Evidence Accumulates at Last for the Wigner Crystal

Experimenters may finally have observed the crystalline phase of a degenerate electron gas. Electrons in such a phase do not move freely through the available space; they are confined to the sites of a lattice and their quantum mechanical zero‐point motions are limited to small oscillations about their mean positions. Eugene Wigner had proposed this phase based on his theoretical analyses in the 1930s. The “Wigner crystal” phase has been the focus of much discussion for twenty years, since experimenters have been able to fabricate a variety of systems where the phase might be realized.