Landau-Zener Transitions in an Adiabatic Quantum Computer
  We report an experimental measurement of Landau-Zener transitions on an individual flux qubit within a multi-qubit superconducting chip designed for adiabatic quantum computation. The method used isolates a single qubit, tunes its tunneling amplitude Delta into the limit where Delta is much less than both the temperature T and the decoherence-induced energy level broadening, and forces it to undergo a Landau-Zener transition. We find that the behavior of the qubit agrees to a high degree of accuracy with theoretical predictions for Landau-Zener transition probabilities for a double-well quantum system coupled to 1/f magnetic flux noise. 
J. Johansson, M.H.S. Amin, A.J. Berkley, P. Bunyk, V. Choi, R. Harris,   M.W. Johnson, T.M. Lanting, Seth Lloyd, G. Rose