Chaoyu Chen

A doctor stares at a gray-white smudge on the screen. It's the face of an unborn child. One shadow in the right place, and you can plan surgery in time. But not everyone sees that shadow: cleft lip or palate is rare, and a young specialist might go years without ever spotting one.

A crystal of osmium dioxide, OsO₂, is like a stubborn teenager: under ordinary conditions it behaves like a typical metal, but press hard enough and its character changes.

In the crystal Rb1-xV2Te2O, the spins of vanadium atoms arrange in a checkerboard pattern: each spin is surrounded by opposite spins. This pattern is called G-type antiferromagnetism. Neutrons passing through the sample scatter off this pattern and reveal its geometry, like light from a flashlight shining through blinds casting stripes on a wall.