Superconducting Loop Amplifier With Flux-Tuned Josephson Current
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Solution Overview
Problem
Existing superconducting components, such as SQUID circuits, do not allow for precise control of the critical current of Josephson junctions, which limits their performance in applications like amplifiers and sensing devices.
Innovation Solution
A superconducting component with a first superconducting loop containing a first Josephson junction and a second branch with a direct current quantum interference superconducting device, where the critical current of the first Josephson junction is adjustable by controlling the magnetic flux, allowing for precise adjustment of the critical current of the Josephson junctions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional SQUID circuits are used, then superconducting component functionality is achieved, but precise control of critical current is not possible
Solution Approach 1:
The device is divided into two separate branches: a first branch containing a first Josephson junction, and a second branch containing a DC SQUID with second and third Josephson junctions. This segmentation allows independent control of critical currents in different parts of the circuit, enabling precise adjustment of the first junction's critical current through magnetic flux applied to the DC SQUID branch without affecting the overall device functionality.
Solution Approach 2:
The DC SQUID acts as an intermediary device that translates magnetic flux control into critical current adjustment. By applying magnetic flux to the DC SQUID, the critical current of the first Josephson junction can be precisely controlled through the relationship defined by the triangle inequality, without requiring direct control mechanisms on the first junction itself.
2Reliability
If critical current control is added to Josephson junctions, then performance in amplifiers and sensing devices is improved, but device complexity increases
Solution Approach 1:
The DC SQUID serves multiple functions: it acts as a control element for adjusting the critical current of the first Josephson junction, while also functioning as an active component in the superconducting circuit. This multi-functionality allows critical current control to be achieved without adding separate control mechanisms, thereby improving reliability in amplifier and sensing applications without proportionally increasing complexity.
3Adaptability or versatility
If magnetic flux control is implemented, then critical current adjustment is enabled, but control mechanism complexity increases
Solution Approach 1:
The critical current of the first Josephson junction is controlled by changing the magnetic flux parameter applied to the DC SQUID. This parameter change approach allows continuous adjustment of the critical current within the bounds defined by the triangle inequality (|Ic2 - Ic3| < Ic1 < Ic2 + Ic3), providing adaptability without requiring complex mechanical or electrical control mechanisms.
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 better control over the critical current of the Josephson junctions, enhancing the performance of superconducting components, particularly in amplifier circuits by allowing for maximum modulation amplitude and improved matching of Josephson junctions.
Implementation Method 1
the Josephson effect is manifested by the appearance of a current, also called supercurrent, between two superconducting materials separated by a non-superconducting layer
Implementation Method 2
below the superconducting transition temperature, at least some of the free electrons in the superconducting material are bonded together, so as to form pairs of electrons called 'Cooper pairs'
Implementation Method 3
the means for generating magnetic flux being arranged so as to effectively inject a magnetic flux into the first superconducting loop and the first device DC quantum interference superconductor
Implementation Method 4
a first direct current quantum interference superconducting device, the first direct current quantum interference superconducting device having a second Josephson junction and a third Josephson junction
Data Source
Figure 1~2
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AI summary
The invention concerns a superconducting component (10) comprising a first superconducting loop (12), the first superconducting loop (12) comprising: • a first branch (20) comprising a first Josephson junction (32), • a second branch (22). The second branch (22) comprises a first DC superconducting quantum interference device (38).