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

Superconductor Science and Technology

Two-dimensional arrays of Josephson junctions as voltage-tunable oscillators

Samuel P. Benz, Charles J. Burroughs

Published Nov 1, 1991• 52 citations
Publisher

Abstract

The authors have detected coherent emission from two-dimensional (2D) arrays of superconductor-insulator-superconductor (SIS) Josephson junctions. 2D arrays emit coherent radiation over a frequency range of 60 to 210 GHz, when coupled to detector junctions through DC-blocking capacitors. The detector junctions exhibit Shapiro steps at frequencies corresponding to the voltage across single-array junctions. The maximum power from a 10-by-10 junction-array coupled to a detector junction occurs at 150 GHz and is estimated to be 0.4 mu W, based on simulations of the detector circuit. By varying the number of array junctions, the array geometry, the junction critical current, and the coupling circuit, they have begun determining the essential conditions for observing coherent emission.

DOI
10.1088/0953-2048/4/11/002

Related papers

Coherent emission from two-dimensional Josephson junction arrays

S. P. Benz, Charles J. Burroughs

Coherent emission has been generated by two-dimensional arrays of SIS Josephson junctions and detected in a junction coupled to the array through a dc-blocking capacitor. The detector junction exhibits Shapiro steps at frequencies corresponding to the voltage across single array junctions and ranging from 60 to 210 GHz. The maximum power coupled to the detector junction occurs at 150 GHz and is estimated to be 0.9 μW, based on simulations of the detector circuit. Possible mechanisms for coherent emission from two-dimensional arrays are discussed.

Applied Physics Letters•May 13, 1991•182 citations

Frequency dependence of the emission from 2D array Josephson oscillators

P.A.A. Booi, Samuel P. Benz, T. Doderer +4 more

Coherent emission from 2-D arrays of Josephson junctions, coupled to a detector junction through a DC blocking stripline capacitor, was detected over a frequency range from 50 to 210 GHz. A power of 0.26 mu W, which is larger than the 0.1 mu W expected from the resistively shunted-junction model, was detected in a range from 140 to 150 GHz. Frequencies where no emission was detected correspond to standing waves in the capacitor when multiples of the half-wavelength match the capacitor length. Low-temperature scanning electron microscopy confirmed the presence of standing waves at these frequencies, but also revealed standing waves at other frequencies, indicating an impedance mismatch and a possible extension of the standing waves into the array.>

IEEE Transactions on Applied Superconductivity•Mar 1, 1993•16 citations

Resonances in two-dimensional array oscillator circuits

P.A.A. Booi, Samuel P. Benz

We present experimental results on the emission from phase-locked two-dimensional arrays of Josephson junctions. We have coupled the emission from 10/spl times/10 arrays to a room-temperature mixer through a fin-line antenna and WR-12 waveguide. A single voltage-tunable peak was detected up to 230 GHz. A stripline resonance in antenna reduced the array's dynamic resistance and thereby the emission linewidth to as low as 10 kHz. We extract an effective noise temperature of 14 K from the linewidth data. When the array's emission was coupled to an on-chip detector junction through a dc blocking capacitor, we detected voltage-tunable emission from 75 GHz up to 300 GHz, and in some circuits emission above 400 GHz. Here, the coherent power spectrum depends on internal resonances.>

IEEE Transactions on Applied Superconductivity•Jun 1, 1995•12 citations

Characterization of the Emission from 2D Array Josephson Oscillators

P.A.A. Booi, Samuel P. Benz

We present experimental results on the emission from phase-locked twodimensional arrays of Josephson junctions. We have coupled the emission from 10 x 10 arrays to a room-temperature mixer throu h a tin-line antenna and WR-12 waveguide. A single voltagetunable peak was detected up to 230 GHz. A stripline resonance in the antenna reduced the array's dynamic resistance and thereby the emission linewidth to as low as 10 kHz. We extract an effective noise temperature of 14 K from the linewidth data. When the array's emission was coupled to an on-chip detector junction through a dc blocking capacitor, we detected voltagetunable emission from 75 GHz up to 300 GHz, and in some circuits emission above 400 GHz. The coherent power spectrum depends primarily on internal resonances.

•May 1, 1994•1 citation

Detailed investigation of two-dimensional Josephson junction array circuits

M. Keek, T. Doderer, R. Mueller +7 more

We have investigated two-dimensional arrays of overdamped Josephson junctions that have been fabricated in Nb/Al/sub 2/O/sub 3//Nb-technology, together with microwave coupling structures. Different arrays have shown to emit coherent microwave radiation by using microwave-coupled on-chip detectors. Low-temperature scanning electron microscopy is used to study the coupling of the microwave radiation to an on-chip load. From the appearance of Shapiro steps in the current vs. voltage curves of detector junctions for different degrees of disorder in the array-junctions, margins of the spread in the critical currents of the Josephson junctions for coherent oscillation can be drawn.

IEEE Transactions on Applied Superconductivity•Jun 1, 1997•6 citations

Fundamental and harmonic submillimeter-wave emission from parallel Josephson junction arrays

Faouzi M. Boussaha, Morvan C. Salez, A. Féret +6 more

We report heterodyne measurements of Josephson microwave radiation emitted by a parallel array of small superconductor-insulator-superconductor (SIS) junctions at submillimeter-wave frequencies. The array consists of five Nb/Al–AlOx/Nb junctions nonevenly distributed in a niobium superconducting stripline, and is optimized for rf coupling in the 450–640 GHz range. We observed Fiske-like resonant steps in its I-V curve in the presence of magnetic field. The device was placed in a waveguide mount, and its radiation was quasioptically coupled out of the cryostat, to a SIS-mixer spectrometer in the same frequency range, with a 4–8 GHz band for spectral analysis. We detected a coherent signal in the spectra when the array was biased on the first and third steps, respectively, at the first harmonic frequency of 242 GHz and at the fundamental frequency of 493 GHz, both being the Josephson frequencies associated with their dc voltages. This strongly suggests that this type of parallel arrays optimized for wideband rf coupling, though strongly discretized, hosts dynamic fluxon regimes similar to long Josephson junctions, which could find applications in superconducting digital electronics or integrated heterodyne submillimeter-wave receivers.

