Superconducting phase qubits with shadow-evaporated Josephson junctions

Su Fei-Fan^{1, 2}, Liu Wei-Yang^{1, 2}, Xu Hui-Kai^{1, 2}, Deng Hui¹, Li Zhi-Yuan^{1, 3}, Tian Ye¹, Zhu Xiao-Bo⁴, Zheng Dong-Ning¹, Lv Li¹, Zhao Shi-Ping^{1, 2, 5, †}

(color online) (a) Swap spectroscopy of the phase qubit showing no oscillation patterns from coherently coupled barrier TLS. (b) The timing of the flux bias pulses (blue) and microwave π-pulse (green) for the measurement.