Researchers succeed in imaging Wigner crystals for the first time

Researchers from University of California at Berkeley, along with additional collaborators, have developed a graphene-based technique for visualizing “Wigner crystals” – a unique sort of crystal that had so far remained impossible to visualize as it tends to “melt” when probed. The crystals are named after physicist Eugene Wigner, who predicted that at low densities and cold temperatures, electrons that usually zip through materials would freeze into place, forming an electron ice, or “Wigner crystal”.

By placing a graphene sheet over the semiconductor sandwich, the team was able to probe the Wigner crystal with a scanning tunneling microscope without melting the sample and demonstrate the crystalline lattice structure, as Wigner predicted.