About the Cover

Placing an atom in one arm of an interferometer destroys the sinusoidal pattern that photons ordinarily produce. But, as artist Geraldine Cox depicts here, overlapping measurements of the atom’s spin and the photon states reveal a hidden pattern. On page 28 , Harrison Ball, Michael Biercuk, and Michael Hush discuss robust manipulation of information in quantum computing, and on page 36 , Marcos Curty, Koji Azuma, and Hoi-Kwong Lo describe how to encode it for quantum cryptography. (Illumination, by Geraldine Cox, oil on canvas, 182 × 146 cm; http://www.findingpatterns.info.)