Fabrication and Characterization of Aluminum SQUID Transmission Lines

• DOI: 10.1103/physrevapplied.12.064017
• Publication Date: 2019-12-06T10:08:51Z
• Authors: Luca Planat; Ekaterina Al-Tavil; Javier Puertas Ma...; Rémy Dassonneville; Farshad Foroughi; Sébastien Léger; Karthik Bharadwaj; Jovian Delaforce; Vladimir Milchakov; Cécile Naud; Olivier Buisson; Wiebke Hasch-Guic...; Nicolas Roch
• Keywords: Ground plane

We report on the fabrication and characterization of 50 Ohms, flux-tunable, low-loss, SQUID-based transmission lines. The process relies deposition a thin dielectric layer (few tens nanometers) via Atomic Layer Deposition (ALD) top SQUID array, whole structure is then covered by non-superconducting metallic ground plane. present experimental results from five different samples. systematically characterize their microscopic parameters measuring propagating phase in these structures. also investigate losses discriminate conductor losses. This method offers several advantages. First, array does not rely Niobium tri-layer but simpler double angle evaporation technique. Second, ALD provides high quality leading to low-loss devices. Further, based standard, all-aluminum process, allowing direct integration with superconducting qubits. Moreover, our devices are in-situ flux tunable, mitigation incertitude inherent any process. Finally, unit cell being single (no extra capacitance needed), it straightforward modulate size periodically, band-engineering. can be directly applied traveling wave parametric amplifiers.