Emergent light crystal from frustration and pump engineering

TL;DR

This paper shows how pump engineering can induce frustration and quasi-long-range order in a low-dimensional photonic lattice, revealing new ways to create strongly-correlated phases in quantum optical systems.

Contribution

It introduces a method to generate frustration-induced order in a photonic lattice via pump design, using a Bose-Hubbard model on a Lieb chain with a flat band.

Findings

Incoherent pumping induces a photonic density-wave with algebraic correlations.

The density-wave has twice the period of the lattice unit cell.

The work suggests new avenues for strongly-correlated phases in quantum optics.

Abstract

We demonstrate how pump engineering drives the emergence of frustration-induced quasi-long-range order in a low-dimensional photonic cavity array. We consider a Lieb chain of nonlinear cavities as described by the Bose-Hubbard model and featuring a photonic flat band in the single-particle spectrum. Incoherent pumping of the Lieb lattice leads to a photonic density-wave which manifests an algebraic decay of correlations with twice the period of the lattice unit cell. This work opens up new directions for the emergence of strongly-correlated phases in quantum optical frustrated systems through pump design.