Topological Pathways to Two-Dimensional Quantum Turbulence

TL;DR

This study combines experiments and theory to understand how vortices form and decay in two-dimensional quantum turbulence, emphasizing the role of topological constraints in the dynamics of quantum fluids.

Contribution

It introduces a kinetic model based on topological conservation laws that accurately describes vortex dynamics in 2D quantum turbulence.

Findings

Vortex formation and decay involve critical points of the velocity field.

Different mechanisms govern vortex number growth and decay.

Topological constraints are crucial in turbulent evolution.

Abstract

We present a combined experimental and theoretical investigation of the formation and decay kinetics of vortices in two dimensional, compressible quantum turbulence. We follow the temporal evolution of a quantum fluid of exciton polaritons, hybrid light matter quasiparticles, and measure both phase and modulus of the order parameter in the turbulent regime. Fundamental topological conservation laws require that the formation and annihilation of vortices also involve critical points of the velocity field, namely nodes and saddles. Identifying the simplest mechanisms underlying these processes enables us to develop an effective kinetic model that closely aligns with the experimental observations, and shows that different processes are responsible for vortex number growth and decay. These findings underscore the crucial role played by topological constraints in shaping nonlinear, turbulent evolution of two dimensional quantum fluids.