Mapping a quantum walk by tuning the coupling coefficient

TL;DR

This paper introduces a method to map photonic quantum walks by tuning coupling coefficients in a waveguide platform, enabling detailed observation of photon evolution for quantum simulation.

Contribution

It presents a novel approach to control and observe photonic quantum walks using a flexible waveguide platform with tunable coupling, allowing for detailed evolution mapping.

Findings

Successful reconstruction of photon evolution in waveguide arrays

Demonstration of tuning coupling to observe different evolution times

Extension of photonic quantum walks utility for quantum simulations

Abstract

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.