Two-photon quantum walks in an elliptical direct-write waveguide array
  Integrated optics provides an ideal test bed for the emulation of quantum systems via continuous-time quantum walks. Here we study the evolution of two-photon states in an elliptic array of waveguides. We characterise the photonic chip via coherent-light tomography and use the results to predict distinct differences between temporally indistinguishable and distinguishable two-photon inputs which we then compare with experimental observations. Our work highlights the feasibility for emulation of coherent quantum phenomena in three-dimensional waveguide structures. 
J. O. Owens, M. A. Broome, D. N. Biggerstaff, M. E. Goggin, A.   Fedrizzi, T. Linjordet, M. Ams, G. D. Marshall, J. Twamley,...
quant-ph physics.optics