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, †}

Schematic rf-SQUID phase qubit with Josephson critical current , shunt capacitance C, and loop inductance L. A 3-junction dc-SQUID is used to detect the qubit states.