Controlled polarization of two-dimensional quantum turbulence in atomic Bose-Einstein condensates

TL;DR

This paper presents a method to generate and control two-dimensional quantum turbulence in atomic Bose-Einstein condensates by manipulating vortex polarization through obstacle-induced vortex decay.

Contribution

It introduces a novel scheme using obstacles to control vortex polarization, enabling the study of turbulence with tunable anisotropy in quantum fluids.

Findings

Controlled vortex polarization affects turbulence decay dynamics.

The scheme allows transition from anisotropic to isotropic turbulence.

Numerical simulations demonstrate effective polarization control.

Abstract

We propose a scheme for generating two-dimensional turbulence in harmonically trapped atomic condensates with the novelty of controlling the polarization (net rotation) of the turbulence. Our scheme is based on an initial giant (multicharged) vortex which induces a large-scale circular flow. Two thin obstacles, created by blue-detuned laser beams, speed up the decay of the giant vortex into many singly-quantized vortices of the same circulation; at the same time, vortex-antivortex pairs are created by the decaying circular flow past the obstacles. Rotation of the obstacles against the circular flow controls the relative proportion of positive and negative vortices, from the limit of strongly anisotropic turbulence (almost all vortices having the same sign) to that of isotropic turbulence (equal number of vortices and antivortices). Using the new scheme, we numerically study quantum turbulence and report on its decay as a function of the polarization.