Daniel A. Lidar,1,* Dave Bacon, Julia Kempe, and K. B. Whaley Department of Chemistry, University of California, Berkeley, California 94720 Department of Physics, University of California, Berkeley, California 94720 Department of Mathematics, University of California, Berkeley, California 94720 École Nationale Superieure des Télécommunications, Paris, France ~Received 19 August 1999; revised ma...
