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Bell-state measurement exceeding 50% success probability with linear optics

Quantum Physics 2023-09-06 v1

Abstract

Bell-state projections serve as a fundamental basis for most quantum communication and computing protocols today. However, with current Bell-state measurement schemes based on linear optics, only two of four Bell states can be identified, which means that the maximum success probability of this vital step cannot exceed 50%50\%. Here, we experimentally demonstrate a scheme that amends the original measurement with additional modes in the form of ancillary photons, which leads to a more complex measurement pattern, and ultimately a higher success probability of 62.5%62.5\%. Experimentally, we achieve a success probability of (57.9±1.4)%(57.9 \pm 1.4)\%, a significant improvement over the conventional scheme. With the possibility of extending the protocol to a larger number of ancillary photons, our work paves the way towards more efficient realisations of quantum technologies based on Bell-state measurements.

Keywords

Cite

@article{arxiv.2208.02271,
  title  = {Bell-state measurement exceeding 50% success probability with linear optics},
  author = {Matthias J. Bayerbach and Simone E. D'Aurelio and Peter van Loock and Stefanie Barz},
  journal= {arXiv preprint arXiv:2208.02271},
  year   = {2023}
}
R2 v1 2026-06-25T01:27:31.295Z