Evidence of power law behavior in the momentum distribution of a turbulent trapped Bose-Einstein condensate

As a consequence of the quantization of its vorticity, superfluid systems may present the simplest form of turbulence and the exploration of turbulence in Bose condensed gases may create a gateway to better understand various turbulent phenomena. In this work, a magnetically trapped atomic condensate of 87Rb atoms is used to investigate the emergence of quantum turbulence. Vortices and anti-vortices are generated by applying an off axis, sinusoidal, magnetic field gradient and agitating the condensate to inject kinetic energy. Vortices are created on the periphery and propagate through the cloud, setting up experimental conditions favorable for turbulence. Once a turbulent regime has been produced, the condensate is released from its trapping potential and allowed to freely expand. Measurements of the atomic density profile after a time of flight are used to gain insight into the in situ momentum distribution of the system. These images show clear deviations between the non-turbulent and turbulent density profiles, in both the distribution of momentum and its average magnitude.FAPESPCNP