How light changes matter: from a laser to a few photons

The properties of matter, e.g., the conductivity, can be tailored with light. This can be done with a lot of photons that are part of a laser beam, or in certain cases only a few photons are enough. In the theory department of the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, researchers use both extreme cases to investigate novel states of matter: a laser allows theoretically generating hitherto unobserved states of matter and via a few photons chemical reactions can be altered.