Datasets for the four published figures in the Paper "AC Metrology Applications of the Josephson Effect ". This paper is being submitted to Applied Physics Letters Special Topic, "Advances in Quantum Metrology,"https://publishing.aip.org/publications/journals/special-topics/apl/advances-in-quantum-metrology/ .Abstract of the paper:The performance of programmable voltage signals that exploit the quantum behavior of superconducting Josephson junctions continues to improve and enable new capabilities for applications in metrology, communications, and quantum control. We review advances in pulse-driven digital synthesis techniques with Josephson-junction-based devices. Unprecedented performance for synthesized voltage waveforms has been achieved at different frequencies, including rms amplitudes of 4 V at 1 kHz, 50 mV at 50 MHz, and 22 mV at 1.005 GHz. Josephson pulse generators have also successfully controlled and characterized superconducting qubits with a gate fidelity of 99.5%.

These data will appear in [1]. The abstract for that paper is given below:We report on the design, fabrication, and measurement of a Very High Frequency band Josephson Arbitrary Waveform Synthesizer (VHF-JAWS) at frequencies from 1~kHz to 50.05~MHz. The VHF-JAWS chip is composed of a series array of 12,810 Josephson junctions (JJs) embedded in a superconducting coplanar waveguide. Each JJ responds to a pattern of current pulses by creating a corresponding pattern of voltage pulses, each with a time-integrated area related to fundamental constants as $ extit{ extbf{h/2e}}$. The pulse patterns are chosen to produce quantum-based single-tone voltage waveforms with an open-circuit voltage of 50~mV~rms (\mbox{-19.03~dBm} output power into 50~$\Omega$ load impedances) at frequencies up to 50.05~MHz, which is more than twice the voltage that has been generated by previous RF-JAWS designs at 1~GHz. The VHF-JAWS is "quantum-locked", that is, it generates one quantized output voltage pulse per input current pulse per JJ while varying the dc current through the JJ array by at least 0.4~mA and the amplitude of the bias pulses by at least 10~\%. We use the large bias pulse quantum-locking range to investigate one source of error in detail: the direct feedthrough of the current bias pulses into the DUT at VHF frequencies. We reduce this error by high-pass filtering the current bias pulses and measure the error as a function of input pulse amplitude using two techniques: by measuring small changes over the quantum-locking range and by passively attenuating the input pulse amplitude so that the nonlinear JJs no longer generate voltage pulses while the error is only linearly scaled.

These data will appear in [1]. The abstract for that paper is given below:We report on the design, fabrication, and measurement of a Very High Frequency band Josephson Arbitrary Waveform Synthesizer (VHF-JAWS) at frequencies from 1~kHz to 50.05~MHz. The VHF-JAWS chip is composed of a series array of 12,810 Josephson junctions (JJs) embedded in a superconducting coplanar waveguide. Each JJ responds to a pattern of current pulses by creating a corresponding pattern of voltage pulses, each with a time-integrated area related to fundamental constants as $ extit{ extbf{h/2e}}$. The pulse patterns are chosen to produce quantum-based single-tone voltage waveforms with an open-circuit voltage of 50~mV~rms (\mbox{-19.03~dBm} output power into 50~$\Omega$ load impedances) at frequencies up to 50.05~MHz, which is more than twice the voltage that has been generated by previous RF-JAWS designs at 1~GHz. The VHF-JAWS is "quantum-locked", that is, it generates one quantized output voltage pulse per input current pulse per JJ while varying the dc current through the JJ array by at least 0.4~mA and the amplitude of the bias pulses by at least 10~\%. We use the large bias pulse quantum-locking range to investigate one source of error in detail: the direct feedthrough of the current bias pulses into the DUT at VHF frequencies. We reduce this error by high-pass filtering the current bias pulses and measure the error as a function of input pulse amplitude using two techniques: by measuring small changes over the quantum-locking range and by passively attenuating the input pulse amplitude so that the nonlinear JJs no longer generate voltage pulses while the error is only linearly scaled.

This is the dataset for 4 publishable figures in 2 page abstracted titled "Josephson arbitrary waveform synthesizer for ac voltage calibrations" submitted to the Conference on Precision Electromagnetic Measurements, CPEM 2022. QLR=Quantum Locking Range.Fig. 1. QLR (2 V rms waveforms) as a function of the dc bias current offset in all 4 arrays of Bias 1.Fig. 2. QLR (2 V rms waveforms) as a function of the compensation current amplitude in all 4 arrays of Bias 1.Fig. 3. QLR (2 V rms waveform) as a function of the pulse amplitude on Bias 1 or Bias 2 high-speed current pulse channel.Fig. 4. QLR (2 V rms waveforms) as a function of the compensation current phase in all 4 arrays of Bias 1.

This is the dataset for 4 publishable figures in 2 page abstracted titled "Josephson arbitrary waveform synthesizer for ac voltage calibrations" submitted to the Conference on Precision Electromagnetic Measurements, CPEM 2022. QLR=Quantum Locking Range.Fig. 1. QLR (2 V rms waveforms) as a function of the dc bias current offset in all 4 arrays of Bias 1.Fig. 2. QLR (2 V rms waveforms) as a function of the compensation current amplitude in all 4 arrays of Bias 1.Fig. 3. QLR (2 V rms waveform) as a function of the pulse amplitude on Bias 1 or Bias 2 high-speed current pulse channel.Fig. 4. QLR (2 V rms waveforms) as a function of the compensation current phase in all 4 arrays of Bias 1.

