Experimental Findings on the Superconducting Quantum Annealing Circuit and those Applications to a Gate-Type Quantum Computer

The superconducting quantum annealing circuit is constructed with four Nb layers and Josephson junctions with a critical current density of 1 μA/μm2. Three key points exist to perform the quantum annealing in experiments. First, the shape of the energy potential of the qubit should be accurately designed. Second, the current pulses for modulation of the shape of the energy potential must propagate to the qubit accurately. Third is the suppression of noise in the environment where the qubit is placed. Furthermore, calibration of the measurement data is necessary with consideration of the experimental environment. In this paper, I will present a mechanism for realizing quantum annealing from two perspectives: a theoretical model and an experiment. Experimental findings on quantum annealing will contribute to study of the surrounding circuit of a gate-type quantum computer.