Jose L. Lado

In a molecule resembling chlorophyll and built from carbon, a metal atom at the center acts as a toggle. Shifting it by fractions of a nanometer can make the molecule glow, quench, or boost its brightness a hundredfold.

Quantum spin chains resemble a line of people passing along a secret handshake: each turns to a neighbor, and how firmly they clasp palms determines how the wave runs through the entire chain. In the ideal Heisenberg chain, quantum magnetism’s bedrock, all handshakes are equal.

A parquet floor where every other plank is turned the opposite way looks symmetric. But if you run your hand over it, in one direction your fingers glide along the grain, and in the other they catch. That's roughly how the new type of magnetism studied in the crystal AgCrP2S6 works.