Counterflow Quantum Turbulence and the Instability in Two-component Bose-Einstein Condensates

TL;DR

This paper investigates how counter-superflow instability in two-component Bose-Einstein condensates leads to quantum turbulence, revealing the nonlinear dynamics and potential experimental observation of vortex tangling.

Contribution

It provides a theoretical analysis of the nonlinear evolution of counter-superflow instability and demonstrates the transition to quantum turbulence via numerical simulations.

Findings

Counter-superflow instability triggers soliton and vortex formation.

Vortices become tangled, leading to quantum turbulence.

The process is feasible to observe in 2D trapped BEC experiments.

Abstract

We theoretically study the nonlinear dynamics of the instability of counter-superflow in two miscible Bose-Einstein condensates. The condensates become unstable when the relative velocity exceeds a critical value, which is called counter-superflow instability. We reveal that the counter-superflow instability can lead to quantum turbulence by numerically solving the coupled Gross-Pitaevskii equations. The modes amplified by the instability grow into solitons and decay into quantized vortices.Eventually, the vortices become tangled and quantum turbulence of two superfluids. We show that this process may occur in experiments by investigating the dynamics in a 2D trapped system.