Josephson Junction Quantum Amplifier Circuit Topology

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Solution Overview

Problem

Conventional amplifiers introduce excessive noise and are unsuitable for quantum circuits due to their dissipative nature, limiting their ability to amplify quantum signals effectively without degrading the signal-to-noise ratio.

Innovation Solution

A quantum circuit design featuring Josephson junctions arranged in series within sub-circuits, with multiple sub-circuits connected in parallel, incorporating capacitors and inductors to enhance dynamic range and minimize noise, allowing for efficient amplification of quantum signals while maintaining sensitivity to low energies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional amplifiers are used to amplify quantum signals, then the signal energy is increased to exceed electronic noise, but excessive noise is introduced and sensitivity to low energies is poor

Engineering Contradiction:
Improvesignal energyVSAvoidnoise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent replaces conventional dissipative electronic amplifiers with a quantum circuit amplifier based on Josephson junctions. This substitution transitions from a classical electronic system to a quantum mechanical system that operates without dissipation, thereby eliminating the generation of excess noise while maintaining amplification capability. The quantum circuit uses quantum mechanical phenomena to amplify signals without the harmful side effects of conventional amplifiers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental operating parameters of the amplifier by using Josephson junctions with specific critical currents and junction parameters tailored for quantum operation. By operating at quantum energy scales and using non-dissipative quantum circuit elements, the amplifier achieves high sensitivity to low energies while maintaining low noise output, resolving the contradiction between signal amplification and noise generation.

Inventive Principle:
Principle #35Parameter changes

2Power

If conventional amplifiers are used, then signal amplification is achieved, but the amplification degrades the signal-to-noise ratio

Engineering Contradiction:
Improvesignal amplificationVSAvoidsignal-to-noise ratio
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The patent replaces conventional dissipative amplifiers with a quantum circuit amplifier based on Josephson junctions. This substitution transitions from a classical electronic system to a quantum mechanical system that operates without dissipation, thereby eliminating the generation of excess noise while maintaining amplification capability. The quantum circuit uses quantum mechanical phenomena to amplify signals without the harmful side effects of conventional amplifiers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If quantum circuit elements are used, then sensitivity to low energies is improved, but device complexity increases

Engineering Contradiction:
Improvesensitivity to low energiesVSAvoidcircuit structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the quantum amplifier into multiple identical Josephson junctions arranged in a specific circuit configuration. Each junction operates as a modular unit with well-defined quantum parameters. This segmentation allows the system to achieve high sensitivity through the collective behavior of multiple junctions while maintaining manufacturability through repetition of identical elements. The modular structure facilitates both quantum operation and practical fabrication.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the fundamental operating parameters of the amplifier by using Josephson junctions with specific critical currents and junction parameters tailored for quantum operation. By operating at quantum energy scales and using non-dissipative quantum circuit elements, the amplifier achieves high sensitivity to low energies while maintaining low noise output, resolving the contradiction between signal amplification and noise generation.

Inventive Principle:
Principle #35Parameter changes

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 proposed quantum amplifier achieves a higher dynamic range and improved signal amplification with reduced noise, enabling the amplification of quantum signals without introducing excessive noise, thus overcoming the limitations of conventional amplifiers.

Implementation Method 1

the quantum circuit elements are Josephson junctions

Methodology Applied
Scientific EffectJosephson effect: Josephson Effect

Data Source

PatentEP3262697B1Techniques for producing quantum amplifiers and related systems and methods
Publication Date: 2021.10.13 YALE UNIVERSITY
  • EP3262697B1 patent drawingFigure 1
  • EP3262697B1 patent drawingFigure 2
  • EP3262697B1 patent drawingFigure 3

AI summary

According to some aspects, a quantum circuit is provided including a plurality of non-linear circuit elements coupled together in series and in parallel, such that at least two of the circuit elements are coupled together in series and at least two of the circuit elements are coupled together in parallel, wherein the quantum circuit is configured to act as an amplifier.