High-Tc Cuprate SNSPD for Liquid Nitrogen Cooling

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Solution Overview

Problem

Conventional Superconducting Nanowire Single-Photon Detectors (SNSPDs) are limited to ultra-low operation temperatures, making them impractical and expensive for practical applications due to the use of low-quality superconducting materials and sputtering processes, which restrict their operation to cryogenic refrigerators.

Innovation Solution

A SNSPD using high-Tc cuprate superconductor materials with a critical temperature above 77 K, allowing operation with liquid nitrogen cooling, and encapsulated in air-impenetrable van der Waals materials to prevent oxidation, enabling wider practical applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional low-quality superconducting materials and sputtering processes are used, then the detector can be manufactured with existing technology, but it can only operate at ultra-low temperatures requiring large cryogenic refrigerators

Engineering Contradiction:
Improveoperation temperatureVSAvoidcryogenic refrigerator system
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent changes the fundamental material parameter by using high-Tc cuprate superconductors (such as YBCO, BSCCO, Tl-2223, or Hg-1201) with critical temperatures above 77K, enabling operation with liquid nitrogen cooling instead of requiring complex cryogenic refrigerator systems. This material parameter change directly resolves the contradiction between operating temperature and device complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures combining high-Tc cuprate superconductors with protective encapsulation layers (such as hexagonal boron nitride or other inert materials) to prevent oxidation. This composite approach enables the thin superconducting nanowire to operate at elevated temperatures while maintaining superconducting properties, avoiding the need for bulky cryogenic systems.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If the superconducting nanowire is made thin to improve photon detection efficiency, then quantum efficiency improves, but the material degrades due to oxidation when exposed to air

Engineering Contradiction:
Improvephoton detection efficiencyVSAvoidmaterial stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent uses ultra-thin encapsulation films (such as hexagonal boron nitride layers) that are transparent to photons but impermeable to oxygen and water. These thin film encapsulations protect the superconducting nanowire from oxidation while maintaining photon detection efficiency, resolving the contradiction between thinness for detection and protection for reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent creates an inert protective environment around the superconducting nanowire using encapsulation materials that prevent exposure to oxidizing atmospheric conditions. This inert environment allows the thin nanowire to maintain both its detection efficiency and material stability simultaneously.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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

This solution enables SNSPDs to operate at elevated temperatures up to 120 K, reducing costs and complexity, improving quantum efficiency, and allowing integration into various photonics platforms, enhancing detectivity and reliability while maintaining high precision and uniformity.

Implementation Method 1

the superconducting nanowire or nanostrip is made of a high-Tc cuprate superconductor material having a superconducting critical temperature above 77 K

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Implementation Method 2

Based on local heating and hot spot creation in ultra-thin superconducting (SC) nanowires

Methodology Applied
Scientific EffectLocal heating and hot spot creation: Heating

Implementation Method 3

encapsulated in air-impenetrable van der Waals materials to prevent oxidation

Methodology Applied
Scientific EffectOxidation prevention: Oxidation

Data Source

PatentEP3795961B1A superconducting nanowire single-photon detector, and a method for obtaining such detector
Publication Date: 2023.09.06 FUNDACIO INST DE CIENCIES FOT NIQUES
  • EP3795961B1 patent drawingFigure 1~2
  • EP3795961B1 patent drawingFigure 3~4
  • EP3795961B1 patent drawingFigure 5~6d

AI summary

The present invention relates to a superconducting nanowire single-photon detector, comprising a superconducting nanowire configured and arranged for the incidence of a photon on a region thereof and the formation, on that region, of a localized non-superconducting region or hotspot. The superconducting nanowire is made of a high-Tc cuprate superconductor material having a superconducting critical temperature above 77 K. The present invention also relates to a method for obtaining the superconducting nanowire single-photon detector of the present invention.