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}

Population on the excited state as a function of waiting time t with (a) and without (b) the IR shield and filters. The square dots are the experimental data and the red lines are the best fit of the exponential decay. The energy relaxation time in panel (a) is T₁ = 1125 ns and in panel (b) is T₁ = 519 ns.