The tunneling of quasiparticles (QPs) across Josephson junctions (JJs) detrimentally affects the coherence of superconducting and charge-parity qubits, and is shown to occur more frequently in magnetic fields. Here we demonstrate the parity lifetime to survive in excess of 50μs in magnetic fields up to 1T, utilising a semiconducting nanowire transmon to detect QP tunneling in real time. We exploit gate-tunable QP filters and find magnetic-field-enhanced parity lifetimes, consistent with increased QP trapping by the ungated nanowire due to orbital effects. Our findings highlight the importance of QP trap engineering for building magnetic-field compatible hybrid superconducting circuits.
@article{arxiv.2105.11038,
title = {Quasiparticle trapping by orbital effect in a hybrid superconducting-semiconducting circuit},
author = {Willemijn Uilhoorn and James G. Kroll and Arno Bargerbos and Syed D. Nabi and Chung-Kai Yang and Peter Krogstrup and Leo P. Kouwenhoven and Angela Kou and Gijs de Lange},
journal= {arXiv preprint arXiv:2105.11038},
year = {2021}
}