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Superconducting quantum interference device readout circuit with tunable feedback polarity
Xinyu Wu1, Jianshe Liu1, Wei Chen1,2,3
1Laboratory of Superconducting Quantum Information Processing, School of Integrated Circuits, Tsinghua University, Beijing 100084, People's Republic of China.
The Review of Scientific Instruments
|September 28, 2023
Summary
This study introduces a tunable feedback polarity (TFP) circuit for superconducting quantum interference device (SQUID) readout. This innovation enhances SQUID performance and enables compact, versatile SQUID electronics.
Area of Science:
- Superconducting electronics
- Quantum device readout
Background:
- Feedback circuits are crucial for high-performance superconducting quantum interference device (SQUID) readout.
- Positive feedback suppresses noise, while negative feedback expands the linear flux range.
- Integrating diverse feedback functions onto a single SQUID chip is key for compact SQUID electronics.
Purpose of the Study:
- To propose a novel SQUID readout circuit with tunable feedback polarity (TFP).
- To enable easy switching of feedback polarity using integrated superconducting switches.
- To develop a compact and versatile SQUID readout architecture.
Main Methods:
- Implementation of a SQUID readout circuit with integrated superconducting switches for polarity control.
- Application of a control current to switch feedback polarity.
- Introduction of a two-stage scheme to mitigate noise degradation from negative feedback.
Main Results:
- The tunable feedback polarity (TFP) circuit allows for easy switching between positive and negative feedback.
- The choice of feedback polarity directly influences the enhancement of the flux-to-voltage transfer coefficient or linear flux range.
- The two-stage scheme effectively addresses noise performance issues associated with negative feedback.
Conclusions:
- The proposed TFP SQUID readout circuit offers enhanced performance and versatility.
- This architecture facilitates the development of highly compact SQUID electronics.
- The use of compatible superconducting technologies ensures a robust and adaptable design for advanced SQUID applications.
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