Journal of Applied Physics•Apr 1, 2009•7 citations
The authors have detected coherent emission from two-dimensional (2D) arrays of superconductor-insulator-superconductor (SIS) Josephson junctions. 2D arrays emit coherent radiation over a frequency range of 60 to 210 GHz, when coupled to detector junctions through DC-blocking capacitors. The detector junctions exhibit Shapiro steps at frequencies corresponding to the voltage across single-array junctions. The maximum power from a 10-by-10 junction-array coupled to a detector junction occurs at 150 GHz and is estimated to be 0.4 mu W, based on simulations of the detector circuit. By varying the number of array junctions, the array geometry, the junction critical current, and the coupling circuit, they have begun determining the essential conditions for observing coherent emission.
Coherent emission has been generated by two-dimensional arrays of SIS Josephson junctions and detected in a junction coupled to the array through a dc-blocking capacitor. The detector junction exhibits Shapiro steps at frequencies corresponding to the voltage across single array junctions and ranging from 60 to 210 GHz. The maximum power coupled to the detector junction occurs at 150 GHz and is estimated to be 0.9 μW, based on simulations of the detector circuit. Possible mechanisms for coherent emission from two-dimensional arrays are discussed.
Coherent emission from 2-D arrays of Josephson junctions, coupled to a detector junction through a DC blocking stripline capacitor, was detected over a frequency range from 50 to 210 GHz. A power of 0.26 mu W, which is larger than the 0.1 mu W expected from the resistively shunted-junction model, was detected in a range from 140 to 150 GHz. Frequencies where no emission was detected correspond to standing waves in the capacitor when multiples of the half-wavelength match the capacitor length. Low-temperature scanning electron microscopy confirmed the presence of standing waves at these frequencies, but also revealed standing waves at other frequencies, indicating an impedance mismatch and a possible extension of the standing waves into the array.>
We present experimental results on the emission from phase-locked two-dimensional arrays of Josephson junctions. We have coupled the emission from 10/spl times/10 arrays to a room-temperature mixer through a fin-line antenna and WR-12 waveguide. A single voltage-tunable peak was detected up to 230 GHz. A stripline resonance in antenna reduced the array's dynamic resistance and thereby the emission linewidth to as low as 10 kHz. We extract an effective noise temperature of 14 K from the linewidth data. When the array's emission was coupled to an on-chip detector junction through a dc blocking capacitor, we detected voltage-tunable emission from 75 GHz up to 300 GHz, and in some circuits emission above 400 GHz. Here, the coherent power spectrum depends on internal resonances.>
We present experimental results on the emission from phase-locked twodimensional arrays of Josephson junctions. We have coupled the emission from 10 x 10 arrays to a room-temperature mixer throu h a tin-line antenna and WR-12 waveguide. A single voltagetunable peak was detected up to 230 GHz. A stripline resonance in the antenna reduced the array's dynamic resistance and thereby the emission linewidth to as low as 10 kHz. We extract an effective noise temperature of 14 K from the linewidth data. When the array's emission was coupled to an on-chip detector junction through a dc blocking capacitor, we detected voltagetunable emission from 75 GHz up to 300 GHz, and in some circuits emission above 400 GHz. The coherent power spectrum depends primarily on internal resonances.
We have investigated two-dimensional arrays of overdamped Josephson junctions that have been fabricated in Nb/Al/sub 2/O/sub 3//Nb-technology, together with microwave coupling structures. Different arrays have shown to emit coherent microwave radiation by using microwave-coupled on-chip detectors. Low-temperature scanning electron microscopy is used to study the coupling of the microwave radiation to an on-chip load. From the appearance of Shapiro steps in the current vs. voltage curves of detector junctions for different degrees of disorder in the array-junctions, margins of the spread in the critical currents of the Josephson junctions for coherent oscillation can be drawn.
We report heterodyne measurements of Josephson microwave radiation emitted by a parallel array of small superconductor-insulator-superconductor (SIS) junctions at submillimeter-wave frequencies. The array consists of five Nb/Al–AlOx/Nb junctions nonevenly distributed in a niobium superconducting stripline, and is optimized for rf coupling in the 450–640 GHz range. We observed Fiske-like resonant steps in its I-V curve in the presence of magnetic field. The device was placed in a waveguide mount, and its radiation was quasioptically coupled out of the cryostat, to a SIS-mixer spectrometer in the same frequency range, with a 4–8 GHz band for spectral analysis. We detected a coherent signal in the spectra when the array was biased on the first and third steps, respectively, at the first harmonic frequency of 242 GHz and at the fundamental frequency of 493 GHz, both being the Josephson frequencies associated with their dc voltages. This strongly suggests that this type of parallel arrays optimized for wideband rf coupling, though strongly discretized, hosts dynamic fluxon regimes similar to long Josephson junctions, which could find applications in superconducting digital electronics or integrated heterodyne submillimeter-wave receivers.