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 light-based method to determine Berry curvature, a quantum property of electrons that has been difficult to access experimentally.

Berry curvature describes geometric features of the quantum-mechanical states of electrons. In condensed-matter physics, such properties can help researchers understand how electrons behave in materials and can be relevant to the study of electronic and optical effects in quantum systems.

The team measured the quantity in tungsten diselenide, a semiconductor examined in the form of a layer just one atom thick. Two-dimensional materials such as monolayer semiconductors are widely studied because their electronic properties can differ from those of bulk materials.

The measurement relied on ultrashort laser pulses, providing a new optical route for probing the quantum geometry of electrons. The researchers reported their findings in the latest issue of Nature Photonics.