31 January 1997
Vol 275, Issue 5300

About The Cover

Matter wave interference of two freely expanding and overlapping Bose-Einstein condensates. The density of atomic sodium (vertical axis, in false color) is shown in an area of 0.1 millimeter by 0.4 millimeter containing about 50,000 atoms. The high-contrast interference fringes demonstrate that Bose-Einstein condensates are "laser-like," made of atoms occupying a single controllable quantum state. See 637 and the related News story on 617. [Image: Dallin Durfee]