Entanglement witness on a programmable photonic processor

Research output: Contribution to conferencePosterAcademic


Multiphoton quantum interference is a one of the two technology platforms in which a quantum advantage has been demonstrated [1]. In these systems, a large-scale quantum state forms due to repeated effective interactions of photons (through the generalized Hong-Ou-Mandel effect) at the nodes of a photonic processor, resulting in a state that intrinsically possesses quantum complexity.

A key question is how to validate the formation of a large-scale quantum state. One aspect of this is to measure whether the output quantum state is entangled – a necessary but not sufficient criterion for complexity.

In this work, we derive and demonstrate an entanglement witness for large-scale optical quantum interference, and experimentally use this to demonstrate the presence of entanglement in our optical processor [2].

[1] Zhong et al., Science 370, 1460 – 1463 (2020)
[2] Taballione et al., ArXiv 2012.05673 (2021)
Original languageEnglish
Publication statusPublished - 12 Oct 2021
Event44th Annual Meeting NNV AMO Lunteren 2021 - De Werelt, Lunteren, Netherlands
Duration: 12 Oct 202113 Oct 2021
Conference number: 44


Conference44th Annual Meeting NNV AMO Lunteren 2021
Internet address


  • Quantum
  • Entanglement witness
  • Single photon
  • Integrated photonics


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