Ultimate squeezing through coherent quantum feedback
Coherent feedback is the use of feedback loops not involving any measurements for the purpose of quantum control. This can be contrasted to measurement-based feedback where the feedback signal is directed by the result of measurements upon the system. Here, we develop a general framework to describe...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-10-01
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| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.2.043103 |
| _version_ | 1797211235999023104 |
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| author | Alfred Harwood Alessio Serafini |
| author_facet | Alfred Harwood Alessio Serafini |
| author_sort | Alfred Harwood |
| collection | DOAJ |
| description | Coherent feedback is the use of feedback loops not involving any measurements for the purpose of quantum control. This can be contrasted to measurement-based feedback where the feedback signal is directed by the result of measurements upon the system. Here, we develop a general framework to describe interferometric coherent feedback loops and prove that, under any such scheme, the steady-state squeezing of a bosonic mode subject to a rotating wave coupling with a white-noise environment and to any quadratic Hamiltonian must abide by a noise-dependent bound that reduces to the 3-dB limit at zero temperature. Such a finding is compared, at fixed dynamical parameters, with the performance of homodyne continuous monitoring of the output modes, which allows one to beat coherent feedback and the 3-dB limit under certain dynamical conditions. |
| first_indexed | 2024-04-24T10:23:16Z |
| format | Article |
| id | doaj.art-e1a47a12102f4942a5f53f42fcf8ba7a |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:23:16Z |
| publishDate | 2020-10-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-e1a47a12102f4942a5f53f42fcf8ba7a2024-04-12T17:02:43ZengAmerican Physical SocietyPhysical Review Research2643-15642020-10-012404310310.1103/PhysRevResearch.2.043103Ultimate squeezing through coherent quantum feedbackAlfred HarwoodAlessio SerafiniCoherent feedback is the use of feedback loops not involving any measurements for the purpose of quantum control. This can be contrasted to measurement-based feedback where the feedback signal is directed by the result of measurements upon the system. Here, we develop a general framework to describe interferometric coherent feedback loops and prove that, under any such scheme, the steady-state squeezing of a bosonic mode subject to a rotating wave coupling with a white-noise environment and to any quadratic Hamiltonian must abide by a noise-dependent bound that reduces to the 3-dB limit at zero temperature. Such a finding is compared, at fixed dynamical parameters, with the performance of homodyne continuous monitoring of the output modes, which allows one to beat coherent feedback and the 3-dB limit under certain dynamical conditions.http://doi.org/10.1103/PhysRevResearch.2.043103 |
| spellingShingle | Alfred Harwood Alessio Serafini Ultimate squeezing through coherent quantum feedback Physical Review Research |
| title | Ultimate squeezing through coherent quantum feedback |
| title_full | Ultimate squeezing through coherent quantum feedback |
| title_fullStr | Ultimate squeezing through coherent quantum feedback |
| title_full_unstemmed | Ultimate squeezing through coherent quantum feedback |
| title_short | Ultimate squeezing through coherent quantum feedback |
| title_sort | ultimate squeezing through coherent quantum feedback |
| url | http://doi.org/10.1103/PhysRevResearch.2.043103 |
| work_keys_str_mv | AT alfredharwood ultimatesqueezingthroughcoherentquantumfeedback AT alessioserafini ultimatesqueezingthroughcoherentquantumfeedback |