S. Zorzetti

Three-dimensional superconducting resonators at T<20 mK with the photon lifetime up to τ=2 seconds

  1. A. Romanenko,
  2. R. Pilipenko,
  3. S. Zorzetti,
  4. D. Frolov,
  5. M. Awida,
  6. S. Posen,
  7. and A. Grassellino
Very high quality factor superconducting radio frequency cavities developed for accelerators can offer a path to a 1000-fold increase in the achievable coherence times for cavity-stored
quantum states in the 3D circuit QED architecture. Here we report the first measurements of several accelerator cavities of f_0=1.3, 2.6, 5 GHz resonant frequencies down to temperatures of about 10~mK and field levels down to a few photons, which reveal record high photon lifetimes up to 2 seconds, while also further exposing the role of the two level systems (TLS) in the niobium oxide. We also demonstrate how the TLS contribution can be greatly suppressed by the special vacuum heat treatment.
arxiv pdf