Table 2.

Experimentally extracted loss tangents of qubit elements.

Process	${\text{tan}\delta }_{\mathit{pads}}$(${\times 10}^4$)	${\text{tan}\delta }_{\mathit{leads}}$(${\times 10}^4$)	${\text{tan}\delta }_{\mathit{SQUID}}$(${\times 10}^4$)
Lift-off	$11.9\pm 3.1$	$9.4\pm 4.4$	$4.1\pm 1.5$
Wet etch		$7.9\pm 3.7$

Loss tangents extracted using SLE process for the qubit elements by the leads patterning process. The extracted offset relaxation rate ${\mathrm{\Gamma }}_0$ is $204\pm 63{\text{s}}^{-1}$.