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=84μs and T2echo=134μs after vacuum-loading these samples into a bottom loading dilution refrigerator in the UHV-package.
Cite
@article{arxiv.2010.12090,
title = {Ultrahigh Vacuum Packaging and Surface Cleaning for Quantum Devices},
author = {M. Mergenthaler and S. Paredes and P. Müller and C. Müller and S. Filipp and M. Sandberg and J. Hertzberg and V. P. Adiga and M. Brink and A. Fuhrer},
journal= {arXiv preprint arXiv:2010.12090},
year = {2022}
}