Momentum distribution of Vinen turbulence in trapped atomic Bose-Einstein condensates

TL;DR

This paper numerically investigates the momentum distribution and energy fluxes in Vinen turbulence within trapped Bose-Einstein condensates, revealing a characteristic power-law momentum spectrum and particle cascade during vortex decay.

Contribution

It provides the first detailed numerical analysis of momentum distribution and energy fluxes in Vinen turbulence in trapped BECs, highlighting the coexistence of wave turbulence and particle cascades.

Findings

Observation of a $k^{-3}$ momentum spectrum in turbulent BECs

Identification of a direct particle cascade during vortex decay

Confirmation of Vinen turbulence characteristics in trapped BECs

Abstract

The decay of multicharged vortices in trapped Bose-Einstein condensates may lead to a disordered vortex state consistent with the Vinen regime of turbulence, characterized by an absence of large-scale flow and an incompressible kinetic energy spectrum $E\propto k^{-1}$. In this work, we study numerically the dynamics of a three-dimensional harmonically trapped Bose-Einstein condensate excited to a Vinen regime of turbulence through the decay of two doubly-charged vortices. First, we study the momentum distribution and observe the emergence of a power-law behavior $n(k)\propto k^{-3}$ consistent with the coexistence of wave turbulence. We also study the kinetic energy and particle fluxes, which allows us to identify a direct particle cascade associated with the turbulent stage.