Noninvasiveness and time symmetry of weak measurements
Measurements in classical and quantum physics are described in fundamentally different ways. Nevertheless, one can formally define similar measurement procedures with respect to the disturbance they cause. Obviously, strong measurements, both classical and quantum, are invasive—they disturb the meas...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2013-01-01
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| Series: | New Journal of Physics |
| Online Access: | https://doi.org/10.1088/1367-2630/15/2/023043 |
| _version_ | 1797751710936989696 |
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| author | Adam Bednorz Kurt Franke Wolfgang Belzig |
| author_facet | Adam Bednorz Kurt Franke Wolfgang Belzig |
| author_sort | Adam Bednorz |
| collection | DOAJ |
| description | Measurements in classical and quantum physics are described in fundamentally different ways. Nevertheless, one can formally define similar measurement procedures with respect to the disturbance they cause. Obviously, strong measurements, both classical and quantum, are invasive—they disturb the measured system. We show that it is possible to define general weak measurements, which are noninvasive: the disturbance becomes negligible as the measurement strength goes to zero. Classical intuition suggests that noninvasive measurements should be time symmetric (if the system dynamics is reversible) and we confirm that correlations are time-reversal symmetric in the classical case. However, quantum weak measurements—defined analogously to their classical counterparts—can be noninvasive but not time symmetric. We present a simple example of measurements on a two-level system which violates time symmetry and propose an experiment with quantum dots to measure the time-symmetry violation in a third-order current correlation function. |
| first_indexed | 2024-03-12T16:52:33Z |
| format | Article |
| id | doaj.art-5476d1b337d844e3ae289bd9f5ea3dee |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:52:33Z |
| publishDate | 2013-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-5476d1b337d844e3ae289bd9f5ea3dee2023-08-08T11:05:33ZengIOP PublishingNew Journal of Physics1367-26302013-01-0115202304310.1088/1367-2630/15/2/023043Noninvasiveness and time symmetry of weak measurementsAdam Bednorz0Kurt Franke1Wolfgang Belzig2Faculty of Physics, University of Warsaw , Hoża 69, PL-00681 Warsaw, PolandFachbereich Physik, Universität Konstanz , D-78457 Konstanz, GermanyFachbereich Physik, Universität Konstanz , D-78457 Konstanz, GermanyMeasurements in classical and quantum physics are described in fundamentally different ways. Nevertheless, one can formally define similar measurement procedures with respect to the disturbance they cause. Obviously, strong measurements, both classical and quantum, are invasive—they disturb the measured system. We show that it is possible to define general weak measurements, which are noninvasive: the disturbance becomes negligible as the measurement strength goes to zero. Classical intuition suggests that noninvasive measurements should be time symmetric (if the system dynamics is reversible) and we confirm that correlations are time-reversal symmetric in the classical case. However, quantum weak measurements—defined analogously to their classical counterparts—can be noninvasive but not time symmetric. We present a simple example of measurements on a two-level system which violates time symmetry and propose an experiment with quantum dots to measure the time-symmetry violation in a third-order current correlation function.https://doi.org/10.1088/1367-2630/15/2/023043 |
| spellingShingle | Adam Bednorz Kurt Franke Wolfgang Belzig Noninvasiveness and time symmetry of weak measurements New Journal of Physics |
| title | Noninvasiveness and time symmetry of weak measurements |
| title_full | Noninvasiveness and time symmetry of weak measurements |
| title_fullStr | Noninvasiveness and time symmetry of weak measurements |
| title_full_unstemmed | Noninvasiveness and time symmetry of weak measurements |
| title_short | Noninvasiveness and time symmetry of weak measurements |
| title_sort | noninvasiveness and time symmetry of weak measurements |
| url | https://doi.org/10.1088/1367-2630/15/2/023043 |
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