavy and slow — electrons ‘gain weight’ hundreds of times over and become a thick liquid.

Compression to 10 gigapascals, the kind of pressure that turns graphite into diamond, cuts off this dance. Magnetic order and fluidity vanish simultaneously at the quantum transition point. Here it’s not temperature but quantum fluctuations that rule, and entropy (a measure of disorder) changes sharply. Spectroscopy can detect these transformations. Paradoxically, the most delicate behavior emerges in deep cold, when thermal noise quiets down.