Dispersive bottleneck delaying thermalization of turbulent Bose-Einstein Condensates

TL;DR

This paper investigates a dispersive bottleneck in turbulent Bose-Einstein condensates that delays thermalization, revealing a transient partial thermalization phase and vortex disappearance, with implications for classical turbulence models.

Contribution

It identifies a dispersive bottleneck mechanism causing delayed thermalization in turbulent BECs, introducing the concept of spontaneous self-truncation due to dispersive effects.

Findings

Transient partial thermalization observed before equilibrium.

Vortices disappear prior to final thermalization.

Dispersive effects induce a self-truncation delaying thermalization.

Abstract

A new mechanism of thermalization involving a direct energy cascade is obtained in the truncated Gross-Pitaevskii dynamics. A long transient with partial thermalization at small-scales is observed before the system reaches equilibrium. Vortices are found to disappear as a prelude to final thermalization. A bottleneck that produces spontaneous effective self-truncation and delays thermalization is characterized when large dispersive effects are present at the truncation wavenumber. Order of magnitude estimates indicate that self-truncation takes place in turbulent Bose-Einstein condensates. This effect should also be present in classical hydrodynamics and models of turbulence.