We present a method to map the evolution of photonic random walks that is compatible with nonclassical input light. Our approach leverages a newly developed flexible waveguide platform to tune the jumping rate between spatial modes, allowing the observation of a range of evolution times in a chip of fixed length. In a proof-of-principle demonstration we reconstruct the evolution of photons through a uniform array of coupled waveguides by monitoring the end-face alone. This approach enables direct observation of mode occupancy at arbitrary resolution, extending the utility of photonic random walks for quantum simulations and related applications.
@article{arxiv.1802.09712,
title = {Mapping a quantum walk by tuning the coupling coefficient},
author = {Kian Fong Ng and Manuel J. L. F. Rodrigues and José Viana-Gomes and Alexander Ling and James A. Grieve},
journal= {arXiv preprint arXiv:1802.09712},
year = {2019}
}