Synthetic dissipation and cascade fluxes in a turbulent quantum gas

Journal article

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 kD, which realizes a synthetic dissipation scale. This gives us direct access to the particle flux across a momentum shell of radius kD, and the tunability of kD 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.

Authors: Navon, N; Eigen, C; Zhang, J; Lopes, R; Gaunt, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Association for the Advancement of Science
• Journal: Science
• Volume: 366
• Issue: 6463
• Pages: 382-385
• Publication date: 2019-10-18
• Acceptance date: 2019-09-25
• DOI: 10.1126/science.aau6103
• Keywords: FFR