Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2210.12119 · Applied Physics Letters

Tuning the inductance of Josephson junction arrays without SQUIDs

Roman Kuzmin, N. Mehta, Nicholas Grabon, Vladimir Manucharyan

Published Oct 30, 2023• 12 citations
arXivHTMLPDF

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 Fraunhofer-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 characteristic impedance of which is field-tuned in the range of 4–8 kΩ, centered around the important value of the resistance quantum h/(2e)2≈6.5 kΩ.

DOI
10.1063/5.0171047

Related papers

Local tuning of the order parameter in superconducting weak links: A zero-inductance nanodevice

Roni Winik, Itamar Holzman, Emanuele G. Dalla Torre +2 more

Controlling both the amplitude and the phase of the superconducting quantum order parameter ψ in nanostructures is important for next-generation information and communication technologies. The lack of electric resistance in superconductors, which may be advantageous for some technologies, hinders convenient voltage-bias tuning and hence limits the tunability of ψ at the microscopic scale. Here, we demonstrate the local tunability of the phase and amplitude of ψ, obtained by patterning with a single lithography step a Nb nano-superconducting quantum interference device (nano-SQUID) that is biased at its nanobridges. We accompany our experimental results by a semi-classical linearized model that is valid for generic nano-SQUIDs with multiple ports and helps simplify the modelling of non-linear couplings among the Josephson junctions. Our design helped us reveal unusual electric characteristics with effective zero inductance, which is promising for nanoscale magnetic sensing and quantum technologies.

arXiv:1708.05954•Applied Physics Letters•Mar 19, 2018•6 citations

Small-Capacitance Josephson Junctions: One-Dimensional Arrays and Single Junctions

道生 渡部, David B. Haviland

We review experiments on small-capacitance Josephson junctions. When the Josephson junction is fabricated in the configuration of dc superconducting quantum interference device (SQUID), the Josephson coupling can be tuned IN SITU with an external magnetic field. The electrical transport properties of one-dimensional arrays of small-capacitance dc SQUIDs have been investigated in order to study the superconductor-insulator transition. The arrays have also been used to bias a single Josephson junction, and a clear Coulomb blockade of Cooper-pair tunneling has been observed in the single junction.

arXiv:cond-mat/0301340•Jan 20, 2003•2 citations

Static characteristics of superconducting quantum interference devices utilizing the equivalent inductance of Josephson junctions

Yoshinao Mizugaki, Koji Nakajima

It is necessary to miniaturize inductors for large-scale integration of Josephson devices. Utilizing the equivalent inductance of Josephson junctions is one promising method to realize small inductors. In this paper we calculate the static characteristics of some superconducting quantum interference devices (SQUIDs) utilizing the equivalent inductance, and we compare the results with those of SQUIDs employing the normal inductors. We also discuss the current distribution before and after the transition of the gate junctions. © 1998 Scripta Technica, Electron Comm Jpn Pt 2, 81(6): 1–7, 1998

Electronics and Communications in Japan (Part II Electronics)•Jun 1, 1998•0 citations

Design and experimental study of superconducting left-handed transmission lines with tunable dispersion

Е. А. Овчинникова, S. Butz, P. Jung +5 more

We study the microwave properties of a superconducting tunable coplanar waveguide (CPW). Pairs of Josephson junctions are forming superconducting quantum interference devices (SQUIDs), which shunt the central conductor of the CPW. The Josephson inductance of the SQUIDs is varied in the range of 0.08–0.5 nH by applying a dc magnetic field. The central conductor of the CPW contains Josephson junctions connected in series that provide extra inductances; the magnetic field controlling the SQUIDs is weak enough not to influence the inductance of the chain of the single junctions. The circuit is designed to have left- and right-handed transmission properties separated by a variable rejection band; the band edges can be tuned by the magnetic field. We present transmission measurements on CPWs based on up to 120 Nb–AlO x –Nb Josephson junctions. At zero magnetic field, we observed no rejection band in the frequency range of 8–11 GHz. When applying the magnetic field, a rejection band between 7 GHz and 9 GHz appears. The experimental data are compared with numerical simulations.

arXiv:1309.7557•Superconductor Science and Technology•Oct 7, 2013•16 citations

Tunable microwave impedance matching to a high impedance source using a Josephson metamaterial

Carles Altimiras, Olivier Parlavecchio, P. Joyez +4 more

We report the efficient coupling of a 50 Ω microwave circuit to a high impedance conductor. We use an impedance transformer consisting of a λ/4 co-planar resonator whose inner conductor contains an array of superconducting quantum interference devices (SQUIDs), providing it with a tunable lineic inductance L∼80 μ0, resulting in a characteristic impedance ZC∼1 kΩ. The impedance matching efficiency is characterized by measuring the shot noise power emitted by a dc biased tunnel junction connected to the resonator. We demonstrate matching to impedances in the 15 to 35 kΩ range with bandwidths above 100 MHz around a resonant frequency tunable between 4 and 6 GHz.

