Possibilistic and maximal indefinite causal order in the quantum switch

Autor:	van der Lugt, Tein, Ormrod, Nick
Rok vydání:	2023
Předmět:	Quantum Physics
Druh dokumentu:	Working Paper
Popis:	It was recently found that the indefinite causal order in the quantum switch can be certified device-independently when assuming the impossibility of superluminal influences. Here we strengthen this result in two ways. First, we give a proof of this fact which is possibilistic, rather than probabilistic, i.e. which does not rely on the validity of probability theory at the hidden variable level. Then, returning to the probabilistic setting, we show that the indefinite causal order in the quantum switch is also maximal, in the sense that the observed correlations are incompatible even with the existence of a causal order on only a small fraction of the runs of the experiment. While the original result makes use of quantum theory's violation of a Clauser-Horne-Shimony-Holt inequality, the proofs presented here are based on Greenberger, Horne, and Zeilinger's and Mermin's proofs of nonlocality, respectively. Comment: 7+8 pages, 5 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2311.00557 Zobrazit plný text záznamu View this record from Arxiv