Quantum amplification and purification of noisy coherent states
Quantum-limited amplifiers increase the amplitude of quantum signals at the price of introducing additional noise. Quantum purification protocols operate in the reverse way, by reducing the noise while attenuating the signal. Here we investigate a scenario that interpolates between these two extreme...
| প্রধান লেখক: | , |
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| বিন্যাস: | Journal article |
| প্রকাশিত: |
American Physical Society
2017
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| _version_ | 1826274073192169472 |
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| author | Zhao, X Chiribella, G |
| author_facet | Zhao, X Chiribella, G |
| author_sort | Zhao, X |
| collection | OXFORD |
| description | Quantum-limited amplifiers increase the amplitude of quantum signals at the price of introducing additional noise. Quantum purification protocols operate in the reverse way, by reducing the noise while attenuating the signal. Here we investigate a scenario that interpolates between these two extremes. We search for the optimal physical process that generates M approximate copies of a pure and amplified coherent state, starting from N copies of a noisy coherent state with Gaussian modulation. We prove that the optimal deterministic processes are always Gaussian, whereas non-Gaussianity powers up probabilistic advantages in suitable parameter regimes. The optimal processes are experimentally realizable with current technology, both in the deterministic and in the probabilistic scenario. In view of this fact, we provide benchmarks that can be used to certify the experimental demonstration of the quantum-enhanced amplification and purification of coherent states. |
| first_indexed | 2024-03-06T22:37:54Z |
| format | Journal article |
| id | oxford-uuid:5a8cd1f5-22b9-45b2-a262-e281fe70afd8 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T22:37:54Z |
| publishDate | 2017 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | oxford-uuid:5a8cd1f5-22b9-45b2-a262-e281fe70afd82022-03-26T17:16:25ZQuantum amplification and purification of noisy coherent statesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5a8cd1f5-22b9-45b2-a262-e281fe70afd8Symplectic Elements at OxfordAmerican Physical Society2017Zhao, XChiribella, GQuantum-limited amplifiers increase the amplitude of quantum signals at the price of introducing additional noise. Quantum purification protocols operate in the reverse way, by reducing the noise while attenuating the signal. Here we investigate a scenario that interpolates between these two extremes. We search for the optimal physical process that generates M approximate copies of a pure and amplified coherent state, starting from N copies of a noisy coherent state with Gaussian modulation. We prove that the optimal deterministic processes are always Gaussian, whereas non-Gaussianity powers up probabilistic advantages in suitable parameter regimes. The optimal processes are experimentally realizable with current technology, both in the deterministic and in the probabilistic scenario. In view of this fact, we provide benchmarks that can be used to certify the experimental demonstration of the quantum-enhanced amplification and purification of coherent states. |
| spellingShingle | Zhao, X Chiribella, G Quantum amplification and purification of noisy coherent states |
| title | Quantum amplification and purification of noisy coherent states |
| title_full | Quantum amplification and purification of noisy coherent states |
| title_fullStr | Quantum amplification and purification of noisy coherent states |
| title_full_unstemmed | Quantum amplification and purification of noisy coherent states |
| title_short | Quantum amplification and purification of noisy coherent states |
| title_sort | quantum amplification and purification of noisy coherent states |
| work_keys_str_mv | AT zhaox quantumamplificationandpurificationofnoisycoherentstates AT chiribellag quantumamplificationandpurificationofnoisycoherentstates |