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Phase-preserving amplification near the quantum limit with a Josephson ring modulator
N Bergeal1, F Schackert, M Metcalfe
1Department of Physics and Applied Physics, Yale University, New Haven, Connecticut 06520-8284, USA. nicolas.bergeal@espci.fr
Nature
|May 7, 2010
Summary
Researchers developed a novel superconducting parametric amplifier that preserves phase information, crucial for quantum information processing. This phase-preserving amplifier achieves near quantum-limited noise performance, opening new avenues for quantum technologies.
Area of Science:
- Quantum Information Processing
- Superconducting Devices
- Microwave Amplifiers
Background:
- Solid-state quantum information processing requires quantum-limited amplifiers and frequency converters.
- Linear amplifiers are classified as phase-sensitive or phase-preserving, with different noise properties.
- Phase-preserving amplifiers are highly desirable but have been unavailable.
Purpose of the Study:
- To experimentally realize an intrinsically phase-preserving superconducting parametric amplifier.
- To demonstrate a device with quantum-limited performance for microwave signals.
- To enable new applications in quantum analog signal processing.
Main Methods:
- Utilized a Josephson ring modulator with four Josephson junctions in a Wheatstone bridge configuration.
- Implemented a non-degenerate parametric amplification scheme.
- Characterized the amplifier's gain, bandwidth, and noise properties using a novel noise source.
Main Results:
- Successfully realized a phase-preserving superconducting parametric amplifier.
- Achieved gain and bandwidth characteristics in agreement with analytical predictions.
- Demonstrated a total system noise upper bound of three times the quantum limit under operating conditions.
Conclusions:
- The developed Josephson ring modulator amplifier is intrinsically phase-preserving.
- The device offers a significant advancement for quantum analog signal processing applications.
- Potential applications include quantum non-demolition readout, quantum feedback, and entangled microwave pair generation.
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