Josephson Parametric Converter Directional Amplifier Noise Suppression

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Solution Overview

Problem

Conventional microwave amplifiers for detecting low levels of microwave radiation are limited by reciprocity, which allows noise from room temperature circuitry to interfere with low-temperature superconducting qubits, and ferrite-based non-reciprocal components are bulky and detrimental to superconducting devices.

Innovation Solution

A low-noise directional amplifier is developed using Josephson Parametric Converters (JPCs) with phase-sensitive active non-reciprocity, where the phase difference between pump signals creates non-reciprocal behavior without magnetic fields, allowing for integrated circuit implementation and minimal noise amplification at the quantum limit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional microwave amplifiers are used for detecting low levels of microwave radiation, then amplification is achieved, but noise from room temperature circuitry interferes with low-temperature superconducting qubits due to reciprocity

Engineering Contradiction:
Improvedetection sensitivityVSAvoidnoise feedback
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces conventional ferrite-based non-reciprocal components with Josephson Parametric Converters (JPCs) that utilize quantum mechanical effects. The JPCs employ parametric amplification with phase-sensitive detection to achieve non-reciprocal noise suppression without requiring bulky ferrite materials or magnetic fields, thereby protecting superconducting qubits from noise feedback while maintaining detection sensitivity

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

Solution Approach 2:

The patent changes the operational parameters by using phase-dependent parametric amplification in JPCs. By controlling the phase relationship between pump signals and signal waves, the system achieves directionality and noise suppression. The reflection gain amplitude and transmission gain amplitude are tuned to specific ranges to optimize noise rejection while maintaining signal amplification

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If ferrite-based non-reciprocal components are used to block noise, then noise feedback is reduced, but the components are bulky and detrimental to superconducting devices

Engineering Contradiction:
Improvenoise feedbackVSAvoidcomponent size
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent substitutes ferrite-based electromagnetic components with superconducting Josephson junction-based devices. The JPCs utilize quantum tunneling and parametric resonance effects to achieve non-reciprocal behavior, eliminating the need for bulky ferrite materials and external magnetic fields. This integration enables compact, chip-scale implementations compatible with superconducting qubit architectures

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

Solution Approach 2:

The patent employs composite superconducting structures combining Josephson junctions with resonant circuits and transmission lines. These composite elements create non-reciprocal behavior through the interplay of superconducting properties and circuit dynamics, achieving noise suppression in a compact form factor that is integrated with superconducting qubits

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If ferrite-based non-reciprocal components are used to achieve non-reciprocity, then noise feedback is reduced, but magnetic fields harm superconducting devices

Engineering Contradiction:
Improvenoise feedbackVSAvoidmagnetic field interference
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent replaces ferrite-based magnetic field mechanisms with Josephson junction-based quantum mechanical mechanisms. The non-reciprocal noise suppression is achieved through phase-sensitive parametric amplification and quantum interference effects in the JPCs, completely eliminating the need for external magnetic fields that would otherwise harm the superconducting qubits

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

Solution Approach 2:

The patent introduces the JPC as an intermediary device between the signal source and the superconducting qubits. The JPC performs phase-dependent parametric amplification and noise filtering, mediating the interaction between the measurement system and the qubits while protecting them from harmful magnetic fields and noise feedback

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 amplifier effectively reduces noise feedback to superconducting qubits, enabling efficient quantum state measurement and amplification at or near the quantum noise limit, allowing for observation of quantum jumps without ferrite-based elements.

Implementation Method 1

low-noise directional amplifier uses Josephson Parametric Converters (JPCs) with phase-sensitive active non-reciprocity

Methodology Applied
Scientific EffectJosephson effect: Josephson Effect

Data Source

PatentEP3058618B1Low-noise josephson junction-based directional amplifier
Publication Date: 2020.09.02 YALE UNIVERSITY
  • EP3058618B1 patent drawingFigure 1
  • EP3058618B1 patent drawingFigure 2
  • EP3058618B1 patent drawingFigure 3

AI summary

A low-noise directional amplifier includes a first port, a second port, a first coupler and a second coupler. The first port is coupled to a first coupler. The low-noise directional amplifier also includes at least two phase preserving amplifiers, a first phase preserving amplifier connected to the first coupler and a second coupler, and the second phase preserving amplifier connected to the first coupler and the second coupler.