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Active-feedback quantum control of an integrated low-frequency mechanical resonator
Jingkun Guo1, Jin Chang1, Xiong Yao1,2,3
1Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ, Delft, The Netherlands.
Nature Communications
|August 5, 2023
Summary
Researchers achieved quantum-limited cooling in optomechanical systems using measurement-based feedback. This breakthrough simplifies achieving quantum-limited sensing with massive mechanical resonators, overcoming thermal bath challenges.
Area of Science:
- Quantum physics
- Optomechanics
- Macroscopic quantum phenomena
Background:
- Quantum-limited cooling of massive mechanical resonators is crucial for fundamental physics and precise sensing.
- Achieving ground-state cooling in optomechanics is challenging due to thermal bath heating.
- Sideband-unresolved optomechanical systems offer easier realization and feedback control possibilities.
Purpose of the Study:
- To demonstrate measurement-based feedback cooling in a fully integrated optomechanical device operating in the deep sideband-unresolved limit.
- To achieve quantum-limited motional energy in a macroscopic mechanical resonator.
- To simplify the operation of optomechanical systems for quantum-limited sensing applications.
Main Methods:
- Fabrication of an integrated optomechanical device using a pick-and-place method.
- Implementation of measurement-based feedback cooling in the deep sideband-unresolved regime.
- Operation and characterization of the device at liquid helium and liquid nitrogen temperatures.
Main Results:
- Achieved a minimal average phonon occupation of 0.76 (liquid helium) and 3.5 (liquid nitrogen).
- Demonstrated significant sideband asymmetry, verifying the quantum nature of mechanical motion.
- Showcased the effectiveness of feedback cooling in overcoming thermal decoherence.
Conclusions:
- Measurement-based feedback cooling is a viable method for achieving quantum-limited motional states in sideband-unresolved optomechanical systems.
- The developed integrated device simplifies the operation of optomechanical systems for quantum-limited sensing.
- This approach paves the way for practical quantum sensing applications using macroscopic mechanical resonators.
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