Researchers use graphene to achieve direct observation of a magnetic-field-induced Wigner crystal
Researchers from Princeton University, University of California, Lawrence Berkeley National Laboratory and Japan's National Institute for Materials Science have used a special kind of microscope and two pieces of extremely defect-free graphene to capture the clearest and most direct images of a “Wigner crystal”, a structure made entirely of electrons.
Imaging a “Wigner crystal” is extremely hard. At room temperature, electrons can flow together in electric currents because their kinetic energy overcomes the force that makes particles with the same electric charge repel each other. At very low temperatures, however, repulsive electric forces win out, and the electrons end up arranging themselves into a uniform grid, or a crystal. Physicist Eugene Wigner predicted this phenomenon in 1934, but researchers only recently started to understand how to create Wigner crystals in the lab.