Controlled ordering of topological charges in an exciton-polariton chain

TL;DR

This paper demonstrates the controlled creation of vortex chains with specific topological charges in an exciton-polariton array, enabling tunable topological and chiral properties through pump shaping.

Contribution

It introduces a method to switch between different vortex chain orders in a polariton system using tailored incoherent pumping, revealing new topological control mechanisms.

Findings

Successful experimental and theoretical control of vortex chain order.

Realization of ferromagnetic and anti-ferromagnetic vortex arrangements.

Observation of persistent chiral currents in the system.

Abstract

We demonstrate, experimentally and theoretically, controlled loading of an exciton-polariton vortex chain into a 1D array of trapping potentials. Switching between two types of vortex chains, with topological charges of the same or alternating sign, is realised by means of appropriate shaping of an incoherent pump beam that drives the system to the regime of bosonic condensation. In analogy to spin chains, these vortex sequences realise either a "ferromagnetic" or an "anti-ferromagnetic" order, whereby the role of spin is played by the orbital angular momentum. The "ferromagnetic" ordering of vortices is associated with the formation of a persistent chiral current. Our results pave the way for controlled creation of nontrivial distributions of orbital angular momentum and topological order in a periodic exciton-polariton system.