Ultrashort laser pulses offer a new way to probe electrons' quantum geometry

Researchers at Friedrich Schiller University Jena and the University of Regensburg have developed a method for determining, using light, a quantum property of electrons that has hitherto been difficult to access. The focus is on what is known as Berry curvature—a quantity that describes certain geometric properties of the quantum mechanical states of electrons. The researchers measured it in a layer of the semiconductor tungsten diselenide, just one atomic layer thick, using ultrashort laser pulses. The results have been published in the latest issue of the journal Nature Photonics.