Temporal Bell inequalities in a many-body system
| Autor: | Tononi, A., Lewenstein, M. |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Proving the completeness of quantum mechanics has been a fundamental task since its foundation. After the formulation of the Bell inequalities, violated by quantum physics, it is nowadays believed that the theory is complete and non-local. While more general Bell-like inequalities, such as the one of Clauser and Horne, envisage a situation in which two parties choose at random two measurements to perform at causally-disconnected space-times, one could formulate temporal inequalities in which the two parties measure at different times. However, for causally-connected parties, these extensions are compatible with local hidden-variable theories, so that no quantum nature appears in such temporal correlations. Here we show that a temporal Clauser-Horne inequality for two spins is violated for nonzero time interval between the measurements if the two measured parties are connected by a spin chain. The chain constitutes a medium for the spreading of quantum information, which prevents the immediate signaling and thus the deterministic time evolution after the first measurement. Our result suggests that, as expected in a many-body setup, the Lieb-Robinson bound substitutes the speed of light as the fundamental limit for the spreading of information. Comment: 6 pages, 1 figure; comments welcome |
| Databáze: | arXiv |
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