Spatial dissipative solitons in graphene-based active random metamaterials

TL;DR

This paper explores how graphene-based active metamaterials can support self-organized dissipative solitons, revealing the conditions for their formation and stability, with implications for future laser and amplifier technologies.

Contribution

It demonstrates the existence and dynamics of dissipative solitons in disordered graphene metamaterials, highlighting the role of nonlinearities and topological charges.

Findings

Graphene nonlinearity induces sub-critical bifurcation of modes.

Dissipative solitons can form with distinct topological charges.

Soliton vortices are unstable, leading to single-charge structures.

Abstract

We investigate dissipative nonlinear dynamics in graphene-based active metamaterials composed of randomly dispersed graphene nano-flakes embedded within an externally pumped gain medium. We observe that graphene saturable nonlinearity produces a sub-critical bifurcation of nonlinear modes, enabling self-organization of the emitted radiation into several dissipative soliton structures with distinct topological charges. We systematically investigate the existence domains of such nonlinear waves and their spatio-temporal dynamics, finding that soliton vortices are unstable, thus enabling self-organization into single dissipative structures with vanishing topological charge, independently of the shape of the graphene nano-flakes. Our results shed light on self-organization of coherent radiation structures in disordered systems and are relevant for future cavity-free lasers and amplifier designs.