Synthetic dissipation and cascade fluxes in a turbulent quantum gas.
Science
; 366(6463): 382-385, 2019 10 18.
Article
in En
| MEDLINE
| ID: mdl-31582522
ABSTRACT
Scale-invariant fluxes are the defining property of turbulent cascades, but their direct measurement is a challenging experimental problem. Here we perform such a measurement for a direct energy cascade in a turbulent quantum gas. Using a time-periodic force, we inject energy at a large length scale and generate a cascade in a uniformly trapped three-dimensional Bose gas. The adjustable trap depth provides a high-momentum cutoff k D, which realizes a synthetic dissipation scale. This gives us direct access to the particle flux across a momentum shell of radius k D, and the tunability of k D allows for a clear demonstration of the zeroth law of turbulence. Moreover, our time-resolved measurements give unique access to the pre-steady-state dynamics, when the cascade front propagates in momentum space.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Science
Year:
2019
Document type:
Article