Injection of orbital angular momentum and storage of quantized vortices in polariton superfluids

TL;DR

This paper demonstrates a novel multi-pump method to inject and control angular momentum in polariton superfluids, enabling the creation and manipulation of quantized vortices through experimental and theoretical approaches.

Contribution

It introduces an innovative multi-pump laser configuration for controllably injecting angular momentum into polariton superfluids, facilitating vortex creation and manipulation.

Findings

Vortices with the same sign can be generated and controlled.

Interference patterns disappear in the superfluid regime due to strong interactions.

The number of vortices correlates with the injected angular momentum.

Abstract

We report the experimental investigation and theoretical modeling of a rotating polariton superfluid relying on an innovative method for the injection of angular momentum. This novel, multi-pump injection method uses four coherent lasers arranged in a square, resonantly creating four polariton populations propagating inwards. The control available over the direction of propagation of the superflows allows injecting a controllable non-quantized amount of optical angular momentum. When the density at the center is low enough to neglect polariton-polariton interactions, optical singularities, associated to an interference pattern, are visible in the phase. In the superfluid regime resulting from the strong nonlinear polariton-polariton interaction, the interference pattern disappears and only vortices with the same sign are persisting in the system. Remarkably the number of vortices inside the superfluid region can be controlled by controlling the angular momentum injected by the pumps.