Taming the snake instabilities in a polariton superfluid

TL;DR

This paper demonstrates the creation and control of dark solitons in a polariton superfluid, studying their snake instabilities and vortex street formations, and proposes an optical maze-solving application based on these phenomena.

Contribution

It provides the first detailed characterization of snake instabilities in polariton superfluids and introduces a novel all-optical maze solving method utilizing vortex street dynamics.

Findings

Vortex street period scales with the quantum fluid healing length.

Controlled soliton patterns enable optical maze solving.

Snake instabilities lead to vortex street formations in polariton superfluids.

Abstract

The dark solitons observed in a large variety of nonlinear media are unstable against the modulational (snake) instabilities and can break in vortex streets. This behavior has been investigated in nonlinear optical crystals and ultracold atomic gases. However, a deep characterization of this phenomenon is still missing. In a resonantly pumped 2D polariton superfluid, we use an all-optical imprinting technique together with the bistability of the polariton system to create dark solitons in confined channels. Due to the snake instabilities, the solitons are unstable and break in arrays of vortex streets whose dynamical evolution is frozen by the pump-induced confining potential, allowing their direct observation in our system. A deep quantitative study shows that the vortex street period is proportional to the quantum fluid healing length, in agreement with the theoretical predictions. Finally, the full control achieved on the soliton patterns is exploited to give a proof of principle of an efficient, ultra-fast, analog, all-optical maze solving machine in this photonic platform.