2021/11/01 by J. Krause, Jonas Krause, C. Dickel +10 · 30 citations
Computer Science · Physics and Astronomy · #Condensed matter physics #Electrical engineering #Josephson effect #Magnetic field #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum mechanics #Qubit #Squid #Superconductivity #Topology (electrical circuits) #Transmon #cond-mat.supr-con #quant-ph
paper · pdf · doi:10.1103/physrevapplied.17.034032
published in Physical Review Applied 17(3) (American Physical Society)
arxiv created 2021/11/01 · openalex publication_date 2022/03/11 · arxiv updated 2022/03/15 · openalex created_date 2022/04/03 · openalex updated_date 2026/08/06
Magnetic-field-resilient superconducting circuits enable sensing applications and hybrid quantum-computing architectures involving spin or topological qubits and electro-mechanical elements, as well as studying flux noise and quasiparticle loss. We investigate the effect of in-plane magnetic fields up to 1 T on the spectrum and coherence times of thin-film 3D aluminum transmons. Using a copper cavity, unaffected by strong magnetic fields, we can solely probe the magnetic-field effect on the transmons. We present data on a single-junction and a SQUID transmon, that were cooled down in the same cavity. As expected, transmon frequencies decrease with increasing fields, due to a suppression of the superconducting gap and a geometric Fraunhofer-like contribution. Nevertheless, the thin-film transmons show strong magnetic-field resilience: both transmons display microsecond coherence up to at least 0.65 T, and T1 remains above 1 \mathrmμs over the entire measurable range. SQUID spectroscopy is feasible up to 1 T, the limit of our magnet. We conclude that thin-film aluminum Josephson junctions are a suitable hardware for superconducting circuits in the high-magnetic-field regime.