Entanglement indicators for quantum optical fields: three-mode multiport beamsplitters EPR interference experiments
Ryu Jeonghee , Marcin Marciniak , Marcin Wieśniak , Marek Żukowski
AbstractWe generalize a new approach to entanglement conditions for light of undefined photons numbers given in Żukowski et al (2017 Phys. Rev. A 95 042113) for polarization correlations to a broader family of interferometric phenomena. Integrated optics allows one to perform experiments based upon multiport beamsplitters. To observe entanglement effects one can use multi-mode parametric down-conversion emissions. When the structure of the Hamiltonian governing the emissions has (infinitely) many equivalent Schmidt decompositions into modes (beams), one can have perfect EPR-like correlations of numbers of photons emitted into 'conjugate modes' which can be monitored at spatially separated detection stations. We provide entanglement conditions for experiments involving three modes on each side, and three-input-three-output multiport beamsplitters, and show their violations by bright squeezed vacuum states. We show that a condition expressed in terms of averages of observed rates is a much better entanglement indicator than a related one for the usual intensity variables. Thus, the rates seem to emerge as a powerful concept in quantum optics, especially for fields of undefined intensities.
|Journal series||Journal of Optics, ISSN 2040-8978, [2040-8986], (A 35 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Entanglement indicator, EPR interference experiments, bright squeezed vacuum, Stokes parameters, integrated optics|
|Score||= 35.0, 17-11-2019, ArticleFromJournal|
|Publication indicators||: 2018 = 1.033; : 2018 = 2.753 (2) - 2018=2.246 (5)|
|Citation count*||3 (2020-01-17)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.