Persistent circular currents of exciton-polaritons in cylindrical pillar microcavities

TL;DR

This paper reports the experimental observation of persistent exciton-polariton currents with topological charges in cylindrical microcavities, revealing spiral interference patterns indicative of eddy currents in polariton condensates.

Contribution

It introduces the first experimental visualization of circular polariton currents with specific topological charges in cylindrical microcavities.

Findings

Observation of polariton eddy currents with topological charges m=+1, -1, -2

Visualization of spiral interference patterns in microcavities

Identification of twin spiral pattern for charge m=-2

Abstract

We have experimentally observed an eddy current of exciton polaritons arising in a cylindrical GaAs/AlGaAs pillar microcavity under the nonresonant optical pumping. The polariton current manifests itself in a Mach-Zehnder interferometry image as a characteristic spiral that occurs due to the interference of the light emitted by an exciton-polariton condensate with a spherical wave artificially shaped from the emission of the same condensate. We have experimentally observed the condensates with the topological charges m = +1, m = -1 and m = -2. The interference pattern corresponding to the m = -2 current represents the twin spiral emerging from the center of the micropillar.