Quantum Walks of Correlated Photon Pairs in Two-Dimensional Waveguide Arrays

Kostas Poulios, Robert Keil, Daniel Fry, Jasmin D. A. Meinecke, Jonathan C. F. Matthews, Alberto Politi, Mirko Lobino, Markus Graefe, Matthias Heinrich, Stefan Nolte, Alexander Szameit, Jeremy L. O'Brien

Research output: Contribution to journalArticle (Academic Journal)peer-review

121 Citations (Scopus)


We demonstrate quantum walks of correlated photons in a two-dimensional network of directly laser written waveguides coupled in a "swiss cross" arrangement. The correlated detection events show high-visibility quantum interference and unique composite behavior: strong correlation and independence of the quantum walkers, between and within the planes of the cross. Violations of a classically defined inequality, for photons injected in the same plane and in orthogonal planes, reveal nonclassical behavior in a nonplanar structure.

Original languageEnglish
Article number143604
Number of pages5
JournalPhysical Review Letters
Issue number143604
Publication statusPublished - 10 Apr 2014

Structured keywords

  • QETLabs


  • Photons
  • quantum walks
  • waveguides
  • photonics
  • Quantum optics


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