Extended Data Fig. 8: Transmon dephasing times.
From: Millisecond lifetimes and coherence times in 2D transmon qubits
Tϕ calculated using \({T}_{1}^{{\rm{avg}}}\) and \({T}_{2{\rm{E}}}^{{\rm{avg}}}\) for each qubit. We observe an increase in Tϕ for qubits with UHV-deposited junctions (purple) with a median Tϕ of 2.0 ms compared with qubits with HV-deposited junctions (orange) with a median Tϕ of 0.22 ms. Note that qubit 39 approaches the T2E = 2T1 limit and has a Tϕ of 40 ms. Errors are propagated from the standard error of the T1 and T2E data for each qubit.
