Subdiffusive dynamics in photonic random walks probed with classical light

TL;DR

This paper demonstrates that intense classical light in photonic lattices can exhibit subdiffusive behavior, distinct from classical and quantum walks, by disentangling quantum and ensemble effects using dephasing dynamics.

Contribution

It introduces a method to observe subdiffusive photon dynamics in classical light, revealing behaviors different from traditional quantum or classical walks.

Findings

Classical light can exhibit subdiffusive dynamics in photonic lattices.

Dephasing dynamics enable disentangling quantum and ensemble effects.

Proposed photonic random walks in synthetic lattices demonstrate these phenomena.

Abstract

The random walk of photons in a tight-binding lattice is known to exhibit diffusive motion similar to classical random walks under decoherence, clearly illustrating the quantum-to-classical transition. In this study, we reveal that the random walk of intense classical light under dephasing dynamics can disentangle quantum and ensemble averaging, making it possible to observe a subdiffusive walker dynamics, i.e. a behavior very distinct from both a classical and a quantum walker. These findings are demonstrated through proposing photonic random walks in synthetic temporal lattices, based on pulse dynamics in coupled fiber loops.