A Cross-Type SNS Junction Array for a Quantum-Based Arbitrary Waveform Synthesizer

Schubert, M.; May, T.; Wende, G.; Meyer, H.‐G.

doi:10.1109/tasc.2005.850072

Cited by 18 publications

(10 citation statements)

References 8 publications

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“…However, this value of suppression parameter is difficult to implement. It is, for this reason, the experimentally obtained magnitudes of characteristic voltage is rather small [18,[44][45][46][47][48][49][50][51][52][53]. Note that a simple decrease in the N -layer thickness is not a solution of this problem.…”

Section: Scalability Of Josephson Junctionsmentioning

confidence: 95%

Miniaturization of Josephson Junctions for Digital Superconducting Circuits

et al. 2021

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In this work, we briefly overview various options for Josephson junctions, which should be scalable down to nanometer range for utilization in nanoscale digital superconducting technology. Such junctions should possess high values of critical current, I c , and normal state resistance, R N . Another requirement is the high reproducibility of the junction parameters across a wafer in a fabrication process. We argue that superconductor-normal metal-superconductor (SN -N -NS) Josephson junction of "variable thickness bridge" geometry is a promising choice to meet these requirements. Theoretical analysis of the SN -N -NS junction is performed in the case where the distance between the S electrodes is comparable to the coherence length of the N material. The restriction on the junction geometrical parameters providing the existence of superconductivity in the S electrodes is derived for the current flowing through the junction of an order of I c . The junction heating, as well as available mechanisms for the heat removal, is analyzed. The obtained results show that a SN -N -NS junction with a high (submillivolt) value of I c R N product can be fabricated from a broadly utilized combination of materials like Nb/Cu using well-established technological processes. The junction area can be scaled down to that of semiconductor transistors fabricated in the frame of a 40-nm process.

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Section: Scalability Of Josephson Junctionsmentioning

confidence: 95%

Miniaturization of Josephson Junctions for Digital Superconducting Circuits

et al. 2021

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“…The second advance [12] was to "ac-couple" the digital bias, which removed unwanted common-mode signals on the termination resistors and thereby enabled series connection of two arrays, doubling the combined output voltage. Other advances such as cryopackaging [28], stacked junctions [29], [30], new materials for Josephson junction barriers [31]- [33], bias lead filters [34], and tapered transmission lines [35] also contributed to increasing the RMS voltage per array to 138 mV. Fig.…”

Section: Waveform Synthesis With Quantized Pulsesmentioning

confidence: 99%

Pulse-Bias Electronics and Techniques for a Josephson Arbitrary Waveform Synthesizer

Benz

Waltman

2014

IEEE Trans. Appl. Supercond.

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The Josephson arbitrary waveform synthesizer (JAWS) is a series array of thousands of superconducting Josephson junctions that are biased by current pulses such that the array produces voltage waveforms with quantum accuracy. Intrinsically accurate voltage waveforms synthesized with the quantized pulses from Josephson junctions were first demonstrated in 1996. Ten years later, a commercial ac standard was calibrated at an output root-mean-square (RMS) amplitude of 100 mV with the first practical superconducting digital-to-analog converter. Since then, many different bias techniques, pulse-drive electronics, and device technology have been developed and improved in order to achieve a maximum of 138 mV output RMS voltage per Josephson array. In this paper, we report new bias electronics and demonstrate two new pulse-bias techniques. The first technique has demonstrated 250 mV output RMS voltage per 6400-junction array and may enable a practical 1 V system with only four arrays. The second bias technique reduces inductance-related error signals at the signal frequency and should reduce systematic errors for waveforms with frequencies greater than 1 MHz.

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“…However, this value of suppression parameter is difficult to implement. It is, for this reason, the experimentally obtained magnitudes of characteristic voltage is rather small [18,[45][46][47][48][49][50][51][52][53][54]. Note that a simple decrease in the N layer thickness is not a solution of this problem.…”

Section: Introductionmentioning

confidence: 95%

Miniaturization of Josephson junction for digital superconducting circuits

Soloviev¹,

Bakurskiy²,

Ruzhickiy³

et al. 2021

Preprint

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In this work we briefly overview various options for Josephson junctions which should be scalable down to nanometer range for utilization in nanoscale digital superconducting technology. Such junctions should possess high values of critical current, Ic, and normal state resistance, Rn. Another requirement is the high reproducibility of the junction parameters across a wafer in a fabrication process. We argue that Superconductor -Normal metal -Superconductor (SN-N-NS) Josephson junction of "variable thickness bridge" geometry is a promising choice to meet these requirements. Theoretical analysis of SN-N-NS junction is performed in the case where the distance between the S-electrodes is comparable to the coherence length of the N-material. The restriction on the junction geometrical parameters providing the existence of superconductivity in the S-electrodes is derived for the current flowing through the junction of an order of Ic. The junction heating as well as available mechanisms for the heat removal is analyzed. The obtained results show that an SN-N-NS junction with a high (sub-millivolt) value of IcRn product can be fabricated from a broadly utilized combination of materials like Nb/Cu using well-established technological processes. The junction area can be scaled down to that of semiconductor transistors fabricated in the frame of a 40-nm process.

show abstract

A Cross-Type SNS Junction Array for a Quantum-Based Arbitrary Waveform Synthesizer

Cited by 18 publications

References 8 publications

Miniaturization of Josephson Junctions for Digital Superconducting Circuits

Miniaturization of Josephson Junctions for Digital Superconducting Circuits

Pulse-Bias Electronics and Techniques for a Josephson Arbitrary Waveform Synthesizer

Miniaturization of Josephson junction for digital superconducting circuits

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