This paper presents a 2 V programmable Josephson voltage standard with dual microwave frequency inputs and multiple output taps. The design provides three main features: (1) output voltages with nanovolt resolution, (2) the ability to perform a microwave frequency self-check based on a null voltage measurement, and (3) additional voltage output taps providing simultaneous 10:1 (or 5:1) divided voltage reference for resistive divider calibration. With low heat dissipation this device is well suited for implementation with a compact cryocooler as a turnkey traveling system.

The abstract of the paper [1] is:This paper describes differential sampling measurements of an ac source and a Josephson arbitrary waveform synthesizer (JAWS).A new iterative approach for aligning the phases of the JAWS and the source waveforms was implemented to minimize the differential voltage at the digitizer. A type-A uncertainty of 45 nV/V after 10 min was measured for a commercial ac source at 1 V rms amplitude and 1 kHz.[1] "Differential Measurements of an AC Source with a Josephson Arbitrary Waveform Synthesizer"submitted to Conference on Precision Electromagnetic Measurements (CPEM) 2024; will be published and available on IEEE website at a later date.Data for figures 2 to 4 of the manuscript.Files included in this publication: Fig 2 FFT of the digitizer signal.csv Figure 2 Fig. 2. 1 kHz component of the FFT of the digitizer signal (amplitude and phase) for Delta_V1=Source-JAWS1 and Delta_V2=Source-JAWS2 over 3.5 hours Five columns: The first column is the time (x-axis), the second column is the amplitude in volt of the first measured difference voltage (shown as black solid circle in Fig. 2), the third column is the phase in degree of the first measured difference voltage (shown as black open circle in Fig. 2), the fourth column is the amplitude in volt of the second measured difference voltage (shown as red solid circle in Fig. 2), the fifth column is the phase in degree of the second measured difference voltage (shown as red open circle in Fig. 2). Format: CSV Fig 3 Source rms amplitude and environment data.csv Figure 3 Fig. 3. Room environment conditions recorded (temperature, atmospheric pressure, and relative humidity) and Reconstructed rms amplitude for the source at 1 kHz. Five columns: The first column is the time (x-axis), the second column is the reconstructed amplitude in volt - 1 V (shown as blue solid circle in Fig. 3 bottom), the third column is the temperature in degree C (shown as orange solid square in Fig. 3 top), the fourth column is the atomsepheric pressure in hecto Pascal (shown as green open triangle in Fig. 3 top), the fifth column is the relative humidity in percent (shown as puple open circle in Fig. 2). Format: CSV Fig 4 Allan variance.csv Figure 4 Fig. 4. Allan deviation of the source amplitude measured at 1 V and 1 kHz. Five columns: The first column is the time (x-axis), the second column is the calculated Allan Deviation in volt (shown as blue solid circle in Fig. 4), the third column is the fit on the results, representing the white noise with slope -0.5 (shown as black dash line in Fig. 4), the fourth column is the is the time (x-axis) for the 1/f noise floor plot and the fifth column is the 1/f noise floor (shown as a black solid line in Fig. 4) Format: CSV

Dataset for multiple publishable figures in the paper entitled "Quasi-continuous voltage standard using sinusoidal and pulse-driven Josephson junction arrays" submitted to Meas. Sci. and Tech. journal. Figure 3. (a) Pattern of pulses used to generate a dc voltage of 0.2 V, (b) difference from the nominal of the voltage measured using the K3458A versus dc bias current for different RF power biases.Figure 4. PD JJA voltage difference from nominal, measured with a K3458A, versus dc bias current for different pulse patterns and repetition frequencies.Figure 5. (a) Current-voltage characteristic of the CWD JJA and (b) the RF power-voltage characteristic of the PD JJA. The error bars show the Type-A uncertainty (k=1) of the measurement of five measurements.Figure 6. Current-voltage characteristic of the CWD JJAs. The error bars show the Type-A uncertainty (k=1) of the measurement.Figure 7. Allan deviation for 0 V. See text for details.Figure 8. Current-voltage characteristic of the CWD JJAs. The error bars show the Type-A uncertainty (k=1) of the measurement.Figure 9. Allan deviation at 1 V.

Data sets for measuring VHF detector linearity using a Josephson Arbitrary Waveform Synthesizer (JAWS). Two instruments are measured: an RF power sensor and a fast ADC. The VHF-JAWS source consists of a chip with 12,810~Josephson junctions located in a cryocooler and driven to produce quantum-based ac waveforms at frequencies up to 50.05~MHz and power up to -19~dBm. We first confirm that the device is operating correctly by measuring the dc offset quantum-locking range (Fig. 2) and then measure the system output power with an RF power sensor (Fig. 3, bottom) and a high-speed digitizer (Fig. 3, top). After removing an overall scale factor, the ten-nanowatt scale differences between the programmed JAWS values and the measured values (Fig. 3, top and bottom) indicate better than $\pm$0.5~$\%$ DUT linearity for frequencies in the VHF band.

Data sets for measuring VHF detector linearity using a Josephson Arbitrary Waveform Synthesizer (JAWS). Two instruments are measured: an RF power sensor and a fast ADC. The VHF-JAWS source consists of a chip with 12,810~Josephson junctions located in a cryocooler and driven to produce quantum-based ac waveforms at frequencies up to 50.05~MHz and power up to -19~dBm. We first confirm that the device is operating correctly by measuring the dc offset quantum-locking range (Fig. 2) and then measure the system output power with an RF power sensor (Fig. 3, bottom) and a high-speed digitizer (Fig. 3, top). After removing an overall scale factor, the ten-nanowatt scale differences between the programmed JAWS values and the measured values (Fig. 3, top and bottom) indicate better than $\pm$0.5~$\%$ DUT linearity for frequencies in the VHF band.