Enhancement of low-temperature thermometry by strong coupling
We consider the problem of estimating the temperature T of a very cold equilibrium sample. The temperature estimates are drawn from measurements performed on a quantum Brownian probe strongly coupled to it. We model this scenario by resorting to the canonical Caldeira-Leggett Hamiltonian and find an...
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| Format: | Article |
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American Physical Society
2017
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| Online Access: | https://eprints.nottingham.ac.uk/48572/ |
| _version_ | 1848797796886380544 |
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| author | Correa, Luis A. Perarnau-Llobet, Martí Hovhannisyan, Karen V. Mehboudi, Mohammad Hernández-Santana, Senaida Sanpera, Anna |
| author_facet | Correa, Luis A. Perarnau-Llobet, Martí Hovhannisyan, Karen V. Mehboudi, Mohammad Hernández-Santana, Senaida Sanpera, Anna |
| author_sort | Correa, Luis A. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We consider the problem of estimating the temperature T of a very cold equilibrium sample. The temperature estimates are drawn from measurements performed on a quantum Brownian probe strongly coupled to it. We model this scenario by resorting to the canonical Caldeira-Leggett Hamiltonian and find analytically the exact stationary state of the probe for arbitrary coupling strength. In general, the probe does not reach thermal equilibrium with the sample, due to their nonperturbative interaction. We argue that this is advantageous for low-temperature thermometry, as we show in our model that (i) the thermometric precision at low T can be significantly enhanced by strengthening the probe-sampling coupling, (ii) the variance of a suitable quadrature of our Brownian thermometer can yield temperature estimates with nearly minimal statistical uncertainty, and (iii) the spectral density of the probe-sample coupling may be engineered to further improve thermometric performance. These observations may find applications in practical nanoscale thermometry at low temperatures—a regime which is particularly relevant to quantum technologies. |
| first_indexed | 2025-11-14T20:09:35Z |
| format | Article |
| id | nottingham-48572 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T20:09:35Z |
| publishDate | 2017 |
| publisher | American Physical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-485722020-05-04T19:21:06Z https://eprints.nottingham.ac.uk/48572/ Enhancement of low-temperature thermometry by strong coupling Correa, Luis A. Perarnau-Llobet, Martí Hovhannisyan, Karen V. Mehboudi, Mohammad Hernández-Santana, Senaida Sanpera, Anna We consider the problem of estimating the temperature T of a very cold equilibrium sample. The temperature estimates are drawn from measurements performed on a quantum Brownian probe strongly coupled to it. We model this scenario by resorting to the canonical Caldeira-Leggett Hamiltonian and find analytically the exact stationary state of the probe for arbitrary coupling strength. In general, the probe does not reach thermal equilibrium with the sample, due to their nonperturbative interaction. We argue that this is advantageous for low-temperature thermometry, as we show in our model that (i) the thermometric precision at low T can be significantly enhanced by strengthening the probe-sampling coupling, (ii) the variance of a suitable quadrature of our Brownian thermometer can yield temperature estimates with nearly minimal statistical uncertainty, and (iii) the spectral density of the probe-sample coupling may be engineered to further improve thermometric performance. These observations may find applications in practical nanoscale thermometry at low temperatures—a regime which is particularly relevant to quantum technologies. American Physical Society 2017-12-04 Article PeerReviewed Correa, Luis A., Perarnau-Llobet, Martí, Hovhannisyan, Karen V., Mehboudi, Mohammad, Hernández-Santana, Senaida and Sanpera, Anna (2017) Enhancement of low-temperature thermometry by strong coupling. Physical Review A, 96 (6). 062103/1-062103/12. ISSN 1094-1622 https://journals.aps.org/pra/abstract/10.1103/PhysRevA.96.062103 doi:10.1103/PhysRevA.96.062103 doi:10.1103/PhysRevA.96.062103 |
| spellingShingle | Correa, Luis A. Perarnau-Llobet, Martí Hovhannisyan, Karen V. Mehboudi, Mohammad Hernández-Santana, Senaida Sanpera, Anna Enhancement of low-temperature thermometry by strong coupling |
| title | Enhancement of low-temperature thermometry by strong coupling |
| title_full | Enhancement of low-temperature thermometry by strong coupling |
| title_fullStr | Enhancement of low-temperature thermometry by strong coupling |
| title_full_unstemmed | Enhancement of low-temperature thermometry by strong coupling |
| title_short | Enhancement of low-temperature thermometry by strong coupling |
| title_sort | enhancement of low-temperature thermometry by strong coupling |
| url | https://eprints.nottingham.ac.uk/48572/ https://eprints.nottingham.ac.uk/48572/ https://eprints.nottingham.ac.uk/48572/ |