Polariton lasing in the edge states of an orbital SSH chain

Abstract

Engineering orbital bands in photonic simulators (i.e., bands emerging from the coupling of 1φ0 orbitais) provides an excellent platform to study novel transport, and nonlinear and topological phenomena in solids [1]. For example, they allow studying flat bands in a honeycomb lattice [2], exotic edge states of topologically non-trivial orbital bands, orbital symmetry breaking [3], and orbital superfluidity [4]. Cavity polaritons are well-suited for implementing these simulators, because their photonic part allows coupling p- and higher photonic orbitals in extended lattices [3], while their excitonic part furnishes strong interactions that are required for investigating non-linear effects. In this work, we elaborate and demonstrate an orbital version of the well-known Su-Schrieffer-Heeger model (SSH) using p-bands in a zigzag chain of polariton micropillars (see Fig. (a)-(c)) and show polariton lasing in the topological edge states located at the ends of the chain. The demonstration of polariton lasing in topological edge states opens the way to the study of nonlinear transport in chiral states of topological insulators [5].