Quantum and classical correlations in waveguide lattices

TL;DR

This paper investigates quantum and classical correlations in waveguide lattices, developing a theory for photon pair propagation, observing classical interference patterns, and exploring the potential for quantum state manipulation.

Contribution

It introduces a new theoretical framework for photon pair propagation in waveguide lattices and experimentally demonstrates classical correlations, highlighting the system's potential for quantum control.

Findings

Quantum interferences are unique to lattice systems.

Classical intensity correlations mimic quantum effects.

Waveguide lattices can manipulate quantum states effectively.

Abstract

We study quantum and classical Hanbury Brown-Twiss correlations in waveguide lattices. We develop a theory for the propagation of photon pairs in the lattice, predicting the emergence of nontrivial quantum interferences unique to lattice systems. Experimentally, we observe the classical counterpart of these interferences using intensity correlation measurements. We discuss the correspondence between the classical and quantum correlations, and consider path-entangled input states which do not have a classical analogue. Our results demonstrate that waveguide lattices can be used as a robust and highly controllable tool for manipulating quantum states, and offer new ways of studying the quantum properties of light.