  A superconducting chip containing a regular array of flux qubits, tunable
interqubit inductive couplers, an XY-addressable readout system, on-chip
programmable magnetic memory, and a sparse network of analog control lines has
been studied. The architecture of the chip and the infrastructure used to
control it were designed to facilitate the implementation of an adiabatic
quantum optimization algorithm. The performance of an eight-qubit unit cell on
this chip has been characterized by measuring its success in solving a large
set of random Ising spin glass problem instances as a function of temperature.
The experimental data are consistent with the predictions of a quantum
mechanical model of an eight-qubit system coupled to a thermal environment.
These results highlight many of the key practical challenges that we have
overcome and those that lie ahead in the quest to realize a functional large
scale adiabatic quantum information processor.
