Imperfections reveal unexpected links between light and atomic vibrations in ultrathin boron nitride

First, one person stands up, followed by their neighbors, one after another, until a wave sweeps through the stadium. Atoms within a material move in a similar way: rather than remaining completely still in their positions, they vibrate together around their respective positions. In physics, these collective lattice vibrations are known as "phonons." Some of them can interact with light and change its energy in the process.