Active-feedback quantum control of an integrated low-frequency mechanical resonator

Abstract

Preparing a massive mechanical resonator in a state with quantum limited motional energy provides a promising platform for studying fundamental physics with macroscopic systems and allows to realize a variety of applications, including precise sensing. While several demonstrations of such ground-state cooled systems have been achieved, in particular in sideband-resolved cavity optomechanics, for many systems overcoming the heating from the thermal bath remains a major challenge. In contrast, optomechanical systems in the sideband-unresolved limit are much easier to realize due to the relaxed requirements on their optical properties, and the possibility to use a feedback control schemes to reduce the motional energy. The achievable thermal occupation is ultimately limited by the correlation between the measurement precision and the back-action from the measurement. Here, we demonstrate measurement-based feedback cooling on a fully integrated optomechanical device fabricated using a pick-and-place method, operating in the deep sideband-unresolved limit. With the large optomechanical interaction and a low thermal decoherence rate, we achieve a minimal average phonon occupation of 0.76 when pre-cooled with liquid helium and 3.5 with liquid nitrogen. Significant sideband asymmetry for both bath temperatures verifies the quantum character of the mechanical motion. Our method and device are ideally suited for sensing applications directly operating at the quantum limit, greatly simplifying the operation of an optomechanical system in this regime.

References in corpus (20)

• Sideband Cooling Micromechanical Motion to the Quantum Ground State
• Motional Quantum Ground State of a Levitated Nanoparticle from Room Temperature
• Ground-state cooling of a micromechanical oscillator: generalized framework for cold damping and cavity-assisted cooling schemes
• Opto-mechanical transducers for long-distance quantum communication
• Real-time optimal quantum control of mechanical motion at room temperature
• Quantum control of a nanoparticle optically levitated in cryogenic free space
• Sideband Cooling Beyond the Quantum Limit with Squeezed Light
• Entanglement-Enhanced Optomechanical Sensing
• Approaching the motional ground state of a 10 kg object
• Converting microwave and telecom photons with a silicon photonic nanomechanical interface
• Optomechanical ground-state cooling in a continuous and efficient electro-optic transducer
• Membrane-based scanning force microscopy
• Quantum sensing with nanoparticles for gravimetry; when bigger is better
• Fractal-like mechanical resonators with soft-clamped fundamental mode
• Tuning the effective coupling of an AFM lever to a thermal bath
• Heterodyne photodetection measurements on cavity optomechanical systems: Interpretation of sideband asymmetry and limits to a classical explanation
• Efficient entanglement of spin qubits mediated by a hot mechanical oscillator
• Integrated optical-readout of a high-Q mechanical out-of-plane mode
• Imaging correlations in heterodyne-detected spectra for quantum sensing
• Coherent feedback in optomechanical systems in the sideband-unresolved regime

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