Superconducting Junction Thermal Control for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Superconducting-Insulator-Superconducting (S-I-S) junctions in measurement devices suffer from low-frequency noise due to temperature fluctuations, and existing methods to protect against flux-trapping in high transient magnetic fields, such as heating, result in slow recovery from a non-superconducting state, making them impractical.
Innovation Solution
A superconducting junction with a layer of thermally conducting non-superconducting material between two superconducting layers, allowing for rapid temperature control between superconducting and non-superconducting states through a temperature controlling element and heating/cooling systems, which stabilizes or varies the temperature effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the area of the Josephson junction is made large to average out temperature fluctuations, then low-frequency noise is reduced, but flux-trapping becomes more prone
Solution Approach 1:
The patent divides the superconducting junction into multiple smaller superconducting regions separated by insulating barriers. This segmentation allows each region to be small enough to avoid flux-trapping while the collective array provides sufficient averaging to reduce low-frequency noise, thus resolving the contradiction between noise reduction and flux-trapping prevention.
2Object-affected harmful factors
If heating is applied to protect SQUID from high transient magnetic field, then flux-trapping is prevented, but recovery from non-superconducting state becomes slow
Solution Approach 1:
The patent implements dynamic thermal control by applying heating pulses only during high transient magnetic field events rather than continuous heating. This allows the SQUID to remain in superconducting state during normal operation for fast recovery, while temporarily transitioning to non-superconducting state only when protection is needed, thus resolving the contradiction between protection and recovery speed.
Solution Approach 2:
The patent uses periodic or pulsed heating applied in sync with transient magnetic field events. This periodic action provides protection during high field events while allowing the system to return to superconducting state between pulses, maintaining fast recovery capability while preventing flux-trapping when necessary.
3Reliability
If heating is used to protect against high transient magnetic field, then flux traps are prevented, but the protection method becomes impractical due to slow recovery
Solution Approach 1:
The patent transitions from static continuous heating to dynamic pulsed heating controlled by detection of transient field events. This dynamic approach maintains reliability by providing protection when needed while restoring productivity by enabling fast recovery during normal operation, thus resolving the contradiction between reliability and productivity.
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
Enables fast and controlled switching between superconducting and non-superconducting states, reducing thermal inertia and alleviating low-frequency noise, thus improving the performance of S-I-S junctions in devices like SQUID magnetometers and MRI machines.
Implementation Method 1
a layer of thermally conducting non-superconducting material between two superconducting layers
Implementation Method 2
allowing for rapid temperature control between superconducting and non-superconducting states through a temperature controlling element and heating/cooling systems
Implementation Method 3
allowing for rapid temperature control between superconducting and non-superconducting states through a temperature controlling element and heating/cooling systems
Data Source
AI summary
A superconducting junction comprises: a first layer and a second layer of superconducting material; a tunneling layer of insulating material disposed between the first layer and the second layer of the superconducting material; and a layer of thermally conducting, non-superconducting material disposed between the first layer and the second layer of the superconducting material, the non-superconducting layer being in contact with either the first layer or the second layer of superconducting material.