Contents

22 June 1990
Vol 248, Issue 4962

About The Cover

Pictorial representation of the many-particle state underlying the fractional quantum Hall effect, occurring in two-dimensional electron gases at high magnetic field. The height of the green landscape gives the probability of finding any single electron in relation to its companions (red balls) and to the flux lines (arrows) of the magnetic field. See page 1510. [Illustration courtesy of T. S. Duff and T. Kovacs, AT&T Bell Laboratories]