Increasing energy relaxation time of superconducting qubits with nonmagnetic infrared filter and shield

Liu Yuhao¹, Li Mengmeng¹, Lan Dong¹, Xue Guangming¹, Tan Xinsheng^{1, †,}, Yu Haifeng^{1, 2, ‡,}, Yu Yang^{1, 2}

The S parameters of the impedance matched filters measured at different temperatures. Panels (a) and (b) show the attenuation and return loss at room temperature and 77 K, respectively. (c) The impedance calculated from the return loss as a function of frequency.