A topological attractor of vortices as a clock generator based on polariton superfluids

TL;DR

This paper demonstrates a topologically protected, persistent oscillatory vortex dynamics in a polariton superfluid, functioning as a stable, tunable clock generator with bistability and controllable frequency states.

Contribution

It introduces a novel topological attractor in polariton superfluids that enables stable, tunable oscillations for potential applications in photonic clock devices.

Findings

Persistent oscillations at GHz frequencies driven by vortex dynamics.

The attractor's stability against perturbations.

Frequency tunability and bistability via pump control.

Abstract

We reveal a topologically protected persistent oscillatory dynamics of a polariton superfluid, which is driven non-resonantly by a super-Gaussian laser beam in a planar semiconductor microcavity subjected to an external C-shape potential. We find persistent oscillations, characterized by a topological attractor, that are based on the dynamical behavior of small Josephson vortices rotating around the outside edge of the central vortex. The attractor is being formed due to the inverse energy cascade accompanied by the growth of the incompressible kinetic energy. The attractor displays a remarkable stability towards perturbations and it may be tuned by the pump laser intensity to two distinct frequency ranges: 20.16$\pm$0.14 GHz and 48.4$\pm$1.2 GHz. This attractor is bistable due to the chirality of the vortex. The switching between two stable states is achieved by altering the pump power or by adding an extra incoherent Gaussian pump beam.