Fig. 4: Effect of qubit geometry.
From: Systematic improvements in transmon qubit coherence enabled by niobium surface encapsulation
a T1 comparison of Nb/Ta qubits as a function of three different qubit geometries prepared on sapphire substrates. Geometry B yields the largest T1 values. Error bars represent 95% confidence interval. b Statistics for T1 consecutively measured over 70 h for a Geometry B qubit. The average T1 (μT1) is 323 μs. c Decay curve associated with measured T1 value of 586 μs (indicated by star in (b)).
