Contents

03 June 2011
Vol 332, Issue 6034

About The Cover

Cover image expansion

COVER Three possible phases of the kagome Heisenberg antiferromagnet, a model of geometrically "frustrated " magnetism: the diamond-pattern valence bond crystal (lower left), honeycomb valence bond crystal (lower right), and quantum spin liquid (upper empty wedge). Deviations of bond strengths from their average values are shown by bond widths and colors (red, stronger; blue, weaker). The simulations of Yan et al. (p. 1173) show that the true ground-state phase is the quantum spin liquid. Image: Steven R. White, University of California, Irvine