skip to content

Vortex Dynamics and Turbulence in Confined Quantum Gases

Presented by: 
N Proukakis Newcastle University
Thursday 6th December 2012 - 14:40 to 14:55
INI Seminar Room 1
Session Title: 
Quantized flux tubes and vortices
Session Chair: 
Robert Kerr
Quantised vortices are known to arise in ultra-low temperature quantum gases as a result of targeted vortex generation (e.g. via phase imprinting or a 'quantum stirrer') or intrinsic system fluctuations. Such vortices interact dynamically, reconnect and can form regular ('lattices') or irregular (turbulent) structures, depending on the system conditions. Focusing initially on the issue of tangled vorticity, we show that the velocity statistics provides a unique identifier of 'quantum' vs. 'ordinary' turbulence, in agreement with related studies in helium. As quantum gas experiments typically feature harmonic confinement, one does not have access to the broad lengthscales relevant for helium, with the total number of vortices typically constrained from a few to a few hundred. In a first attempt to probe 'turbulence' in such systems, we go beyond the usual procedure of looking at the energy spectrum to discuss methods to quantify and ana lyze the amount of clustering of vortices using information extracted from their position and winding, focusing here on the two-dimensional regime. As realistic cold atom experiments are conducted at non-zero temperatures, where the condensate co-exists with a thermal cloud, we also study how temperature modifies the motion of vortices in such systems.

This work has been generously funded by EPSRC.
The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.
University of Cambridge Research Councils UK
    Clay Mathematics Institute London Mathematical Society NM Rothschild and Sons