J. Hertzberg

Ultrahigh Vacuum Packaging and Surface Cleaning for Quantum Devices

  1. M. Mergenthaler,
  2. S. Paredes,
  3. P. Müller,
  4. C. Müller,
  5. S. Filipp,
  6. M. Sandberg,
  7. J. Hertzberg,
  8. V. P. Adiga,
  9. M. Brink,
  10. and A. Fuhrer
We describe design, implementation and performance of an ultra-high vacuum (UHV) package for superconducting qubit chips or other surface sensitive quantum devices. The UHV loading
procedure allows for annealing, ultra-violet light irradiation, ion milling and surface passivation of quantum devices before sealing them into a measurement package. The package retains vacuum during the transfer to cryogenic temperatures by active pumping with a titanium getter layer. We characterize the treatment capabilities of the system and present measurements of flux tunable qubits with an average T1=84 μs and Techo2=134 μs after vacuum-loading these samples into a bottom loading dilution refrigerator in the UHV-package.
arxiv pdf