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

TL;DR

This paper demonstrates the use of an elliptical waveguide array in integrated optics to emulate quantum systems through two-photon quantum walks, highlighting differences based on photon indistinguishability and confirming the feasibility of 3D quantum emulation.

Contribution

It introduces a novel elliptical waveguide array for two-photon quantum walks and validates quantum emulation in 3D integrated photonic structures.

Findings

Distinct differences between indistinguishable and distinguishable two-photon inputs

Successful characterization of the photonic chip via coherent-light tomography

Feasibility of emulating quantum phenomena in 3D waveguide structures

Abstract

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.