Phys.org has reported:

Researchers at Friedrich Schiller University Jena and the University of Regensburg have developed a light-based method to measure an electron property that has been difficult to access. They tested it in a semiconductor layer of tungsten diselenide only one atomic layer thick, using ultrashort laser pulses.

The property, called Berry curvature, describes geometric features of electrons’ quantum mechanical states. The results were published in the latest issue of the journal Nature Photonics.