Two-photon quantum walks in an elliptical direct-write waveguide array

Abstract

Integrated optics provides an ideal testbed 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 characterize 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. This work highlights the feasibility of emulation of coherent quantum phenomena in three-dimensional waveguide structures. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.