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Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
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Quantum mechanics-free subsystem with mechanical oscillators.
Laure Mercier de Lépinay1, Caspar F Ockeloen-Korppi1, Matthew J Woolley2
1QTF Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland.
Science (New York, N.Y.)
|May 7, 2021
Summary
Researchers developed a quantum mechanics-free subsystem using two micromechanical oscillators to bypass quantum back-action during oscillator measurement. This breakthrough enhances precision for detecting weak forces and generating nonclassical states.
Area of Science:
- Quantum mechanics
- Quantum optics
- Optomechanics
Background:
- Quantum mechanics imposes fundamental limits on measurement precision.
- Continuous measurement of an oscillator's position is subject to quantum back-action.
- Detecting weak forces and generating nonclassical states are challenging due to these limits.
Purpose of the Study:
- To demonstrate a method for measuring an oscillator while circumventing quantum back-action.
- To realize a quantum mechanics-free subsystem using coupled micromechanical oscillators.
- To verify the effectiveness of this subsystem in reducing measurement noise and confirming quantum entanglement.
Main Methods:
- Constructing an effective oscillator from two coupled physical micromechanical oscillators.
- Performing measurements of collective quadratures of the coupled system.
- Quantifying quantum back-action evasion and entanglement using the Duan quantity.
Main Results:
- Achieved quantum mechanics-free measurement by evading quantum back-action by 8 decibels on collective quadratures.
- Obtained total noise within a factor of 2 of the full quantum limit.
- Directly verified quantum entanglement between the two oscillators, with the Duan quantity 1.4 decibels below the separability bound.
Conclusions:
- The developed quantum mechanics-free subsystem effectively reduces measurement back-action.
- This technique facilitates enhanced detection of weak forces and generation/measurement of nonclassical motional states.
- The verified quantum entanglement opens avenues for advanced quantum information processing and metrology.
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