Experimental violation of the Leggett–Garg inequality in a three-level system
The Leggett–Garg (LG) test of macroscopic realism involves a series of dichotomic non-invasive measurements that are used to calculate a function which has a fixed upper bound for a macrorealistic system and a larger upper bound for a quantum system. The quantum upper bound depends on both the detai...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/aa5c51 |
| _version_ | 1797750855840038912 |
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| author | Hemant Katiyar Aharon Brodutch Dawei Lu Raymond Laflamme |
| author_facet | Hemant Katiyar Aharon Brodutch Dawei Lu Raymond Laflamme |
| author_sort | Hemant Katiyar |
| collection | DOAJ |
| description | The Leggett–Garg (LG) test of macroscopic realism involves a series of dichotomic non-invasive measurements that are used to calculate a function which has a fixed upper bound for a macrorealistic system and a larger upper bound for a quantum system. The quantum upper bound depends on both the details of the measurement and the dimension of the system. Here we present an LG experiment on a three-level quantum system, which produces a larger theoretical quantum upper bound than that of a two-level quantum system. The experiment is carried out in nuclear magnetic resonance and consists of the LG test as well as a test of the ideal assumptions associated with the experiment, such as measurement non-invasiveness. The non-invasive measurements are performed via the modified ideal negative result measurement scheme on a three-level system. Once these assumptions are tested, the violation becomes small, despite the fact that the LG value itself is large. Our results showcase the advantages of using the modified measurement scheme that can reach higher LG values, since these leave a larger margin for violating the inequality in the face of experimental imperfections. |
| first_indexed | 2024-03-12T16:39:53Z |
| format | Article |
| id | doaj.art-cbc509162bdb4d719497a6de45e30cc9 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:39:53Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-cbc509162bdb4d719497a6de45e30cc92023-08-08T14:36:03ZengIOP PublishingNew Journal of Physics1367-26302017-01-0119202303310.1088/1367-2630/aa5c51Experimental violation of the Leggett–Garg inequality in a three-level systemHemant Katiyar0Aharon Brodutch1https://orcid.org/0000-0001-5536-1485Dawei Lu2Raymond Laflamme3Institute for Quantum Computing, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada; Department of Physics and Astronomy, University of Waterloo , Waterloo, Ontario N2L 3G1, CanadaInstitute for Quantum Computing, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada; Department of Physics and Astronomy, University of Waterloo , Waterloo, Ontario N2L 3G1, CanadaInstitute for Quantum Computing, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada; Department of Physics and Astronomy, University of Waterloo , Waterloo, Ontario N2L 3G1, CanadaInstitute for Quantum Computing, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada; Department of Physics and Astronomy, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada; Perimeter Institute for Theoretical Physics, Waterloo N2L 2Y5, Ontario, Canada; Canadian Institute for Advanced Research, Toronto, Ontario, CanadaThe Leggett–Garg (LG) test of macroscopic realism involves a series of dichotomic non-invasive measurements that are used to calculate a function which has a fixed upper bound for a macrorealistic system and a larger upper bound for a quantum system. The quantum upper bound depends on both the details of the measurement and the dimension of the system. Here we present an LG experiment on a three-level quantum system, which produces a larger theoretical quantum upper bound than that of a two-level quantum system. The experiment is carried out in nuclear magnetic resonance and consists of the LG test as well as a test of the ideal assumptions associated with the experiment, such as measurement non-invasiveness. The non-invasive measurements are performed via the modified ideal negative result measurement scheme on a three-level system. Once these assumptions are tested, the violation becomes small, despite the fact that the LG value itself is large. Our results showcase the advantages of using the modified measurement scheme that can reach higher LG values, since these leave a larger margin for violating the inequality in the face of experimental imperfections.https://doi.org/10.1088/1367-2630/aa5c51Leggett–Garg inequalityfoundation of quantum mechanicsnuclear magnetic resonance |
| spellingShingle | Hemant Katiyar Aharon Brodutch Dawei Lu Raymond Laflamme Experimental violation of the Leggett–Garg inequality in a three-level system New Journal of Physics Leggett–Garg inequality foundation of quantum mechanics nuclear magnetic resonance |
| title | Experimental violation of the Leggett–Garg inequality in a three-level system |
| title_full | Experimental violation of the Leggett–Garg inequality in a three-level system |
| title_fullStr | Experimental violation of the Leggett–Garg inequality in a three-level system |
| title_full_unstemmed | Experimental violation of the Leggett–Garg inequality in a three-level system |
| title_short | Experimental violation of the Leggett–Garg inequality in a three-level system |
| title_sort | experimental violation of the leggett garg inequality in a three level system |
| topic | Leggett–Garg inequality foundation of quantum mechanics nuclear magnetic resonance |
| url | https://doi.org/10.1088/1367-2630/aa5c51 |
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