Tuning the inductance of Josephson junction arrays without SQUIDs

Roman Kuzmin; Nitish Mehta; Nicholas Grabon; Vladimir E. Manucharyan

doi:10.1063/5.0171047

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arXiv · 2210.12119

Tuning the inductance of Josephson junction arrays without SQUIDs

Roman Kuzmin·Nitish Mehta·Nicholas Grabon·Vladimir E. Manucharyan

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Abstract

It is customary to use arrays of superconducting quantum interference devices (SQUIDs) for implementing magnetic field-tunable inductors. Here, we demonstrate an equivalent tunability in a (SQUID-free) array of single Al/AlOx/Al Josephson tunnel junctions. With the proper choice of junction geometry, a perpendicularly applied magnetic field bends along the plane of the superconductor and focuses into the tunnel barrier region due to a demagnetization effect. Consequently, the Josephson inductance can be efficiently modulated by the Fraunhoffer-type supercurrent interference. The elimination of SQUIDs not only simplifies the device design and fabrication, but also facilitates a denser packing of junctions and, hence, a higher inductance per unit length. As an example, we demonstrate a transmission line, the wave impedance of which is field-tuned in the range of $4-8~\textrm{k}\Omega$, centered around the important value of the resistance quantum $h/(2e)^2 \approx 6.5~\textrm{k}\Omega$.

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cond-mat.supr-con cond-mat.mes-hall physics.app-ph quant-ph

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Roman Kuzmin, Nitish Mehta, Nicholas Grabon, Vladimir E. Manucharyan. 2022-10-21. Tuning the inductance of Josephson junction arrays without SQUIDs. https://doi.org/10.1063/5.0171047

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