When a metal’s atomic lattice contains some disorder, the conduction electrons can become trapped in small regions—a phenomenon called Anderson localization. The effect is strongest in 1D and 2D crystals, where even weak disorder leads to localization. Given the potential importance of graphene and other 2D materials for future electronics, researchers want to verify and extend the theory for 2D localization. Now Abhay Pasupathy of Columbia University and his colleagues have directly observed the onset of localization by using scanning tunneling spectroscopy (STS)—which uses a scanning tunneling microscopy (STM) probe—to study 3D samples having progressively fewer layers until they become 2D [1].
To read more, click here.