Submitted via IRC for SoyCow1984
'Topological materials' produce electron states that can be very interesting for technical applications, but it is extremely difficult to identify these materials and their associated electronic states. A 'crystal' made of light waves can now be used to deliberately drive the system out of equilibrium. By switching between simple and complicated states, the system reveals whether or not it has topologically interesting states.
Source: https://www.sciencedaily.com/releases/2018/12/181221123815.htm [sciencedaily.com]