1998/10/23 by Apoorva Patel, Patel, Apoorva
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #hep-th #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/9810071
8 pages, two column revtex, arguments elaborated and strengthened, submitted to Physical Review A
openalex publication_date 1998/10/23 · arxiv created 1998/12/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Feynman's path integrals provide a hidden variable description of quantum mechanics (and quantum field theories). The time evolution kernel is unitary in Minkowski time, but generically it becomes real and non-negative in Euclidean time. It follows that the entangled state correlations, that violate Bell's inequalities in Minkowski time, obey the inequalities in Euclidean time. This observation emphasises the link between violation of Bell's inequalities in quantum mechanics and unitarity of the theory. Search for an evolution kernel that cannot be conveniently made non-negative leads to effective interactions that violate time reversal invariance. Interactions giving rise to geometric phases in the effective description of the theory, such as the anomalous Wess-Zumino interactions, have this feature. I infer that they must be present in any set-up that produces entangled states violating Bell's inequalities. Such interactions would be a crucial ingredient in a quantum computer.