Poulios, Konstantinos, Keil, Robert, Fry, Daniel, D. A. Meinecke, Jasmin, C. F. Matthews, Jonathan, Politi, Alberto, Lobino, Mirko, Gräfe, Markus, Heinrich, Matthias, Nolte, Stefan, Szameit, Alexander, L. O'Brien, Jeremy, "Quantum Walks of Correlated Photon Pairs in Two-Dimensional Waveguide Arrays", Physical Review Letters, 2014