Device-independent self-testing of unsharp measurements
Semi-device-independent certification of an unsharp instrument has recently been demonstrated (2019 New J. Phys. 21 083034) based on the sequential sharing of quantum advantages in a prepare-measure communication game by assuming the system to be qubit. In this work, we provide device-independent (D...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/acb4b5 |
| _version_ | 1797748764183625728 |
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| author | Prabuddha Roy A K Pan |
| author_facet | Prabuddha Roy A K Pan |
| author_sort | Prabuddha Roy |
| collection | DOAJ |
| description | Semi-device-independent certification of an unsharp instrument has recently been demonstrated (2019 New J. Phys. 21 083034) based on the sequential sharing of quantum advantages in a prepare-measure communication game by assuming the system to be qubit. In this work, we provide device-independent (DI) self-testing of the unsharp instrument through the quantum violation of two Bell inequalities where the devices are uncharacterized and the dimension of the system remains unspecified. We introduce an elegant sum-of-squares approach to derive the dimension-independent optimal quantum violation of Bell inequalities which plays a crucial role. Note that the standard Bell test cannot self-test the post-measurement states and consequently cannot self-test unsharp instrument. The sequential Bell test possess the potential to self-test an unsharp instrument. We demonstrate that there exists a trade-off between the maximum sequential quantum violations of the Clauser–Horne–Shimony–Holt inequality, and they form an optimal pair that enables the DI self-testing of the entangled state, the observables, and the unsharpness parameter. Further, we extend our study to the case of elegant Bell inequality and we argue that it has two classical bounds—the local bound and the non-trivial preparation non-contextual bound, lower than the local bound. Based on the sharing of preparation contextuality by three independent sequential observers, we demonstrate the DI self-testing of two unsharpness parameters. Since an actual experimental scenario involves losses and imperfection, we demonstrate robustness of our certification to noise. |
| first_indexed | 2024-03-12T16:09:31Z |
| format | Article |
| id | doaj.art-6fbb265ea95c41409e4fb0a4da852b0c |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:09:31Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-6fbb265ea95c41409e4fb0a4da852b0c2023-08-09T14:11:18ZengIOP PublishingNew Journal of Physics1367-26302023-01-0125101304010.1088/1367-2630/acb4b5Device-independent self-testing of unsharp measurementsPrabuddha Roy0A K Pan1https://orcid.org/0000-0001-8874-9363National Institute of Technology Patna , Ashok Rajpath, Patna, Bihar 800005, IndiaNational Institute of Technology Patna , Ashok Rajpath, Patna, Bihar 800005, India; Department of Physics, Indian Institute of Technology Hyderabad , Telengana 502284, IndiaSemi-device-independent certification of an unsharp instrument has recently been demonstrated (2019 New J. Phys. 21 083034) based on the sequential sharing of quantum advantages in a prepare-measure communication game by assuming the system to be qubit. In this work, we provide device-independent (DI) self-testing of the unsharp instrument through the quantum violation of two Bell inequalities where the devices are uncharacterized and the dimension of the system remains unspecified. We introduce an elegant sum-of-squares approach to derive the dimension-independent optimal quantum violation of Bell inequalities which plays a crucial role. Note that the standard Bell test cannot self-test the post-measurement states and consequently cannot self-test unsharp instrument. The sequential Bell test possess the potential to self-test an unsharp instrument. We demonstrate that there exists a trade-off between the maximum sequential quantum violations of the Clauser–Horne–Shimony–Holt inequality, and they form an optimal pair that enables the DI self-testing of the entangled state, the observables, and the unsharpness parameter. Further, we extend our study to the case of elegant Bell inequality and we argue that it has two classical bounds—the local bound and the non-trivial preparation non-contextual bound, lower than the local bound. Based on the sharing of preparation contextuality by three independent sequential observers, we demonstrate the DI self-testing of two unsharpness parameters. Since an actual experimental scenario involves losses and imperfection, we demonstrate robustness of our certification to noise.https://doi.org/10.1088/1367-2630/acb4b5sharing of nonlocalitydevice-independent self-testingunsharp measurement |
| spellingShingle | Prabuddha Roy A K Pan Device-independent self-testing of unsharp measurements New Journal of Physics sharing of nonlocality device-independent self-testing unsharp measurement |
| title | Device-independent self-testing of unsharp measurements |
| title_full | Device-independent self-testing of unsharp measurements |
| title_fullStr | Device-independent self-testing of unsharp measurements |
| title_full_unstemmed | Device-independent self-testing of unsharp measurements |
| title_short | Device-independent self-testing of unsharp measurements |
| title_sort | device independent self testing of unsharp measurements |
| topic | sharing of nonlocality device-independent self-testing unsharp measurement |
| url | https://doi.org/10.1088/1367-2630/acb4b5 |
| work_keys_str_mv | AT prabuddharoy deviceindependentselftestingofunsharpmeasurements AT akpan deviceindependentselftestingofunsharpmeasurements |