English

Measuring outcome correlation for spin-s Bell cat-state and geometric phase induced spin parity effect

Quantum Physics 2022-01-04 v2

Abstract

In terms of quantum probability statistics the Bell inequality (BI) and its violation are extended to spin-ss entangled Schr\"{o}dinger cat-state (called the Bell cat-state) with both parallel and antiparallel spin-polarizations. The BI is never ever violated for the measuring outcome probabilities evaluated over entire two-spin Hilbert space except the spin-1/21/2 entangled states. A universal Bell-type inequality (UBI) denoted by pslc0p_{s}^{lc}\leq0 is formulated with the local realistic model under the condition that the measuring outcomes are restricted in the subspace of spin coherent states. A spin parity effect is observed that the UBI can be violated only by the Bell cat-states of half-integer but not the integer spins. The violation of UBI is seen to be a direct result of non-trivial Berry phase between the spin coherent states of south- and north-pole gauges for half-integer spin, while the geometric phase is trivial for the integer spins. A maximum violation bound of UBI is found as psmaxp_{s}^{\max}=1, which is valid for arbitrary half-integer spin-ss states.

Keywords

Cite

@article{arxiv.1903.12345,
  title  = {Measuring outcome correlation for spin-s Bell cat-state and geometric phase induced spin parity effect},
  author = {Yan Gu and Haifeng Zhang and Zhigang Song and L. -F. Wei and J. -Q. Liang},
  journal= {arXiv preprint arXiv:1903.12345},
  year   = {2022}
}

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11 pages