The principle "Work smarter, not harder!" apparently also applies to controlling quantum materials with light. Many of their fascinating properties depend on how the atoms are arranged in the crystal. Ultrashort laser pulses can be used to alter these structures in a targeted way—the light first e xcites electrons, whose changed energy and dynamics exert forces on the atomic nuclei and can thereby set the atoms in motion. Such processes unfold within femtoseconds, a millionth of a billionth of a second. ...read more read less