High coherence annealing, Part 2: fast annealing experiments*

Recently developed capacitively-shunted flux qubits offer a promising path toward building a high-coherence quantum annealer. These qubits take advantage of lower persistent currents to achieve lower noise sensitivity. Using the fast readout scheme and device discussed in Part 1, Part 2 presents single-qubit annealing experiments performed using RF bias lines. We study the behavior of the qubit transition width by changing the annealing time, and we use excited state readout to determine other parameters of the system. This setup also allows for programming highly nonlinear annealing schedules to probe quantum coherence.