Print Email Facebook Twitter Active-feedback quantum control of an integrated low-frequency mechanical resonator Title Active-feedback quantum control of an integrated low-frequency mechanical resonator Author Guo, J. (TU Delft QN/Groeblacher Lab; Kavli institute of nanoscience Delft) Chang, J. (TU Delft QN/Groeblacher Lab; Kavli institute of nanoscience Delft) Yao, X. (TU Delft QN/Groeblacher Lab; Fudan University; Westlake University, Hangzhou) Groeblacher, S. (TU Delft QN/Groeblacher Lab; Kavli institute of nanoscience Delft) Date 2023 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. Subject OA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:e21490c0-d7b7-4b79-a4bb-c04c674f1ecd DOI https://doi.org/10.1038/s41467-023-40442-3 ISSN 2041-1723 Source Nature Communications, 14 (1) Part of collection Institutional Repository Document type journal article Rights © 2023 J. Guo, J. Chang, X. Yao, S. Groeblacher Files PDF s41467_023_40442_3.pdf 2.78 MB Close viewer /islandora/object/uuid:e21490c0-d7b7-4b79-a4bb-c04c674f1ecd/datastream/OBJ/view