Flat-band compactons in a two-dimensional driven-dissipative Lieb lattice

TL;DR

This paper demonstrates the experimental creation of nonlinear compact localized states, called compactons, in a driven-dissipative Lieb lattice with exciton polaritons, revealing new insights into flat-band physics and potential quantum applications.

Contribution

It reports the first experimental observation of nonlinear compactons in a driven-dissipative flat-band system, highlighting the role of interactions and nonlinearity in flat-band localization.

Findings

Observation of compactons embedded in continuum bands

Self-localization occurs above a threshold power

Experimental results align with numerical simulations

Abstract

We experimentally study the effect of inter-particle interactions on the flat-band states of a two-dimensional Lieb lattice with drive and dissipation. Exploiting the giant nonlinear interactions of exciton polaritons we observe compactly localised solitons (compactons) embedded within the continuum of propagating state bands -- a form of nonlinear bound state in the continuum (BIC). The driven-dissipative nature of the system leads to a sudden self-localisation into the compacton state above a threshold power. The experimental results agree well with numerical simulations. These results have implications for the physics of interacting quantum particles in flat-band systems and for generation of quantum-correlated light and spatially multiplexed coherent information transport.