Josephson Voltage Source Calibration for Adjustable Quantum Accuracy

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Solution Overview

Problem

High-accuracy voltage sources based on the AC Josephson effect lack continuous and fine voltage adjustment capabilities, limiting their use in applications requiring arbitrary signal generation, and conventional adjustable voltage sources suffer from low accuracy and residual discretization, hindering performance improvements in fields like mesoscopic physics and quantum computing.

Innovation Solution

An electrical voltage source with an integrated circuit, Josephson junctions, and a cryogenic module, coupled with a microwave generator and an adjustment module that adjusts the amplitude of the control signal as a function of its frequency according to a predetermined rule, enabling stable voltage adjustment across a wide frequency band with high resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional voltage sources are used, then ease of operation is improved, but measurement precision deteriorates

Engineering Contradiction:
ImproveadjustabilityVSAvoidvoltage accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the operating parameters by using a Josephson junction operated in its superconducting state with microwave irradiation. The output voltage is determined by the frequency of the microwave signal according to the relationship V = n(hf/2e), where n is an integer. This allows continuous adjustment of the output voltage by varying the microwave frequency while maintaining metrological accuracy through the fundamental quantum relationship.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic adjustment capability by allowing continuous variation of the microwave frequency controlling the Josephson junction. This enables the voltage source to be tuned across a wide frequency band (e.g., 4-20 GHz) with fine resolution, transforming the static voltage output of conventional sources into a dynamically adjustable signal while preserving accuracy.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If PJVS-type sources are used, then measurement precision is improved, but adaptability deteriorates

Engineering Contradiction:
Improvevoltage accuracyVSAvoidsignal generation capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent achieves multi-functionality by combining the metrological accuracy of Josephson voltage standards with the signal generation capability of function generators. The device can operate in multiple modes: providing stable DC voltages with quantum accuracy, generating arbitrary time-varying signals with controlled amplitude and frequency, and operating across a wide frequency band. This universal capability allows the same device to serve both as a voltage standard and as a signal source for various applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If JAWS-type sources are used, then adaptability is improved, but measurement precision deteriorates

Engineering Contradiction:
Improvewaveform generation capabilityVSAvoidvoltage accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent introduces a calibration intermediary process that uses the quantum-accurate Josephson junction to establish a precise frequency-voltage relationship. By measuring the output voltage of the Josephson junction at known microwave frequencies and using this calibration data to correct or adjust subsequent measurements and signal generations, the system achieves both high adaptability and metrological accuracy. The calibration process acts as a mediator that transfers the quantum accuracy to the adjustable signal generation function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides adjustable voltages with metrological accuracy, allowing for stable output voltage adjustments across a wide frequency band, enhancing the performance of electronic devices in fields like mesoscopic physics and quantum computing by overcoming the limitations of existing high-accuracy voltage sources.

Implementation Method 1

These voltage sources, whose operation is based on the AC Josephson effect, make it possible to provide an electrical voltage with a very high accuracy

Methodology Applied
Scientific EffectAC Josephson effect: Josephson Effect

Implementation Method 2

a cryogenic module configured to maintain the integrated circuit in conditions in which the integrated circuit is in a superconducting state

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentUS20230341880A1Voltage source and method for calibrating this voltage source
Publication Date: 2023.10.26 PARIS SCI & LETTRES
  • US20230341880A1 patent drawing
  • US20230341880A1 patent drawing
  • US20230341880A1 patent drawing

AI summary

Embodiments of the present disclosure provide a pixel circuitry, a drive method thereof, an array substrate and a display panel. The pixel circuitry includes circuits designated: drive CD, data write CDW, initialization CI, first light emission control CLEC1, first storage CS1, second storage CS2 and second light emission control CLEC2. CD connects to first through third nodes N1-N3 and provides drive current to a light emitting device. CDW connects to N1 and provides a data signal to CD according to a drive signal. CI provides an initialization signal to N2 according to a reset signal. CLEC1 provides a first voltage signal to N3 according to a first light emission control signal. CS1 and CS2 store a voltage difference between the first voltage signal terminal and N2, and N1 and N2, respectively. CLEC2 controls the drive current to the light emitting device according to a second light emission control signal.