arXiv:1404.1792•Applied Physics Letters•Nov 18, 2013•53 citations

Local tunability in a multi-port SQUID by an injection current

Zuyu Xu, Wanghao Tian, Shixian Chen +12 more

Abstract The tunability in Josephson junctions is foundational to the superconducting classical and quantum applications. Here, we demonstrate the local manipulation of supercurrent realized in a superconducting quantum interference device (SQUID) with two Nb/TiO x /Nb Josephson junctions that is biased at the TiO x layer. Our measurements indicate that the multi-port device allows for an easy and in situ tunability of the supercurrent. The control mechanism can be finely explained by simple yet valid theoretical methods, which take an effective electronic temperature across the SQUID and the self inductive magnetic flux into account. Furthermore, we show that the phase difference and kinetic inductance of this device can be tuned locally via the injection current. Thus, the device provides perspective for several superconducting electronics such as tunable superconducting circuits, sensitive magnetometry, and fast digital elements.

Superconductor Science and Technology•Oct 19, 2021•3 citations
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 Fraunhofer-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 characteristic impedance of which is field-tuned in the range of 4–8 kΩ, centered around the important value of the resistance quantum h/(2e)2≈6.5 kΩ.
Controlling both the amplitude and the phase of the superconducting quantum order parameter ψ in nanostructures is important for next-generation information and communication technologies. The lack of electric resistance in superconductors, which may be advantageous for some technologies, hinders convenient voltage-bias tuning and hence limits the tunability of ψ at the microscopic scale. Here, we demonstrate the local tunability of the phase and amplitude of ψ, obtained by patterning with a single lithography step a Nb nano-superconducting quantum interference device (nano-SQUID) that is biased at its nanobridges. We accompany our experimental results by a semi-classical linearized model that is valid for generic nano-SQUIDs with multiple ports and helps simplify the modelling of non-linear couplings among the Josephson junctions. Our design helped us reveal unusual electric characteristics with effective zero inductance, which is promising for nanoscale magnetic sensing and quantum technologies.
We review experiments on small-capacitance Josephson junctions. When the Josephson junction is fabricated in the configuration of dc superconducting quantum interference device (SQUID), the Josephson coupling can be tuned IN SITU with an external magnetic field. The electrical transport properties of one-dimensional arrays of small-capacitance dc SQUIDs have been investigated in order to study the superconductor-insulator transition. The arrays have also been used to bias a single Josephson junction, and a clear Coulomb blockade of Cooper-pair tunneling has been observed in the single junction.
It is necessary to miniaturize inductors for large-scale integration of Josephson devices. Utilizing the equivalent inductance of Josephson junctions is one promising method to realize small inductors. In this paper we calculate the static characteristics of some superconducting quantum interference devices (SQUIDs) utilizing the equivalent inductance, and we compare the results with those of SQUIDs employing the normal inductors. We also discuss the current distribution before and after the transition of the gate junctions. © 1998 Scripta Technica, Electron Comm Jpn Pt 2, 81(6): 1–7, 1998
We study the microwave properties of a superconducting tunable coplanar waveguide (CPW). Pairs of Josephson junctions are forming superconducting quantum interference devices (SQUIDs), which shunt the central conductor of the CPW. The Josephson inductance of the SQUIDs is varied in the range of 0.08–0.5 nH by applying a dc magnetic field. The central conductor of the CPW contains Josephson junctions connected in series that provide extra inductances; the magnetic field controlling the SQUIDs is weak enough not to influence the inductance of the chain of the single junctions. The circuit is designed to have left- and right-handed transmission properties separated by a variable rejection band; the band edges can be tuned by the magnetic field. We present transmission measurements on CPWs based on up to 120 Nb–AlO x –Nb Josephson junctions. At zero magnetic field, we observed no rejection band in the frequency range of 8–11 GHz. When applying the magnetic field, a rejection band between 7 GHz and 9 GHz appears. The experimental data are compared with numerical simulations.
We report the efficient coupling of a 50 Ω microwave circuit to a high impedance conductor. We use an impedance transformer consisting of a λ/4 co-planar resonator whose inner conductor contains an array of superconducting quantum interference devices (SQUIDs), providing it with a tunable lineic inductance L∼80 μ0, resulting in a characteristic impedance ZC∼1 kΩ. The impedance matching efficiency is characterized by measuring the shot noise power emitted by a dc biased tunnel junction connected to the resonator. We demonstrate matching to impedances in the 15 to 35 kΩ range with bandwidths above 100 MHz around a resonant frequency tunable between 4 and 6 GHz.
Abstract The tunability in Josephson junctions is foundational to the superconducting classical and quantum applications. Here, we demonstrate the local manipulation of supercurrent realized in a superconducting quantum interference device (SQUID) with two Nb/TiO x /Nb Josephson junctions that is biased at the TiO x layer. Our measurements indicate that the multi-port device allows for an easy and in situ tunability of the supercurrent. The control mechanism can be finely explained by simple yet valid theoretical methods, which take an effective electronic temperature across the SQUID and the self inductive magnetic flux into account. Furthermore, we show that the phase difference and kinetic inductance of this device can be tuned locally via the injection current. Thus, the device provides perspective for several superconducting electronics such as tunable superconducting circuits, sensitive magnetometry, and fast digital elements.