Weak values and the past of a quantum particle
We investigate four key issues with using a nonzero weak value of the spatial projection operator to infer the past path of an individual quantum particle. First, we note that weak measurements disturb a system, so any approach relying on such a perturbation to determine the location of a quantum pa...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2023-04-01
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| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.5.023048 |
| _version_ | 1797210531778527232 |
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| author | Jonte R. Hance John Rarity James Ladyman |
| author_facet | Jonte R. Hance John Rarity James Ladyman |
| author_sort | Jonte R. Hance |
| collection | DOAJ |
| description | We investigate four key issues with using a nonzero weak value of the spatial projection operator to infer the past path of an individual quantum particle. First, we note that weak measurements disturb a system, so any approach relying on such a perturbation to determine the location of a quantum particle describes the state of a disturbed system, not that of a hypothetical undisturbed system. Second, even assuming no disturbance, there is no reason to associate the nonzero weak value of an operator containing the spatial projection operator with the classical idea of “particle presence.” Third, weak values are only measurable over ensembles, and so to infer properties of individual particles from values of them is problematic. Finally, weak value approaches to the path of a particle do not provide information beyond standard quantum mechanics (and the classical modes supporting the experiment). We know of no experiment with testable consequences that demonstrates a connection between particle presence and weak values. |
| first_indexed | 2024-04-24T10:12:05Z |
| format | Article |
| id | doaj.art-b5f44e315a274f218eab221ee7288e00 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:12:05Z |
| publishDate | 2023-04-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-b5f44e315a274f218eab221ee7288e002024-04-12T17:30:22ZengAmerican Physical SocietyPhysical Review Research2643-15642023-04-015202304810.1103/PhysRevResearch.5.023048Weak values and the past of a quantum particleJonte R. HanceJohn RarityJames LadymanWe investigate four key issues with using a nonzero weak value of the spatial projection operator to infer the past path of an individual quantum particle. First, we note that weak measurements disturb a system, so any approach relying on such a perturbation to determine the location of a quantum particle describes the state of a disturbed system, not that of a hypothetical undisturbed system. Second, even assuming no disturbance, there is no reason to associate the nonzero weak value of an operator containing the spatial projection operator with the classical idea of “particle presence.” Third, weak values are only measurable over ensembles, and so to infer properties of individual particles from values of them is problematic. Finally, weak value approaches to the path of a particle do not provide information beyond standard quantum mechanics (and the classical modes supporting the experiment). We know of no experiment with testable consequences that demonstrates a connection between particle presence and weak values.http://doi.org/10.1103/PhysRevResearch.5.023048 |
| spellingShingle | Jonte R. Hance John Rarity James Ladyman Weak values and the past of a quantum particle Physical Review Research |
| title | Weak values and the past of a quantum particle |
| title_full | Weak values and the past of a quantum particle |
| title_fullStr | Weak values and the past of a quantum particle |
| title_full_unstemmed | Weak values and the past of a quantum particle |
| title_short | Weak values and the past of a quantum particle |
| title_sort | weak values and the past of a quantum particle |
| url | http://doi.org/10.1103/PhysRevResearch.5.023048 |
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