08 October 1993
Vol 262, Issue 5131

About The Cover

Scanning tunneling microscope (STM) image of a quantum corral. The 48 iron atoms (blue peaks) forming the corral (diameter, 143 angstroms) were arranged on a copper surface with the tip of the STM. The circular oscillations reveal the density distribution of electrons occupying quantum states of the corral. Corrals shape the spatial distribution of surface state electrons so that the properties of electrons in reduced-dimension systems can be studied. See page 218, the News story on page 178, and the Perspective on page 195. [Image: IBM Research Division]