Number 13 (Story #4), December 17, 1990 by Phillip F. Schewe and Ben Stein A WIGNER CRYSTAL , a two-dimensional array of electrons confined to the sites of a lattice, may have been observed by two scientific teams: a Stony Brook-Princeton-AT&T Bell Labs group and a Saclay-Rutgers-Bagneux-Philips collaboration. Unlike the crystalline phase of electron an electron gas observed (in 1979) above a sample of liquid helium, the present electron crystal phase, first hypothesized by Eugene Wigner in the 1930s, is believed to be governed by quantum effects. Evidence for the Wigner crystal comes from experiments on the two-dimensional electron gas which forms (in the presence of a strong magnetic field) at the interface between GaAs and AlGaAs layers in a heterojunction. (Physics Today, December 1990.)