Speaker
Description
The last decades have seen significant advances in coherence times of superconducting qubits. This was mainly made possible by reducing charge dispersion of transmon qubits, better thermalization and filtering of the readout and control circuitry as well as improvements in Josephson junction fabrication. Lately, efforts are being made in order to investigate limitations of coherence due to material interfaces and two level fluctuators [1-3].
Here we present our work towards understanding decoherence mechanisms in transmon qubits via surface treatments and sample packaging. We show qubit packaging under UHV or a controlled atmosphere, study surface treatments and discuss coherence data from measured devices.
[1]J.M.Gambetta, et al., IEEE Trans.Appl.Supercond., 27, (2016).
[2]S.DeGraaf et al., Nat.Communications 9, (2017)
[3]C.Müller et al., arXiv:1705.01108 (2017)
